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CMF3 1237-series design and build progression

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#51 Rick Moore

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Posted 20 July 2017 - 11:40 AM



A lot has happened over the course of the 1237-series progression to get to this point. The quick overview of the CanAm class chassis would be:


- The 1237-series are characteristically superior to previous 1219-series designs; some component structures of the 1219-series are not advantageous/necessary in the 1237-series.

- Framing in 0.032” wire has become the norm (for all classes).

- The 1237’s and 1245’s are the elemental core designs within the series.

- Design and structural modifications on the 1241 (ex 1244 design mods) negated subsequent designs/builds (1246 - 1249).


The next step would be to structurally combine the 1237 and 1245 designs with the same dynamic functionality as the 1241, and hopefully incorporating all the positive attributes of those designs. Yeah.


And that design is the 1250. This one was doodled out some time ago, shortly after the 1241-Cc3, with constant revisions right up into the build itself…


On the 1250 the basic center main rail and buttress rails of the 1237 are retained; the front axle rails of the 1241 are redesigned appearing as the buttress rails were on the 1245, but with the required structural modifications.


Nothing to it…


Of course, I’d be sticking to the all-familiar “c” dimensions for first-build baseline comparisons.


And the 1250-Cc3 looks like:















Initial calculations and guesses indicated the completed car without any pans would wind up about 96.5 grams; so two 0.025” semi-static brass pans were added adjacent to the central main rail. And, of course, a sissy bar was added after mounting the first body. When it all was done the RTR car came out to 100.0 grams… not bad for a WAG… better to be lucky than good… works for me…


Considering how well the 1241’s run, especially after the results of the 1241-Cc3’s last race outing, this design had its work cut out for it before it ever got on the track…


Test run:


Wednesday evening test & tune, Fast Eddie’s Raceway on the Hillclimb…


Still sorting through the “test” motors… After a second motor change on the 1241-Cc3 (the first being put in the “for later use” pile, the second dumped among the “ugh-slow” motors), I got two motors that were pretty much equal, so the comparison was better than usual with less guess-timation (and found a third equal pony in the 1245-Cc2…).


(Also still playing around with controllers, but that’s another story…)


The “feel” driving the 1250-Cc3 was every bit as good as the 1241-Cc3; smooth, predictable, consistent, and fast. The 1250-Cc3 was quicker on Orange, quite an accomplishment as the 1241-Cc3 has been the quickest since it got built. On Black, the 1241-Cc3 has been fastest (along with the 1245’s), and was at best about 0.02 s faster than the 1250-Cc3. On Red, where the 1237’s have tended to be best, the 1250-Cc3 ran an all-time best lap (with a test motor), but still only about 0.02 s faster than the 1241-Cc3.


Not sure how the 1250-Cc3 is more characteristically similar to the 1237’s than the 1245’s, or the 1241-Cc3 more like the 1245’s than the 1237’s, which is intuitively backwards, but there it is nonetheless… Have to think about that some more…


Anyway, on the gutter lanes they balance out, but averaged across all lanes the 1250-Cc3 was “faster” than the 1241-Cc3. “Better” is more subjective, but the 1250-Cc3 is every bit “as good” as the 1241-Cc3. From this initial run I’d say any further decisions as to car of choice between these two cars would have to be made in race trim. But, of course, more testing to come…


Not bad… A bit confusing, but not bad…


I think I’m starting to have fun with this slot car thing…


Rick / CMF3

#52 Rick Moore

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Posted 09 August 2017 - 10:57 PM



I wanted to have another CanAm-Plus class car to go along with the 1237-Cb3+, just because I wanted to have another one... or something like that… It was coming down to either a 1241 or 1250 version, but since with the CanAm class cars the 1250-Cc3 was more like the 1237’s characteristically, and similarly the 1241’s were more like the 1245’s, I decided a CanAm-Plus version of the 1241 might give a different option over the previous CA+ class 1237… or something like that…


So, with smaller fronts and without the dynamic pans on its CA sister, this is the CA+ class 1241-Cc3+:













The RTR 1241-Cc3+ weighs 94.9 grams; that’s 6.1 grams less than the CanAm sister 1241-Cc3, but 4.7 grams more than the previous other CanAm-Plus class build, the more structurally minimalistic and 0.125” shorter 1237-Cb3+. I have no problem with the greater mass for this class car, since the 1241-Cc3+ was less of a test of relative mass the 1237-Cb3 had been in concept, and more a test of the applicability of certain chassis dynamics between classes (which had been successfully explored between the 1241-Cc3 and its other sister build, the Stock Car class 1241-D3o, but for slightly different reasons than what might have been expected…). That, and I also wanted to see the fit of the “c”-dimensioned chassis under the Gulf-Mirage body.


Test Run:


Forced to do another evening of testing at Fast Eddie’s… Just terrible, right?


So the real question was would the CA-Plus 1241 and 1237 versions show the same relative differences in characteristics as the CanAm versions, the 1237 being better on the upper-gutter/Red lanes and the 1241 better on the lower-gutter/Black…


No. These lighter stripped-down CA+ versions seem to be better all-around cars across all lanes. If anything the relative gutter-lane characteristics of these two CA+ chassis may be reversed with their respective CA counterparts, but, at least after these first comparative test runs, that would be marginally. I will give a first-outing nod to the 1241-Cc3+ being a bit more consistent, and, though it had what should have been the slower motor, could turn fast laps one right after another; but more tests are in order as track condition (slightly loose) may have been a contributing factor.




Got to try the new Parma ’69 Charger stock car body on the 1241-D3o. Not sure if it’s any faster than the Cyclone, but I love the way it looks… looks fast just sitting there... sweet.


Still playing around with the old moly-graphite RF guides versus the new nylon RF guides; still, no noticeable improvement in lap times or drivability on any chassis thus far. Your results may vary…


And, just to put this out there, despite a much steeper learning curve, and just getting my finger used to it, my “go-to” controller has become the ProModel PMCR, over the S&K which had bettered my Difalco HD30. That’s a tough one to call, as all of these are great controllers, and it really comes down to that subjective what feels “right” in your hand running your car. While the availability and overall price of the ProModel will be a deal breaker for some, which I fully understand (I just got one to try because I couldn’t find anyone who had one… curiosity killed the tax return…), my $0.02 is the ProModel is one killer tuning tool to have in your slot box (or boxes… who are we trying to kid…).


That’s all folks!


Rick / CMF3

#53 Rick Moore

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Posted 25 September 2017 - 01:18 PM

Racing Update:


For all you competition freaks, the latest fix...




(Honestly, I’d love to be able to get to other races at other raceways, not just in GRRR but other regions, to try these 1237-series cars out “under fire”, and for the fun of it, but at this point, especially after the beating my personal finances took for the better part of a dozen years or so back-when, I’m just not willing to give up my weekend work schedule at the hospital, where I also get the weekend and graveyard shift differentials; besides that, the occasional weekday shift openings that do come along are more important to some of my coworkers who are younger and need a little more normalcy, raising families… Anyway…)


A little R&R was needed from work, and what better way than to take the weekend off so I could participate in the GRRR races at Fast Eddie’s Raceway on Sunday September 24.


Let me preface this post, talking about motors. I have found that bench testing of the HR motors is all well and good, but at this point I am largely convinced you don’t know squat until you start trying them in different cars. Sure, bench testing helps to get them in some sort of order to start track testing, but after that it really doesn’t mean much… Some of my fastest “track” motors are ones that were in the mediocre “bench” motors, and vice versa… And just because one motor works “great” in one chassis/car does not necessarily mean it will be equally “great” in another chassis/car… While it is nice to know there are more options available than initially thought, it is a lot more work in the long run… I don’t know, maybe it’s just me… Your results may vary…


Anyway, this is what I got pre-race testing:


For the Stock Car class, to be run on the Oval, I had been testing my two left-turn-only retro stocker chassis, the 1237-D2o and 1241-D3o. The 1237-D2o had won its maiden race in this class, the previous GRRR stock car race at Fast Eddie’s back in January, and with subsequent set-ups was running faster and better; the 1241-D3o was easily as fast, and with a few set-ups a little faster. I was leaning toward the 1241-D3o right up until Saturday evening, after the FSCS races, when I ran some practice laps with both cars again, and changed my mind when I made the gut-call that I could turn more race laps with the 1237-D2o…


For the CanAm class race car I had been concentrating on testing six cars, the 1237-Cc3, 1237-Cb3, 1245-Cc2, 1241-Cc3, 1241-Cb3, and 1250-Cc3. The benchmark had been set by the 1241-Cc3 at the last GRRR CanAm race in June at Fast Eddie’s, setting new qualifying (4.538) and total race laps (291) records for the class on the Hillclimb (including the GRRR races when the track was in Jacksonville); it was my first car in the 4.5’s, so the idea was to get other cars with set-ups in that range. In test trim (virtually always slower than race trim) I was able to get the 1237-Cc3, and 1237-Cb3 into the 4.63 - 4.60 range, which was pretty good (would have been “great” back in January, but after June…); the 1245-Cc2 and 1241-Cb3 got in the 4.59 - 4.56 range; and the 1241-Cc3 and 1250-Cc3 could run 4.54 - 4.50, which also confirmed the qualifying run in June wasn’t some fluke “hare lap”. It really came down to the 1241-Cc3 and 1250-Cc3; both are easy to drive, and drive fast, and both are capable of running the gutters in the low 4.6’s. The Wednesday before the race I got them into semi-race trim, and it was still a close call between the two, whether on Orange, Red, or Black; but the 1241-Cc3 was just a hundredth or two faster on all, and a little more consistent. Finally the 1241-Cc3 ran a 4.492 on Orange (my first 4.4-anything), so it got the nod as my CanAm class race car again, while keeping the 1250-Cc3 ready as my back-up car.


For the “IMSA” race on the Hillclimb (a combo-class race running CanAm Plus and GT Coupe at the same time), since I’d run the weighted-up 1237-Cc2 in GTC back in January (2nd place), I wanted to run one of the two CA+ cars I’d built since then for this race. If I had not built the 1241-Cc3+ for this class I would have had no problem running the 1237-Cb3+ for this race, but it may never get that chance now; I found a set-up (again, with a “mediocre test motor”…) on the 1241-Cc3+ that was running consistent low 4.5’s with ease, and after it ran a set of 4.50X’s I took it off the track (instead of pushing it to see if I could squeak out a 4.4-something), made my notes, and put it back in the box for this race.


(Here’s a FYI side-bar for all us slot car geeks who like to stash away little tidbits of info in our little noggins: For the GRRR races in August and September of 2016 I used my Difalco Genesis HD30 controller, and this year in January and June I used my S&K controller; for these races I would be using my ProModel PMCR ICE Compressor 2 controller (or as I like to call it, my “curiosity killed the tax return controller”). I’d spent about a month after the June race trying to “come to grips” with the ProModel, and doing comparison testing with the S&K; after that I was using the ProModel exclusively…)


Being only two weeks post-hurricane Irma, we were wondering how turn-out would be for the GRRR races. H-Irma had also postponed the last FSCS races, also to be held at Fast Eddie’s, and were rescheduled for Saturday, the day before the GRRR races on Sunday…


Oh yeah, I was holding the drawing for the CMF3 1237-Cc3 United Mitochondrial Disease Foundation (UMDF) Fundraiser Slot Car too.


Race Day:


The UMDF 1237-Cc3 drawing was held before the races started. Congratulations to the winner, Bryan Warmack!


Turnout, as was thought it might be, was a good bit lower than previous GRRR events at Fast Eddie’s…


As for the races:


First was Stock Cars on the Oval; six entries, no qualifying. Jeff Bonanno and I were literally running side-by-side and trading the lead all the way into the sixth heat! In the end I got a lead over Jeff, and the 1237-D2o finished 1st, setting a new lap record (2 min heats) of 254 laps. (In fact, the first five cars all beat the previous lap total record, set by the same 1237-D2o at the last race of 242, and all five also ran higher lap averages than the prior 3-minute heat race in 2016!)


Next up was CanAm on the Hillclimb; nine entries. The 1241-Cc3 qualified first, running the only sub-4.60 lap at 4.568 despite the driver doing a pretty lousy job. Another good race, this time fighting for the lead with Roger Whobrey, who drove a great race finishing second with a lap total of 291 (tying the record I set at the last race), but again I was able to get the 1241-Cc3 to pull ahead, winning the race with a new CanAm class total lap record for the track of 295.


The final race of the day, on the Hillclimb, was the “IMSA” race for GT Coupe and CanAm-Plus; six entries (four GTC and 2 CA+), no qualifying. The 1241-Cc3+ was able to show exactly what a good CA+ car should do racing against the much heavier GTC’s, finishing first in class and overall, while setting an outright retro lap total record for the Hillclimb of 298 laps, ten laps ahead of the second place overall / first place GTC of Roger Whobrey (another good drive, his 288 tying the lap record for GTC).


So, for these three chassis:

1237-D2o - 2 races; 2 wins (2 lap total records)

1241-Cc3 - 2 races; 2 top qualifiers (class qualifying record), 2 wins (2 lap total records)

1241-Cc3+ - 1 race; 1 win (1 lap total record)


Not bad…




All-in-all a fun day. Never enough thanks: to Grant Goerner for all his effort and time keeping the GRRR series humming along: to Ed Hoffman (and Elaine) for giving me and the other FL Left-Coast slot car geeks a great place to play with our cars; and to the volunteer turn-marshals! And it’s always great to see all the other slot car geek “kids” at the races (even the “grumpy ones”, LOL).


As for how “good” these weird wire contraptions of mine are compared to other scratchbuilds… well… I’ll let y’all be the judge of that… My subjective view is I’m happy with ‘em, and having ton o’ fun at that.


Happy and fun is what it’s all about…


Later, kids!


Rick / CMF3




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#54 Bill from NH

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Posted 25 September 2017 - 05:52 PM

Not many others can say they run & win with something they built. :)  It's a third dimension of the hobby.

Bill Fernald
I intend to live forever!  So far, so good.  :laugh2:  :laugh2: 

#55 Rick Moore

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Posted 26 October 2017 - 10:11 AM



Before setting off into the next set of new chassis designs (consider that a warning), I had one more iteration of the previous builds to consider…


Yep, another 1241 CanAm class chassis. Since I’ve got a pretty good understanding of the 1241s’ chassis characteristics, and with the original 1241-Cc3 posting up some TQ’s, wins, and lap records (and doing this despite the driver being “average” at best), I figured I’d be foolish not to use this design to explore one more dimensional variation that I’ve wanted to revisit for some time... So, since I already had the 1241-Cc3 and the 1241-Cb3, it was time to make a 1241-Cd3…


Some designs/builds and time ago, I had explored a single design, the 1229, with multiple builds using different dimensions: wheelbase (WB); rear axle to guide pivot center (RAX-GPC); and the resulting front axle to guide pivot center or guide lead (GL). This yielded the 1229-Ca2, 1229-Cb2, 1229-Cc2, and 1229-Cd2.


Those 1229’s, as their designations (“2”) indicate, were all built using 0.039” wire. The 1241’s are all 0.032” wire framed chassis.


Though not to say there were not tracks and conditions when the 1229-Ca2 or 1229-Cb2 could be the best choice, the 1229-Cc2 and the 1229-Cd2 were my “go to” chassis at that time. Also, the 1229-Cd2 had been one of the quicker and more consistent test platforms of all the 1229’s on the Hillclimb at Fast Eddie’s back when I started this thread and was first testing the 1237-series chassis…


So, the question is: Would the 1241-Cd3 have the same relative handling/driving characteristics in the 1241’s as the 1229-Cd2 had among the 1229’s…


For reference, here’s the ID and dimensional differences (no, not all of them), listed longer to shorter, in inches, as WB / RAX-GPC / GL:


a =   4.000 / 5.000 / 1.000

e =   3.875 / 5.000 / 1.125

c =   3.875 / 4.875 / 1.000

d =   3.750 / 4.875 / 1.125

b =   3.750 / 4.750 / 1.000 …


I haven’t built any “long” chassis (WB > 3.875”) since the 1229’s, when I was making the switch from 0.047” to 0.039” wire framing, and further exploring 0.032” wire framing; I had learned on the 1225-Ca3 it was prudent to limit the relative lengths of structures within the chassis when building frames using smaller wire…


Anyway, this 1241 “d-dimensioned” car I’ve been wanting to build would have the same RAX-GPC as the 1241-Cc3, the same WB as the 1241-Cb3, and yielding an atypically longer GL than both…


…making the 1241-Cd3, not surprisingly, look like this:















The sharp-eyed (which rules out most of us overgrown slot car kids) will notice the previously noted not-so-usual longer guide lead on this one. Also visible, the 1241-Cd3 has shorter side pans and longer front wings than the 1241-Cc3 (however the main rail and buttress rails are the same lengths). Other than that, the 1241-Cd3 looks just like the 1241-Cc3. (and 1241-Cb3)... Side-by-side-by-side:


1241-Cc3 (left); 1241-Cd3 (center); 1241-Cb3 (right)





And, like the 1241-Cc3, I figured the 1241-Cd3 would not need any added lead for the you-know-what rule. The RTR car came out to 100.4 grams.


Test Run:


First motor I put in the 1241-Cd3 was lacking brakes, but I noticed it was handling this rather well. The next motor was a mediocre one with good brakes from another car that 1241-Cd3 was able to crank out laps about 0.05 s faster. This was getting interesting… so I made one more motor change…


On Orange and Blue lanes the 1241-Cd3 was every bit as fast as the 1241-Cc3 and 1250-Cc3, running 4.5’s; and though 0.03 and 0.01 seconds slower than their best laps respectively, the 1241-Cd3 was turning fast laps more consistently. On the gutter lanes, Black and Red, the 1241-Cd3 was outright faster than either the 1250-Cc3 or 1241-Cc3 (both of which can run low 4.6’s on the gutters), turning sub-4.60 laps… the first any of my cars have run on the gutters… and only a couple of hundredths slower than the 1241-Cd3 ran on Orange and Blue… this is definitely getting interesting…


So, the answer is: Yes.


Okay, that ties up that loose end… at least for the time being… with the time being it’s time for more testing… and it is time to move on to the next design and build…


Hey, I warned you a long, long time ago this post could go on interminably to the point you’d be bored into a coma, and/or additional chassis posts may warrant additional medication… might be time for a real big dose… if you have any extra, please share…


Rick / CMF3

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#56 Rick Moore

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Posted 16 November 2017 - 11:42 AM



Moving on…


In the case of this design, the 1251, testing relative to the 1250-Cc3 and the 1241-Cc3 had prompted curiosity into further exploration of the design and incorporation of the front axle rails (FAR’s) within the basic 1237-series chassis design… which on the 1251 are quadrangular structures with no direct attachment to the buttress rails or main rail…


That’s the abridged version… let’s keep it like that, before I get to typically typing too much…


The 1251-Cc3 is still 0.032” wire framed (“3”), and keeps the generally favored 3.875/4.875/1.00” dimensions (“c”) for comparison purposes.


In any case, the 1251-Cc3 comes out like this:



















With the 1251 there is no adjustable bite bar, just as there wasn’t on the 1250, or 1245’s (if at any time it is deemed warranted it can be reengineered into the design). Of note, the 1251’s dynamic pans are suspended within but not attached to the FAR’s; had to get them in there somehow for that ding-darn 100-gram minimum thing…


In actuality, after getting all the runny bits on and the body mounted along with the “sissy bar”, the RTR for the 1251-Cc3 is 101.7 grams…


I realized during the build that the 1251 is a prime candidate for building another “d-dimensioned” car, something I might have to consider in the future, depending on…


For all intents and purposes, the 1251 is a slightly redesigned 1241. But it was a redesign that had to be done before venturing any further. However that redesign was enough to make the build more, for lack of a better word, involved. So, to warrant its creation, and any further creations and variations, the 1251 cannot be “as good” as the 1241’s, it needs to be “better”… and that is quite a tall order. But with slot car chassis you just never know until you build it and get it out for a…


Test run:


Another evening at Fast Eddie’s Raceway, testing and tuning… Yeah, it’s a dirty job, but someone’s gotta do it…


I did a lot of motor swapping this time out, comparing the different chassis/cars with various but the same ponies. This made for a jumble of info. Even before I got it all sorted out it was apparent the 1251-Cc3 was every bit as good as the 1241-Cc3; fast, predictable, and easy to drive. But so are the 1241-Cd3 and 1250-Cc3, both of which rather unexpectedly showed faster times with some of the motor/gear/tire combinations. The 1250-Cc3 was just outrunning everything last night, and in one set-up even cranked out an easy sub-4.50 s lap that was faster than the 1241-Cc3’s best and only other sub-4.50 s lap (4.481 vs 4.492 respectively), which I would not have expected with the track conditions…




Anyway, as it currently sits the 1251-Cc3 would have to be considered a “failure”, due to it being more involved to build than the 1241’s, even though it is easily one of my four fastest chassis/cars. The 1251 needed to be “better” than the 1241’s…


But, until last night, I was pretty much thinking the 1250-Cc3 was also a “failure”, since it too had yet to prove “better” than the 1241-Cc3…


More testing to come, of course…


As I said, you just never know…


In the meantime, what to build next…


Rick / CMF3

#57 Rick Moore

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Posted 13 December 2017 - 10:06 PM



The F1’s in this progression sort of got stuck on the back burner… actually, more like they got put in deep-freeze… There were no F1 races scheduled at Fast Eddie’s Raceway in the 2017 GRRR series, and with my work schedule (some of you may recall I’m one of those freaks who works the weekends shooting x-rays at a big hospital…) it was highly unlikely I’d get to any other FL raceways to run the F1 races, or any other races at all, that were scheduled.


But this design had to be built regardless. There just wasn’t any rush to do so. Since I hadn’t built an F1 for a while, this seemed like as good of a time as any…


The A218-e3 is, for all consideration, the A216-e3 redesigned to incorporate what I’d learned on the 1241 CanAm design and builds. Basically, the A216 had the front axle rails lateral to the buttress rails, while the A218 has these components swapping positions with the front axle rails medial to the buttress rails. The A218 is again built to “e” dimensions so as to build it using the “3” designated 0.032” wire framing.


So the A218-e3 looks, not too surprisingly, like this:















Of note, the A218-e3 now has the Parma 1060B McLaren M7 body mounted, as opposed to the Parma 1038B Matra MS80 body used on the A214-c2, A215-c2, A216-e2, and A216-e3. One result in this change of body is the A218-e3 has a relatively longer reinforced front fork to fit the larger and more forward placed M7’s front wings. (I could’ve put a M7 on the A216-e3 for better testing comparison, but I already have a good idea how the chassis structural changes would manifest, and if this was the case there was little sense using up a body on the A216-e3; if things proved different, I could always put an M7 on it too.) While framing the chassis out, and aware of the M7 lexan lid for this car, I decided to build up and shape the front tines so they would fit snugly under the front wings of the McLaren body; like this:







The thought (term used loosely) was that it might take better advantage of any downforce afforded by the body front wings and apply it more directly to the chassis front and guide… with the afterthought that it probably won’t matter diddly, but it was fun making it, and I think it looks kind of cool anyway.


The RTR car came out to 99.6 grams; to make the (derogatory term omitted) F1 class minimum 100-gram weight, a small piece of the dreaded lead was added to bring it up to 100.0 grams.


Test Run:


Short test session. Pretty easy to call this one. The A218-e3 easily ran the flat-out fastest laps of any of my F1’s on the Hillclimb at Fast Eddie’s, on orange, black, and red. It wasn’t even close. I left the car in its “out of the box” set-up; didn’t play with tires, motor, gearing, nuttin’; I just got lazy; however, I did finally get to play around with the ProModel controller, something I hadn’t gotten ‘round-2-it with the F1’s since getting it this year, and things only got better… Sure, the body might have some to do with it, but not near all of it… More testing is in order on the A218-e3, most certainly, working on the set-ups… But, for a first run, not bad.


Besides, I’m already building the next chassis…


Rick / CMF3

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#58 Rick Moore

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Posted 20 December 2017 - 09:33 PM



Here we go again...


Holy cow! It’s the 1244!


This asymmetric retro Stock Car chassis design has been lurking around for some time, mostly as a lot of scribbles and doodles in the notebooks. The 1244 has probably gone through more adaptations, variations, and incarnations than any chassis design of mine to date, even more than the original 1237 design. However, while doodling around on the 1244 all that time there would be a lot of design and construction ideas that would contribute to and find their way into other designs and builds, like the 1245’s, 1241’s, 1250, and 1251… It also contributed heavily to the 1252, another asymmetric LTO stock car chassis design that is currently residing in the same scratchbuilding purgatory where the 1244 had been lurking for so long…


Okay, let’s do this… finally…


As I said before, the 1244-D3o is an asymmetric retro Stock Car chassis design, solely for oval track racing, a left-turn only (LTO), hence the “o” at the end of its alphanumeric moniker. By asymmetric I mean the left side and the right side framing aren’t the same; in the case of the 1244 the left side is basically a 1241 design, while the right side is a 1250 design. If I had built the 1244 way back when, prior to the 1241 and 1250, that would have been a lot harder to explain, so let’s just leave it at that.


As with the 1241-D3o, I framed the 1244-D3o out in 0.032” wire.


The 1244-D3o:





















On the 1244-D3o the pans, not surprisingly, appear just as they do on the 1241-D3o on the left-side; while the right-side looks like a stock car version of a 1250, it is devoid of pans (well, except the static rear pans, but they don’t count). Out-of-the-box the 1244-D3o RTR car came out to 115.4 grams… yeah, I know about the 120-g minimum weight thing...


Both previous 1237-series oval retro stock cars were under 120 grams out-of-the-box; the 1237-D2o at 119.3 grams, and 1241-D3o at 118.1 grams. Their current race configurations with added lead ballast are 129.5 grams and 124.5 grams respectively. By all observation these RTR weights would be considered “light” for this class…


The 1241-D3o, besides proving a 0.032” wire-framed retro stock car chassis was viable, showed me that overall mass is not as important as chassis dynamics, even with these relatively big honker stockers; I was genuinely surprised and pleased how much lead I could take back off… So I saw no reason not to continue in this direction.


Similarly the 1244-D3o will start out at its OOTB RTR weight, and with testing and tuning a more regulation acceptable final mass should be achieved… Granted, there is 4.6 grams to go before this thing hits the 120-min. I figure if I tacked on six to ten grams on the last two cars for that LTO bias, this one should be no sweat. As on the previous chassis, I precut a bunch of lead to fit the left side pans on the 1244-D3o, so this will be easily accomplished, using various mass distributions and totals, so we’ll see where the final weighted RTR comes out… subject to change, of course…


Test run:


Wednesday evening, Fast Eddie’s Raceway, on the Oval… life (with slot cars) is good…


Keeping in mind the 1237-D2o won both of the races it has been entered in, and the 1241-D3o is just as fast, I was real curious to see how the 1244-D3o would stack up.


Out of the box it was immediately obvious the 1244 was going to be fast; an added 0.010” change of guide depth, and it was already handling better (maybe “easier” would be the correct term) and faster than both the 1237-D2o and 1241-D3o. Trying to keep the total weight as low as possible I added a minimum of lead to the left side pan, front wing, and the forward portion of the semi-static pan, bringing the weight to 119.7 grams, just under the class 120-g minimum; the 1244-D3o ran laps faster than any previous fast laps turned either in practice or in a race…


I have no intention of adding any more lead until this car would go into race trim, and then only enough to make it 120.0 grams, no more. It doesn’t need it.


Honestly, I did not expect a Stock Car this light to work anywhere near this well. Shows you how much I know… and I keep asking myself…


So, exactly WHY did I put off building this thing for so long?


Rick / CMF3

#59 Rick Moore

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Posted 03 January 2018 - 10:34 AM



GT Coupes… yeah, well…


Here’s the thing about GTC’s: typically if I want to run in the GTC class I take a CanAm chassis and slap on enough lead, a lot of lead, to make the 110-gram minimum. A description of my general attitude in regard to adding lead to a chassis would involve derogatory declaratives with profuse profanity. My current inventory of GTC’s consists of the 1237-Cc2 and the 1121-Cc4, and, as noted, with a boat-load of ballast added to them.


Some years back I built the 1229-Ca, the last chassis I built using 0.047” wire for the framing, as the 1229’s were meant to be 0.039” wire framed chassis from the onset (and would lead to the first successful 0.032” wire framed chassis as well). I built the 0.047” wire 1229-Ca to be a purpose-built GTC car. It came out RTR at 110.5 grams (not needing any added lead), and it worked very well… but still not as well as its 0.039” wire CanAm sisters…


Well, I figured it was about time to try to make another purpose-built GTC again, now that I’m neck-deep in the 1237-series. My original thought was to do similarly as had been done on the 1229, and just build one of the 1237-series designs using a larger, in this case 0.039”, wire. But while looking at my left-turn-only 1237-series Stock Cars and the left-side pans on those cars I figured I could do that on both sides of a CanAm chassis design/build, still frame using 0.032" wire, and get a lot closer to the 110 grams…


I opted for the successful 1241 design for this GTC project, for obvious reasons… However, for this GTC version I decided to build it using “d” dimensions (instead of the usual “c”) for two reasons:

1) The “d” dimensions would make the addition of the extra pans relatively easier;

2) I had noticed previously that the heavier mass-added GTC’s tended to exhibit greater drop-off in performance, relative to their lighter CanAm versions and counterparts, moving towards the gutter (Red/Black) lanes; testing has shown the 1241-Cd3 to be the CanAm chassis that exhibits the least amount of drop-off in lap times from center to gutter lanes (and, on the Hillclimb here, on Red and Black lanes the outright fastest lap times for CanAm class); my hope was to get this better performance on the gutters with this GTC.


So, the panned-up 1241a-Cd3 came out like this:















Lots of pans. Anyway, besides the usual 0.010” brass sheet rear flanking static pans forward of the rear wheel-wells, a small wire was added between the lateral and medial (motor box) rear axle upright wires to frame this space completely at the rear to add another 0.010” brass sheet static pan to each side; 0.010” brass sheet static pans were also placed inside the side pan rails and front wings. The pans between the side pan rails and the buttress rails are semi-static 0.032” wire-framed 0.010” brass sheet. And, just like on the CanAm versions, the pans between the buttress rails and the center main rail are dynamic 0.024” wire-framed 0.010” brass sheet.


With all the requisite runny bits, sissy bar, and Parma Lola T-70 Coupe mounted up, the total mass came out to 109.9 grams…


Close enough. Not bad for a WAG of an idea. At this point I don’t see any need to make up for the 0.1 gram deficit. When this thing goes into race trim at some pre-race time in the future I’ll make up any difference to tech it at 110.0 grams.


Test run… or maybe not…


Nope. Not this week. The only thing crappier than the weather is the cold I have which seems to be stubbornly insistent that I cough up one or both of my lungs… an experience I see no reason to share with the general population (well, with some individual exclusions, of course…), instead deeming it more prudent to burrow deep within the domicile during this period of crappiness… perhaps I’ll do some slot car chassis building… ya think…


…cough… cough… cough, cough…


Rick / CMF3

#60 Pablo



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Posted 03 January 2018 - 11:40 AM

"A description of my general attitude in regard to adding lead to a chassis would involve derogatory declaratives with profuse profanity."


Concur. Only one thing stupider than having to meet a weight minimum in a wing car -

and that's having to meet a weight minimum in a class designed to promote scratchbuilding.


Bunky says "it's to keep complexity minimized and costs down"




That's why he still lives in a trailer with his mom and gets food stamps

Paul Wolcott

#61 Rick Moore

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Posted 03 January 2018 - 12:19 PM

Mr. Pablo! Kind of worries me someone who builds high quality beautiful chassis looking at my “yeah, that’ll work” builds… Hope I don’t embarrass you guys too much…


Maybe Bunky’s right… Sometimes, like now, I wish I lived with a mom* that could bring me some chicken soup… ( * any mom… for pete’s sake, any women I’d be dating would be in the grandma age range… gives me the willies just thinkin’ ‘bout it…)


With the possible exception of LTO chassis, I’ve always considered any addition of lead to a chassis, especially those to correct handling deficiencies, to be an outright failure of that chassis’ design and construction. The end result of a chassis design and build should yield the mass that is what that chassis is… if it is too light or too heavy you’re going to find out…


As for class racing minimum weight rules… well… yeah… can’t say I’m a proponent… But, just like I said before about the chassis, it is what it is… and it doesn’t make much sense peeing in the sandbox if you’re going to play there…


Hey, if you think these wire things have been weird so far, wait’ll you see the next ones! Scary thought, hunh?


Now, if you’ll excuse me, I have to pick up my left lung off the floor and put it back…


And Joey says “…”


Rick / CMF3

#62 Pablo



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Posted 03 January 2018 - 03:59 PM

Joey farted? Yup, I knew he'd agree with us :laugh2:

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Paul Wolcott

#63 Rick Moore

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Posted 18 January 2018 - 10:45 AM



Everybody run for cover…


For those of you who thought that so far the 1237-series was worse than having dental work without the benefit of an anesthetic, the next set of designs will probably make electric-shock therapy seem like a reasonable solution to your mental anguish…


With a skip over the 1252 and 1253 designs…


The 1254 is the first major deviation of the original 1237-series design; the 1254 has a redesigned rear assembly (which includes the motor box, rear axle tube and supports, adjunct motor bracket, and the flanking static side pans forward of the rear wheel wells). In a nut shell, or is that nut case, the forward aspects of the rear assembly have been angled to extend the point of convergence further forward, and additional structural rails have been added between that point and the medial and lateral rear axle tube support rails; this shortens the already relatively short length of the basic “c” and “d” -dimensioned 1237-type central main rail from the previous 2” to about 1.25” on the 1254, which is quite a bit relatively speaking. However the basic 1237-type front assembly (guide mount and front wings), and side pans remain the same, with the exception the buttress rails have been moved just a little more laterally, because…


In actuality the 1254 was back-designed from what would become the 1255/1256 designs… With the changes in the design and the construction, I decided it would be prudent to sort things out with the 1254 before diving in completely… which turned out to be a good decision…


And some of the more attentive out there (I feel your pain…) might have noticed another addition to the already convoluted alphanumeric identification system I use, in this case the “.2” after the “1254”… All apologies, but this was becoming necessary for my own benefit, as, beyond the hyphenated suffix already used for myriad variations (for class/drive type, dimensions, and size of wire framing), there are now additional varieties of design elements that can be incorporated into any base design (variants based on the 1237, 1241, 1250, 1251, on and on…) and the possibilities were becoming so numerous as to warrant an additional numeral, letter, or combination thereof, to designate the “version” of the design…


Which for this 1254 build, the “.2” designates it is a 1241-variant; for the usual inter-chassis comparison reason I’m starting with the “c” dimensions, and, as with all chassis now, it is a “3” or 0.032”-wire framed chassis…


See, I told you electric-shock would start to sound like a viable option…


The 1254.2-Cc3:















That wasn’t so bad… well… maybe not yet…


No bite bar on this one. My best WAG was this would still need the dynamic pans between the shorter main rail and more laterally located buttress rails to help get it close to that 100-gram thing… Joey farted again… or maybe that was me…


As it is the RTR car came out to 100.4 grams… you gotta love it when a WAG ain’t as bad as it could’ve been…


Test Runs:


Wednesday! Wednesday! Test & Tune Wednesday! Fast Eddie’s Raceway! Wednesday! Wednesday! Be there!


1241a-Cd3 (GT Coupe)


Leftover from the previous build’s post. While the 1241a-Cd3 GTC would of course be compared to the other two lead-added CanAm/GTC’s, more importantly it would be compared to the 1241-Cd3 CanAm sister car; that, and there are some target GTC performance numbers I’m looking for…


As a GTC, the panned-up 1241a-Cd3 is better than the leaded-up 1237-Cc2 or 1121-Cc4 CanAm’s-turned-GTC’s. This didn’t surprise me. I didn’t get the chance this time to run the gutters, but judging from the better handling characteristics I saw on this first test run, it should be even better on Red and Black.


But, when the 1241a-Cd3 GTC is compared versus the 1241-Cd3 CanAm, there is no comparison. It is still a 110-gram car, and that extra 10 grams does absolutely nothing beneficial.


1254.2-Cc3 (CanAm)


The primary comparison needed to be versus the 1241-Cc3, since the 1254.2-Cc3 is largely a 1241 with the redesigned rear assembly. As long as the 1254 with the new rear is as good as the 1241, then it is okay to proceed with the 1255 build; if it creates any adverse characteristics, that will need to be sorted out; if it is better, that would be more than acceptable…


As it was, it ran just as well as the 1241-Cc3 in this first test session. As it is, that means it’s a green light for the 1255.


Sidebar; Motor stuff


That would be “stuff” by the George Carlin definition.


Following the threads and posts “discussing” the variations in JK-HR motors has been interesting… kind of like watching some internet video of close-ups of people popping pimples or cutting cysts and squeezing all the gook out kind of interesting, but interesting nonetheless…


My current stable of active chassis designs/builds/cars include ten CanAm’s, two CanAm Plus, three GTC’s, three F1’s, and three Stock Cars; that’s twenty-one motors right there… and when you add in…


Do I have a “motor program”? Well, kind of…


Do I have a boat load of motors? Well, probably more than many… and less than some…


Do I care about any of the hyperbolic folderol going on about motors? Well, not really… sort of gave up caring… if I ever did…


Some folks take themselves way too seriously… Comments to be considered accordingly…


I mean, we’re talking toy cars here… silly little hobby… that a few of us happen to enjoy very much… fun, yeah, but still not all that important in the grand scheme of life, the universe, and everything…


Besides, I can always use more test motors… Might as well start building more chassis…


Have some fun yourselves…


Rick / CMF3

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#64 Rick Moore

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Posted 07 February 2018 - 11:18 PM



Alright, you were warned. It would be completely excusable should you decide to sit in the filled bathtub, plug in the severed power cord, and grab the bare ends…


The one or two of you keeping track of this stuff are probably wondering what happened to the 1255 and 1256… I’ll try to make this as brief as possible…


The 1254 design/build was laid out with the forward point of the rear assembly pushed about as far forward as I thought it could be placed, 0.75” further forward than the previous 1237-series chassis. The better way to visualize it is that this point of convergence (POC, for brevity) on the previous “c” and “d” dimensioned 1237-series chassis was 2.125” forward of the rear axle and 2.75” rearward of the guide pivot. On the 1254/1255/1256 designs the POC is centered 2.875” forward of the rear axle and 2” behind the guide pivot. On the 1257 I changed it once more; the POC is 2.4375” forward of the rear axle and 2.4375” behind the guide pivot; in other words, centered; makes sense, if that term is used loosely….


Before all that, the 1255 took the 1254 design, which had the redesigned rear assembly, and added a redesigned front assembly; the 1257 is the same concept/design with the aforementioned dimensional alteration. So, on the 1255/1257 the central main rail is gone… well, kind of gone…


Most chassis are visualized as front (guide mount) and rear (motor/drive) structures connected by “main rails”; in the case of the 1237-series up to the 1254 this was a single central main rail. Pretty simple…


The original 1255 was designed with this visualization reversed in an attempt to make possible a central “intersection” within the frame connecting to all other structures/assemblies, whether as connecting rails or rails that comprise the structure itself…


Might be time to start filling the bathtub… You could always skip to the pictures, in an effort to retain some semblance of sanity, but, honestly, the pictures really won’t make things any better…


On the 1255/1257 design the central main rail has been replaced by two rails that diverge from the front point of the rear assembly and running to the front spanner rail medial of the buttress rail connections; a sort of “knee-bracing” extends from the guide mount “triangle” to these rails…


Main rails… a hot topic at times… The thing is, there are something-like twelve “rails” within this frame that could be identified as “main rails” or part of the “main rails”… You’ll have to take my word it was designed and built to stay within applicable rule-sets where things like “main rails” are addressed, but, admittedly and unintentionally, the 1255/1257 really muddies things up on the subject…


This 1257 is a “.2” or 1241-variant, with “c” dimensions, and is a “3” or 0.032”-wire framed chassis…


Anyway, the pics. Take a deep breath, relax… The 1257.2-Cc3 looks like…

















Blinking or rubbing your eyes will not make this any better. See what I mean about “main rails” on this thing? A whole bunch of them… and all over the place… Admittedly I sort of like the way this thing looks, but my aesthetic judgement is questionable at best…


Weird looking thing…


Once again, the 1257 does not have the bite bar, but does have dynamic pans, which have morphed into triangles instead of quadrangles; and the pans move at angles along the axes (geometric term, not the chopping kind… wouldn’t want anyone to get hurt…) of the buttress rails, instead of the previous 1237-series chassis that had the dynamic pans moving parallel to each other and the longitudinal axis of the center main rail…


Anyway, even with the pans, the RTR weight came out to 98.6 grams... Joey farted again, and I added two small pieces of 0.015” thick brass sheet atop the two dynamic pans to get it to 100.2 grams…


A word of warning to anyone taking complete leave of their senses who might consider building a similarly designed chassis with rails running at all sorts of weird angles:

The more wires/rails running at different angles within a frame, the more critical (less error tolerance) those angles become, during the design and the build. That’s all I’ll say on the matter. Anyone desiring additional details, really think about it, and if the compunction is still there, ask me…


Test run:


Really good first test run for the 1257.2-Cc3; almost as good as the 1241-Cd3’s first outing. Ran the fastest first test run lap of any car ever. Handling is predictable and it is easy to drive. These cars tend to get better as the test runs progress, so tonight’s run for the 1257.2-Cc3 is very promising. The 1254.2-Cc3 also had its best outing thus far, and the 1241-Cd3 just keeps getting faster (and is making me think I need to build more “d” dimensioned chassis); a good test night all in all.


More designs and builds to come, consider yourselves warned; but that’s enough for new chassis builds for right now. Time to get the set-ups sorted out for the upcoming GRRR races at Fast Eddie’s Raceway on February 25.


Fun fun fun…


PSA: For all you poor suffering winter-types up North (which to me is anywhere north of the FL state line), just to let you know, the Florida State Fair starts tomorrow… I foresee massive quantities of meaningless calorific intake in my future…


More fun, fun, fun…


Rick / CMF3

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#65 Rick Moore

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Posted 26 February 2018 - 10:02 PM

Racing Update:


Alright all you competition freaks, here’s the latest lowdown from Team CMF from the GRRR races at Fast Eddie’s Raceway, Pinellas Park FL, Sunday February 25. Besides, it was a good excuse to take a weekend off from working at the hospital.


Chassis/car selection:


Stock Car, on the Oval:

I got some set-ups on the 1237-D2o (won both GRRR Stock Car races at Ed’s last year) and the 1241-D3o that had them handling the track and running faster than ever. But the 1244-D3o was even quicker and just as easy to drive. And this is despite the anecdotally accepted notion that these cars need to “weigh more” to handle and be drivable; the 1237-D3o and 1241-D3o are both around 125 grams, and I still had to tack on a little less than 1.0 gram of useless lead just to get the 1244-D3o to the 120-gram minimum. So, despite it being "too light" by some standards, the 1244-D3o would be my choice.


CanAm, on the Hillclimb:

Any one of six cars could have been run; the 1241-Cc3 (won last two GRRR CanAm races at Ed’s, and held the class TQ record, 4.538s, and lap total record, 295...), 1250-Cc3, 1241-Cd3, 1251-Cc3, 1254.2-Cc3, or 1257.2-Cc3. All have set-ups that can run in the sub-4.550 s/lap range. But I had found a set-up on the 1241-Cd3 (with a “7R” motor…) that could repeatedly hit laps in the sub-4.500 range, and was the only chassis/set-up to ever run sub-4.600 laps on Red and Black. So it would be the 1241-Cd3.


F1, on the Hillclimb:

No F1 races at the GRRR events at Ed’s last year, and the last F1 chassis I’d built, the A216-e3, was in June 2016, six months before the first of the 1241’s (which altered a lot in the 1237-series), until I built the A218-e3 in December 2017. The A216-e3 is still a quick car (finally found a good set-up for it), but, being quicker in the gutter lanes, I went with the much newer A218-e3.


Race Day!


First off, I need to do something about this driver I’ve got. He wasn’t doing so bad last year, but for this day of races he seemed to be bordering on brain-dead at times… probably all the junk food he happily ate during the FL State Fair clogging the arterial oxygen flow to his brain, and probably other vital organs and appendages… (and the FL Strawberry Festival starts Thursday… be lucky if he doesn’t eat himself to death…)


I’ll leave the full race report to Grant’s expert efforts over in the GRRR subforum. I will say it was a great turnout and fun day all around.


On the Team CMF front:


In Stock Cars, the 1244-D3o qualified second and finished second out of sixteen entries.


In Can Am, the 1241-Cd3 qualified second and finished second out of eighteen entries.


In F1, no qualifying, the A218-e3 finished third out of thirteen entries.


And the 1254.2-Cc3 is on vacation.


Not bad, really.


Some might say, “Oh, but they lost, they didn’t win”, but, in many cases those people are the personification of rectal sphincter leakage. If a better driver had been at the controller instead of the usual pinhead, like this guy Jeff whose name kept coming up, the cars would have done a lot better…


Who cares. The cars are competitive, even with the moron on the trigger. And this loser moron had a ton of fun. It’s always fun hanging out with all the other overgrown slot car geek kids.


Besides, just another excuse to build more chassis.


See ya ‘round, space cowboys.


Rick / CMF3

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#66 Tex


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Posted 26 February 2018 - 10:55 PM

Good job, Rick! You certainly put in the effort across the board.... design.... build...... test.... refine..... congratulations on your rewarded efforts!

Richard L. Hofer

Remember, two wrongs don't make a right... but three lefts do! Only you're a block over and a block behind.

#67 JBProducts


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Posted 13 March 2018 - 04:34 PM

I really enjoy racing you Rick, you do such a great job on those chassis !! 

Jeff Bonanno

#68 Rick Moore

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Posted 26 April 2018 - 06:38 AM



Scratchbuilding got put on hold while I finally got my hindquarters in gear and did some major renovations on Team CMF3 headquarters. Cleared, cleaned, rebuilt, reorganized, and even got me some new slot car boxes to schlep around… and long overdue… So, where was I before I was so rudely interrupted… Oh, yeah…


After some thought, or maybe it was just a bad case of gas, I’ve done another back-track…


The 1257.2-Cc3 made two changes to the 1254.2-Cc3: the redesigned front assembly, and the dimensional alteration of the relative lengths of the front and rear assemblies. The 1255 would have only changed the front assembly relative to the 1254…


A long time ago in this painfully unending thread I mentioned how I almost always regret skipping a step in the design sequence… well, guess what… the picture of an idiot in action…


There was enough of a difference between the handling characteristics of the 1254 and 1257 that warranted this back-track build. Or it seemed like enough of a difference that it got me thinking how the 1255 would compare to these two. Or, maybe it’s all just my imagination… or gas…


To reiterate, dimensionally the two measured lengths between the rear axle to the chassis framing’s central point of convergence, and then to the guide pivot for the chassis are, respectively:


1254 / 1255 / 1256:  R    2.875” – 2.00”      F

1257 / 1258:             R  2.4375” – 2.4375”  F


While the difference is only 7/16”, which doesn’t seem like much on its own, that is almost a tenth, or more precisely 9.14%, of the effective length (rear axle to guide pivot, 4.875”) of the chassis. That makes it seem a bit more significant…


In any case, I built the 1255 to fill the numerical and mental gap between the 1254 and the 1257. Besides, I really like the 1254 and the 1257; both are fast, and relatively easy to drive fast… but different… So even if the whole driving-thing I was “thinking” I was “seeing” turned out to be a case of synaptic dysfunction combined with colonic vapors, it wouldn’t bother me to have another one of these chassis in the slot car box…


Another one, just like the other one… the 1255.2-Cc3:

















Being as the majority of slot car enthusiasts have declining memory and optical acuity, here’s a side-by-side of the1255.2-Cc3 (left) and the 1257.2-Cc3 (right) for a better visual comparison:





Funny looking things… still make me laugh… It’s nice having them side-by-side and hand-in-hand affording me better opportunity to examine them physically, where before it was only conceptual, with the 1255 more “geometrically balanced” and the 1257 more “mathematically balanced”... in other words, the 1255 was designed from lines drawn to determine a common intersection, while the 1257 was lines drawn from a calculated intersection… Pull my finger…


With all the runny-bits on the 1255.2-Cc3 came out to an unadjusted RTR weight of 97.9 grams (which is 0.7 grams less than the 1257.2-Cc3’s unadjusted 98.6 RTR weight), which, due to the class 100-gram minimum whoop-dee-doo, necessitated the addition of a piece of lead to each of the dynamic pans, bringing the RTR weight to 100.1 grams. Joey farted again… A lot of gas being vented these days…


Test Time!


At this point in the series, all the CanAm class chassis/cars built before the 1241-Cc3, the 1237’s, 1238, 1239, 1240, and the 1245’s, have been put into non-active test status, still on call, but one step away from retirement, with the 1237-Cc2 and 1121-Cc4 as on-call GTC’s. With this current build that still leaves eight CA-class cars in active status for testing: the three 1241’s (-Cc3, -Cb3, and -Cd3), 1250-Cc3, 1251-Cc3, 1254-Cc3, 1257-Cc3, and this new 1255-Cc3.


This test outing was more about a comparison of these last three with fairly-even and fairly-new motors, with the other five just sorting through motors and set-ups. The goal was to decide if the next build would be the 1256 (ex 1255) or the 1258 (ex 1257)…


It is hard to describe the characteristic differences between the 1254 and the 1257; suffice it to say that the 1254 is more of a “point-and-click” driver, while the 1257 is more of a “roller”; I realize these are very esoteric descriptions, but some of you might get it…


The 1255-Cc3 was spot-on with its predicted (imagined, hoped for, better to be lucky than good…) handling characteristics, with a compromise of point-n-click punch (1254) and roller smoothness (1257). Even with the 1254’s power plant starting to kick in the afterburners (I’m guessing this HR will have a short life expectancy…), all three were very comparable. And all three are very good gutter lane cars, but it was on Red and Black that the 1255 started to show itself to be a little better all-around…


Sure, I’ll sit here and spreadsheet the numbers and all that silly crap, but…


Like drawing lines on a piece of paper just to see where they run together, sometimes you just have to go where it just seems like things should go… go with your gut feeling…


…which is probably just more gas…


Enough of this social media brouhaha, time to get back to finger-burning…




Rick / CMF3

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#69 Rick Moore

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Posted 09 May 2018 - 10:55 PM



After testing and comparing the 1255.2-Cc3 and the 1257.2-Cc3, I decided the next build would be a 1256.2-Cc3.


The 1256 is a minor variation on the 1255. Where the 1255 had the guide mount attached to the forward diverging main rails with short knee-brace rails, the 1256 has these knee-braces become an unattached structure between those forward diverging main rails. That’s it. Sort of…


Why? Pretty much on all chassis, especially those used on banked tracks, the guide tongue has a forward-upward angle. Here’s the long thought (or lack thereof) process: While keeping with the whole notion of trying to maximize downforce on the guide, the idea on the 1256 (or the 1257-dimensional version, the 1258) is to eliminate most of this chassis built-in front-upward angle to the guide mount; a certain degree of angle is still necessary to account for the forward-downward angle of the plane of the chassis due to the 0.050” rear clearance and the 0.015” front clearance, but that’s all; of course there is also any upward angle built into the guide itself, but this design was made regardless of that, keeping the guide tongue “flat” in running trim; the idea is to use the chassis dynamics to allow the guide to flex upward in this direction based upon running/track input forces, in the hopes of getting the chassis to “drive” the guide into the slot more, and effectively and relatively putting “more” of the guide into the slot… The short of it is, on the 1256 the guide tongue is flat.


As with the preceding 1255, this 1256 is a “.2” or 1241-variant, with “c” dimensions, and “3” or 0.032”-wire framed…


And as such, the 1256.2-Cc3:













Looks pretty much like the 1255, as it should. I’d apologize for the repetition, but that is the whole idea of design/build progressions; rinse, spit, repeat…


Here’s a side-by-side pic of front ends of the 1255.2-Cc3 (left) and the 1256.2-Cc3 (right) so you can see the difference in the framing behind (above in the pic) the guide mount.





And like the 1255.2-Cc3, the 1256.2-Cc3 in unadjusted RTR form came out well under the 100-g minimum la-dee-da at 97.0 grams, resulting once again in the addition of 3 grams of lead (…guttural noise, along with canine flatulence…) to the dynamic pans, 1.5-g each, to bring it up to 100.0 grams… Not sure why the 1256.2-Cc3 was 0.9 grams less than the 1255.2-Cc3; I thought it was going to be about the same or a tiny amount more… I keep thinking I forgot to put something on the chassis… hope not… anyway…


Test Run:


Since the 1255.2-Cc3 is a very stable platform, differentiating any differences displayed by the 1256.2-Cc3 was predicted to be somewhat difficult to discern… but still, that’s why we build ‘em and run ‘em…


And, boy, was I wrong. With a set of very equal test motors in the cars it was a lot easier to see what chassis was doing what. The “what” for the 1256.2-Cc3 turned out to be better than what I thought it might be. The 1257.2-Cc3 and the 1256.2-Cc3 were equally the fastest cars on Orange this evening, but the 1256 was smoother and easier to drive. On Black and Red the 1256.2-Cc3 outperformed everything, even running as fast on Red as it did on Orange, was better than the 1255.2-Cc3, which is an excellent gutter car, and even outran and was easier to drive than the 1241-Cd3 which has been consistently the best gutter car to date…


While I’m very happy with tonight’s results for the 1256.2-Cc3, it is still only the first run, in test trim. More testing is due, of course, as well as searching for that ideal race set-up. I don’t put too much into just the first run, but I am optimistic for the 1256 design. In fact, after running the 1241-Cd3 and 1256.2-Cc3 on the gutter lanes, I got to thinking I should build another 1256, but this time with “d” dimensions…


Scratchbuilding… it’s a disease…


Rick / CMF3


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#70 Rick Moore

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Posted 30 May 2018 - 10:22 PM



If you go back to the 1241-Cd3 post (on second thought, you may not want to torture yourself like that…) you’ll see why I toyed around with the 3.75”/4.875”/1.125” dimensioned chassis. Since then testing has shown the “d” dimensioned 1241-Cd3 to be one very good chassis. That sort of prompted a desire, if not necessity, to build more “d” cars… the question was where to start… especially since I had a string of designs coming of late and had to keep them at “c” dimensions so I was comparing apples to apples… or maybe that would be more like McIntosh to McIntosh, without throwing in a Winesap…


After the last build and subsequent testing, I opted for the 1256.2 design/version, giving the 1256.2-Cd3:













The 1256.2-Cd3 looks, and is, exactly like the 1256.2-Cc3 except for the shorter wheelbase that puts the front wheel wells 0.125” more towards the rear of the chassis, resulting in the front wings being longer and the “side pans” being shorter accordingly.


Here’s the side-by-side for visual comparison, the 1256.2-Cc3 left, the 1256.2-Cd3 right:





In its as-built unadjusted RTR form the 1256.2-Cd3 came out to 98.9 grams… lead added to dynamic pans, annoyance, dog farts, final weight 100.2 grams.


And for optical amusement, a pic of the final RTR chassis/car:







Wednesday evening, Ed’s, Hillclimb, comparing the 1256.2-Cd3 with the 1256.2-Cc3 and 1241-Cd3, along with more test runs for the other seven CanAm’s…


Good car. The 1256.2-Cd3 is to the 1256.2-Cc3 what the 1241-Cd3 is to the 1241-Cc3, and all of those are really good cars. All three of the previous chassis/cars are great gutter lane cars, with the 1241-Cd3 the best and fastest gutter lane car to date, with the 1256.2-Cc3 only a hundredth or less off its pace… until tonight… the 1256.2-Cd3 easily set new fast lap records for any CanAm car of mine on both Red and Black… and ran the fastest first test session lap(s) on Orange…


Okay… I can live with that… Good car… And Bob’s your uncle…


Keep in mind both the 1241-Cd3 and the 1256.2-Cd3 have longitudinal dimensions that go counter to conventional wisdom or accepted norms for what should “work best” for things like wheelbase and guide lead… who’d o’ thunk…


You just never really know till you build ‘em… really…


More testing… more building…. more fun…


Rick / CMF3


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#71 Rick Moore

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Posted 14 June 2018 - 09:46 AM



Due to numerous persons being maimed and a few deaths, it was time to build another F1 chassis…


Nah. Not in reality... but who cares about that…


It was time to build a new F1 frame based on what I’d learned on the A218-e3, and based on the 1256 CanAm chassis design to see the applicability to other class frames, in this case an F1.


On the A218-e3 the front chassis extensions (tines, forks, prongs, harpoons, harbingers of the end of Western civilization, I don’t care what you call them…) that support the body front wings, despite being wider, taller, and stronger than previous versions on other F1 frames I’ve built over the last six years or more (…and ignoring “points” of contention… if concerned, please see “Note” later in this post…), were found to need a little more structural reinforcing, so a redesign in this area was incorporated early on in the design of the A219 and A220 chassis. To this end a set of 2x2 0.032” wires are incorporated between the fronts of the extensions, allowing this “bumper” to keep the extensions from skewing with regard to each other, as well as acting as a guard for the guide, and allowing more of the front of the McLaren M7 body to rest on the chassis front. This bumper is mounted in 1/16” brass tubes to make it removable, allowing easier access to the guide braid, and making it more easily replaceable if damaged.


I kept this one with the “e” dimensions, and “3” framed in 0.032” wire, so…


The A220.2-e3:













The unadjusted RTR weight came out to 98.2 grams, below the 100-gram oinker, even with all the brass pans added in all the nooks and crannies on this thing. Speaking of pans, five of the brass pans are 0.025” brass and dynamic, and the other three are 0.032” brass and static. Anyway, dog farts, lead added, final RTR weight 100.2 grams.





Now, to the matter of whether this chassis, or any of my other F1 chassis I’ve built and raced over the last six-plus years, might now be “…deemed potentially to be unsafe…” by a race/tech director that has that particular car in his hands at that particular time… In all honesty, I don’t care. I just won’t bother to race it. No big deal. Done. Comments in this regard to be considered accordingly…



Test Run:


No animals were harmed in the testing of these slot cars. An abbreviated first test session, as I was doing some major motor/set-up tests on the ten CanAm cars; I definitely have to try to fit in more runs. Anyway, the A220.2-e3 cranked out first test run laps better than any F1 prior, and was only six hundredths off the pace of the A218-e3. I don’t think I got the guide depth set right, among other things, so with due consideration the A220.2-e3 looks promising. Also, a total brain-fart by the test driver gave the A220 an unintended wall-shot, and the front extensions and bumper came out unscathed and un-skewed, faring much better than the A218 in similar hits; while this was not a planned test of the A220’s front redesign, it was needed information that, while warranted, would have been obtained sooner or later… just wished it’d been later… idiot...


Toy cars. The fun never ends…


Rick / CMF3


#72 Danny Zona

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Posted 14 June 2018 - 10:37 AM

I love watching Rick test. He goes hard in the paint.

I even got to try one of his can-ams last night.They are amazing works of art. So cool.
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Test, test, test and go test some more.
You're never fast enough!!! 💯

Preparation leads to separation.

Success is never owned but rented and rent is due everyday.


#73 Rick Moore

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Posted 24 June 2018 - 09:36 PM

Racing Update:


All work and no play makes Jack a dull boy…


It was time to take off a weekend from working at the hospital once again, for a generally much needed respite, and so I could attend the GRRR series races held at Fast Eddie’s Slot Car Raceway in Pinellas Park FL on Sunday June 24... today.


Chassis / Car Selection:


Stock Cars on the Tri-Oval: There was no doubt I’d run the 1244-D3o again, with a better/faster set-up than I had previously.


CanAm on the Hillclimb: I was planning to run the 1241-Cd3 again as well, changed my mind this morning to go with the 1254.2-Cc3 instead; the 1254 is one of those chassis that just seems to get better with testing, and I had stumbled onto a really good set-up for it during the test runs; that, and it appears to handle changing track conditions rather well (this needs more observation and data).


 F1 on the Hillclimb: I was going to run the A218-e3 again as well, with a very good set-up, but again changed horses in midstream and went with the new (and few test laps) A220.2-e3 instead.


Both final CanAm and F1 choices were based upon the “Why Not” principle…




Stock Cars, 15 entries: The 1244-D3o TQ’ed for Stock Car with a new lap record. Drove like crap, got down too many laps, came back to pull out third.


CanAm, 14 entries: Qualified third (the two faster were the first official qualifying laps below 4.5, a 4.48, and a staggering 4.41 by that Jeff guy again). The 1254.2-Cc3 ran steady across all lanes, including the gutters, and despite the motor taking a dump about halfway through the last heat was able to hold on for the win.


F1, 6 entries; no qualifying. I really had no feel for the A220.2-e3, so this was a learning experience as much as anything; learned a lot; somehow managed to bring it home for the win while I was at it (and no one was maimed or killed…).


Sometimes it’s better to be lucky than good.


Other Stuff:


Check the GRRR sub-forum for Grant’s official race report.


Thanks to Ed, Grant, super-volunteer turn-marshal Mike, all the slot car geeks who came, and to blind luck for getting me home through the flooded streets of South Tampa…


The inaugural Southern Retro Rumble will be held at Fast Eddie’s Raceway on September 14 & 15:




This is already shaping up to be some crazy-fast races. Hope y’all can make it down for the fun!


See ya, space cowboys.


Rick / CMF3

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#74 Rick Moore

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Posted 19 July 2018 - 08:53 AM



This is one of those cases in the course of this 1237-series of designs and builds where it was necessary to reevaluate what was being observed and to some extent learned. Where the 1254 design had originally been back-designed to make a more continuous progression to the 1255 and subsequent designs, and built to ensure there wasn’t a gap in the chassis builds, the cumulative testing and displayed performance of the 1254.2-Cc3 begged for further investigation… or something like that…


Not long after building the 1254.2-Cc3 (while it was on vacation) I was considering building a “d” dimensioned version, but instead pushed ahead with the 1257, 1255, and 1256 builds. But now, after opting at the last-minute to race the 1254.2-Cc3 instead of the 1241-Cd3 at the last GRRR races at Fast Eddie’s and then gaining a better appreciation for the 1254’s performance, which was every bit as good as the “c” and “d” 1241’s (possibly better, with the motor giving it up about a minute into the last heat, but holding on for the win), I figured it was definitely time, and worth the time, to build a “d” dimensioned 1254.2, especially since this would give me “c” and “d” versions of the 1241, the 1256, and now the 1254. That, and I saw no harm in having an extra 1254 in the stable of CanAm cars. Plus I’m getting a little better at building these multi-angle frames… anyway…


For those keeping track (you poor suffering souls), this is the twentieth CanAm chassis design/build in the 1237-series progression. When put in that context, it makes the misery even more all-consuming. Abandon all faith ye who enter here…


The 1254.2-Cd3:













Looks just like the other one, repetitive, yadda yadda. One thing not noted before is that the 1254’s have a V-shaped 0.055” wire acting as a “spine” above the 0.032” wire frame at the forward “V’ of the motor box; this spine wire is not present on any of the subsequent builds, the 1257, 1255, and 1256’s, as at the time of their construction I deemed it not necessary; this spine wire is now a matter I am also revisiting and reconsidering...


The 1254.2-Cd3 came out to 99.8 grams with all the runny bits. Little dog squeaker fart. Stupid 0.2 grams…


As I noted before, the “old” 1254.2-Cc3 was originally built merely as a “link” in the design/build progression between the 1241 and the 1255/etc; it only had to be “as good as” the 1241-Cc3 to green light the next builds in the series. It was, and that would have been that… however… Even though 1254.2-Cc3 was treated more as an afterthought in the grand scheme of building and testing, subsequent set-ups and test runs would show the 1254.2-Cc3 to be better than the 1241-Cc3 on most occasions, and on many as good as the 1241-Cd3 (hence how it went from being my “practice car” to my “race car” the last time out). The “point-and-click” characteristics of the 1254.2-Cc3 took a little adaptation on my part, but appears to be worth it, as the 1254 will launch out of the turns quicker than anything else. So while it was not originally planned to have this much attention, its continued testing, as well as my own practice, became requisite.


The question with the 1254.2-Cd3 will be if and how it displays similar characteristics. It also needs to be tested against the 1241-Cd3, and any of the host of others as may seem appropriate and/or applicable, because...


Test runs:


Well, not the first. I held off on this one to get a second set of runs.


Here’s what I’ve been finding out during my test runs of late. On any given evening, along with the three 1241’s, any of the latest batch o’ builds, the 1254, 1255, 1256’s, and 1257, can step up with the set-up to be not just a top performer on that day, but THE top performer. And I think there just might be “something” in all this, but more testing, observation, and data is required… or it could just be my imagination... who knows… who cares… Anyway, after last week I decided I needed another set of test runs.


For instance, last week:


The 1255.2-Cc3 came out of nowhere to turn some really good lap times. Meanwhile I’d forgotten I hadn’t changed the motor on the 1254.2-Cc3 since the race, ran some laps anyway, they were slow, and then, ZOOM, all of a sudden it was back as fast as ever… probably just some of that "inconsistent" motor stuff people have conniptions about… it is kind of weird though… Anyway, after all that it came down to the 1241-Cd3, the 1254.2-Cc3, the new 1254.2-Cd3, and the chassis du jour 1255.2-Cc3. On Orange all four ran within 0.01s of each other. On Black the 1255 set a great time just ahead of the 1241-d, but the new 1254-d clobbered it. On Red it was the 1241-d just nipping the 1255, the 1254-c hot on their heels, and the new 1254-d took a dump in the Donut… almost a tenth off… Hunh?


Out of the box the 1254.2-Cd3 looked stable and super-fast through the turns, all the turns, as good if not better than the 1241-d and 1254-c… except the Donut on Red; it would absolutely fly on Red, until the Donut… Something wasn’t right here, and time was running out on this Wednesday evening, so…


Last night I had some set up changes on the 1254.2-Cd3, and while improved, it still had some push about two-thirds up the donut on Red. Runs pretty good everywhere else still; definitely has potential. Obviously there is something, or, more likely, are some things, in the set-up I’m missing, so, like the preceding 1254, this will move to a back-burner to simmer while I cook up the next item on the menu...


Sidebar: As for the reconsideration of the V-shaped 0.055” spine wire used on the 1254’s, I added one to the 1256.2-Cd3 for testing. More so after considering track variables, first tests were inconclusive, so there may or may not be anything to it… more testing…


The slot car geek mantra: Set-up, test, set-up, test, set-up, test, set-up, test…


Keep the iron hot and the mind open… and, most importantly, have some fun…


Rick / CMF3


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#75 Rick Moore

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Posted 25 October 2018 - 08:40 AM

CMF3 1262-Series


The nightmare continues…


The 1262-Series of chassis designs and builds represents enough of a departure from the 1237-Series that they could warrant their own classification as a separate series, but, like the 1229’s in the 1219-Series, in actuality they are a sub-series of the 1237’s retaining enough of those design elements to allow their inclusion in this thread… that, and I didn’t feel like starting another thread…


The similarities between the 1237-type chassis and the 1262-type are: the rear assemblies will still be either based on the 1237 or the 1254 designs; the side pans with front wheel wells connecting to the front spanner assembly with guide mount also remain intrinsically the same.


The difference is everything in between. Where the 1237-series designs were based on a single solid center main rail or central main rail assembly flanked by rear articulated buttress rails, the 1262 series uses a central main rail with flanking medial and lateral buttress rails (for a total of five “rails”). One way to envision the rails would be, if looking from the rear, the rails form a “VIV”, with the “I” being the center main rail and the “V’s” as the medial and lateral buttress rails. With a total of six connection points to the front and rear assemblies (three front, three rear) this rail configuration on the 1262-series allows for a relatively large number of possible attachment combinations of these five rails to the front and rear assemblies, either “solid” or “articulated”, symmetric or asymmetric. With further design modifications as many as ten rail connection points could be possible. Additionally, the possibility exists for any or all of the articulations incorporated within any given chassis variation to be outfitted with a screw housing that will effectively lock/unlock that articulation... But not yet… The intent of these various solid/articulated configurations in effect should allow any given chassis to structurally mimic various chassis design types...


And, collective groans noted, all this has resulted in the CMF3 alphanumeric identifier for these chassis becoming even more convoluted and esoteric.


So, some might ask, why bother? Sure, we’re all always looking for that “magic” chassis that works on all tracks in all conditions, but deep-down we’re all pretty sure it doesn’t exist, while at the same time it doesn’t really stop us, does it? One of those dualisms of slot cars. Whenever I am faced with the whole philosophical aspect of any subject matter I tend to say screw it, it doesn’t matter, and proceed head-down and careening. Cheap thrills. So, just as valid is to ask, why not?


And “why not” was predicated on some conversations with other slot car geeks, and looking at the variety of chassis used at various venues, where more questions arise than answers (unless you’re one of the “Know-It-All’s”, in which case you’re not reading this, or at most probably quit in the third paragraph…).


It took me a while to sort through all the conceptual possibilities, come up with a working design to cover them, and figure out the multiple construction methods and sequences that would work in each scenario. Piece of pie. Easy as cake. I need to get a life… or some dessert…


With so many possibilities, the real question that needed to be answered was: Where to start?

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