175 replies to this topic

[Rick Moore]

A216-e2

 

Time to move on to the next chassis in the F1 progression.

 

After much (way too much) convoluted contemplation, I made two changes in this design/build progression step… Let’s see if I regret it…

 

The big change, the “planned” one, on the A216 from the A214 is the incorporation of Front Axle Rails (FAR’s). Unlike the 1239 et al (with each left and right FAR having medial and lateral rails flanking each buttress rail), the FAR’s on the A216 are 3x wire single rails only lateral to the buttress rails (the buttress rails positioned more medial to allow location for the FAR’s), and the left and right FAR’s are connected with a spanning rail. This adaptation was done largely due to the space considerations of the narrower F1 chassis. This also allowed the continued inclusion of dynamic pans, which on the A216 are 0.032” brass plate (instead of the A214’s 0.010” brass sheet backed with 0.032” wire).

 

The second “unplanned” change was, while keeping the wheelbase the same (3.875”), to increase the RAX-GPC and guide lead by 0.125” (5.00” and 1.125” respectively), hence the “e” in the chassis designation. There are numerous reasons I’ve been wanting to try this on a F1 chassis with FAR’s, but the leap in the progression was spurred on by some mathematical guess-timations that were telling me the RTR A216-e2 might weigh as much as 105 grams, which got me thinking a 0.032” wire framed version (A216-e3) just might be possible… that’s a big “might”, but this was worth the jump to investigate that possibility that I previously I thought would absolutely not be possible… So much for absolutes…

 

Anyway, the A216-e2 looks like this:

 

 

 

 

 

 

 

Now for the big question; envelope, please: The 0.039” wire framed A216-e2 RTR car came out to 103.3 grams.

 

I’m guessing a 0.032” wire framed A216-e3 might be in the 96 – 98 gram range… or about the same as the A214-c2… This just might be a real possibility…

 

But first things first…

 

Test run:

 

Simply put, the A216-e2 is every bit as good as the excellent A214-c2, with the exception that it is easier to drive… which I found hard to imagine… but there it was. The lap times are very comparable, with the A216 only about 0.01s quicker (despite having a motor I never thought was worth a flying… uh… rhymes with lap…), but able to turn fast laps even easier and more consistently than the A214… seems weird saying that. And that was “out of the box”. There will be more testing and tuning, certainly.

 

Hmmmmmm… 0.032” wire…

 

Rick / CMF3

[Rick Moore]

A216-e3

 

As warned, I went ahead and doodled up and built my first all 0.032” wire framed retro F1 chassis.

 

Some of the necessary changes moving from the 0.039” framed A216-e2 to the 0.032” framed A216-e3:

 

Central main rail 8x wire to 10x wire wide;

Buttress rails 4x wire to 5x wire wide;

Front axle rails and motor box rails 3x wire to 4x wire wide;

Dynamic pans 0.032” to 0.025” thick brass plate.

 

The A216-e3 came out like this:

 

 

 

 

 

 

 

The result though is that the two A216 chassis look almost identical. Some pics of the two, 0.039" A216-e2 left, 0.032" A216-e3 right:

 

 

 

 

I had guess-timated it would be about 96 – 98 grams, and the A216-e3 RTR car came out to 96.9 grams. Anticipating this, during the build I trimmed up some lead pieces to fit on the dynamic pans, and after adding the minimum compliment of these (can be seen with Blue tape backing in above pic) the final RTR weight came to 100.3 grams. (I’ve never been a big fan of minimum weight rules in scratchbuilding classes, especially when the F1 class has the same minimum weight as the CanAm class, but it is what it is…)

 

Test run: Got over to Fast Eddie’s Raceway yesterday. I compared the 0.032” wire framed A216-e3 versus the 0.039” wire framed A216-e2 and A214-c2. All ran best laps within 0.05 s of each other. As was the last time the A216-e2 ran slightly quicker than the A214-c2, but the new A216-e3 was the quickest, and the easiest to drive of all three. I am definitely looking forward to more test runs.

 

That’ll probably hold me for F1 builds for a while. I’ve got two retro 4.5” Stock Car chassis and another CanAm chassis (just what I need, another CanAm chassis…) in the works, a couple of fun projects on the O-2-It list, plus the next major adaptations to the 1237-series CanAm’s have already found their way into the design and planning stages… Not sure which comes next, but you can consider yourselves forewarned…

 

Rick / CMF3

[Rick Moore]

Update: Racing!

 

“How do the times run with these unique cars compare to the more standard *Retro* builds?”

 

“Rick, have you had the opportunity to see how competitive your latest cars are against the rest of the Florida retro fields?”

 

Okay. For all you competition oriented types out there, I finally made it to one of the GRRR retro races yesterday, racing CanAm and F1. I had to take the weekend off from work to do it, but I was overdue for some time off anyway. Besides, a bad day of slot cars is better than a good day of work. Well worth it.

 

First things first, I need to make some excuses. This was my first racing in over two years, so I presumed I’d be a bit rusty. When I say my driving ability has gone from mediocre to abysmal, that is an honest assessment. My hand-eye time ain’t what it used to be, the brain connecting them being suspect. That same brain seems to get – SQUIRREL !!! – what was I talking about? Overly conservative and inconsistent was my assessment, and a bad combination; besides testing laps, I obviously need to just run a lot more practice laps…

 

Also, due to that lack of racing, I’ve yet to make any monetary commitment to purchasing any new Retro Hawks to find any “magic bullet” motors (I have a few old ones that are at best “okay”, but mostly “pretty anemic”), instead just continuing to use my old, and in some cases very old, PS Pup Dogs… at least till the end of this year… It actually got sort of funny as the Hawk cars would roll by my Dog with every track call.

 

Plus, if I remember correctly about this slot car racing thing, I think I’m supposed to say everyone who beats me is cheating, right? Or, is it that the rules are rigged? Or both? Probably need to up my curmudgeon factor if I want to do this slot car thing seriously…

 

(And all apologies to those who were disappointed Joey didn’t come along. Like me, he’s old and doesn’t get around as well as he used to.)

 

What may come as a surprise is that I ran the 1237-Cc2 chassis for my CanAm car. At least, it came as somewhat of a surprise to me. That’s the first chassis way back in the beginning of this rather lengthy thread. Rather than relegating it to “has-been” status, I kept toying around with it to see what made it tick, and, largely by blind luck, came on a set-up that was way better than I expected. Same goes for the 1237-Cc3 (the 0.032” wire framed version). Performance-wise they caught up to the 1239-Cc3, which I had largely left alone. So last week I said what-the-heck and concentrated on the 1237’s as my go-to chassis for this event. Mostly this meant sticking some new Ti-22 bodies on them; the TrueScale McKees I’d been using were pretty beat up from testing, and my inventory is largely gone while Victor is still on his much needed hiatus.

 

For the F1’s it came down to a toss-up between the A214-c2 and the A216-e3, with almost identical lap times of late, despite their inherently different handling characteristics (they prefer different tires). The A216-e3 would get the nod for its better ability to handle the nuances of my current driving ability (derogatory characterization warranted).

 

There were twenty CanAm entries, three mains; qualifying was only a 30 second session per racer, but somehow I managed second fastest; in the A Main I’d finish fourth. Ten entries for F1, a two sit-out main, no qualifying (used CanAm finish for lane choice), and I wound up fifth. In both classes I can say I was in no way disappointed with the cars. Plus, it was a lot of fun!

 

So, yeah, the weird wire chassis can still compete.

 

That guy driving them though…

 

 

Rick / CMF3    

[Rick Moore]

1245-Cc2

 

The satisfaction I have now for the performance of the original 1237 design has encouraged me to jump forward to build a new design in this series, the 1245. Like the original 1237-Cc2, I’ve opted to build the first of the new 1245 design using 0.039” wire for the framing and using the same dimensions, making this the 1245-Cc2. Like the first 1237, this first 1245 is more a proof of concept design and build; from here I’ll have a better idea of the chassis characteristics, and what I can get away with trying to build it in 0.032” wire, as well as further design modifications...

 

The 1245 is largely the same layout of the 1237 with one major adaptation. The buttress rails are now articulated at the front as well as the rear, with each supported structurally by rails extending from the front apex of the rear motor box assembly where it connects to the central main rail. The result is something that looks like an “asterisk”, or:

 

*

The thought behind this is to have a more direct line of force from either front wheel (with front axle uprights above the buttress rails) to the opposite side’s rear tire. In other words, upward force applied to the outside front tire when cornering will transfer downward force to the inside rear tire. It seemed like an idea that was worth trying to see if it had any effect at all, and, if so, how it affected the overall chassis dynamic and handling.

 

Some pics:

 

 

 

 

 

 

 

 

 

Even I have to say, that is one weird looking chassis.

 

Unlike the 1237’s dynamic pans flanking the center main rail, on the 1245 the much smaller pans (only flanking the main rail at the forward portion just behind the guide tongue mount) are semi-static and not soldered directly to front spanner assembly. These were added to allow the addition of small amounts of lead ballast to the forward half of the chassis, since all guess-timations showed the car would probably end up about 96-98 grams… Aesthetically they almost look like they belong there.

 

The bite-bar used on the 1237 was not included on the 1245, at least on this 0.039” wire frame build. Unless the track is stuck after being freshly glued, I’ve never had to really use the 1237-Cc2’s bite bar much, the screw setting being set at minimal contact. I can always add the bite-bar to this 1245-Cc2 if I find it to be warranted, or incorporate it on any 0.032” wire framed versions of the 1245 and subsequent designs/builds where it might be more advantageous.

 

The car balances right at the center of the “asterisk” where all the rails meet; it is better to be lucky than good. The RTR mass came to 97.5 grams. Initial testing would be at this weight.

 

Speaking of initial testing, though the car was ready last week, it was also raining a bit here, so I didn’t get over to Fast Eddie’s Raceway until this evening. (Discretion being the better part of valor, with last week’s tropical storm washout, locals know it is best to just stay home and off the roads, which quickly flood with every heavy rain, much less…)

 

Of course, for handling characteristics testing purposes the baseline for the 1245 is the 1237; as it turned out, it will also be the performance baseline in subsequent testing. Honestly I had so much fun figuring out and building the 1245 chassis I really didn’t care if it turned out to be a piece of poo…

 

First thing I noticed was the motor in the 1245 was a bit flat on the top end. Regardless, the 1245-Cc2 was outright quicker than the 1237-Cc2 (and the 1237-Cc3 and 1239-Cc3, all of which have very equal motors). It was even more noticeable as I moved toward the gutter lanes. It easily carried more speed in the turns, making up for any deficiency it showed in the straights. It was also unaffected by the addition of two small lead weights to the front semi-static pans, bringing it up to the minimum weight thing.

 

Considering how much I like the 1237-Cc2 (which I’ve been testing for some time now and ran in the last GRRR CanAm race; I’m also now getting additional input from Ed Hoffman who has the second 1237-Cc2 I built), I can say I’m satisfied with the initial test of this 1245 chassis. Might be something to this design after all… weird looking and all. More testing will follow.

 

Rick / CMF3

[Rick Moore]

Update: Racing (Part 2) !

 

As for my part a last installment for comparison purposes of the competitiveness of the 1237-series chassis, I took another weekend off from work and got to the GRRR races at Fast Eddie’s Slot Car Raceway in Pinellas Park yesterday. The initial observation is that slot car racing at a great raceway with a great bunch of fellow slot car geeks beats the living “excrement” out of working (and I actually like my job). Anything after that was just the proverbial icing on the cake… well, actually, donuts; but I had already brought a café con leche and some Cuban toast… life is good…

 

Since the races in August, I made a major monetary expenditure and bought a boat load of Retro Hawks. All-in-all I can state that my observations to date as to the percentage of “race worthy” motors versus the "middling-mediocre" to "outright-junk" motors continues to be less than favorable, and I’ll leave it at that, omitting any derogatory comments. But it had to be done…

 

And since the last race I built that 0.039” wire framed 1245-Cc2 chassis, and with testing had decided this was going to be the car I would run in the CanAm race. I really like this chassis a lot. The evening before Sunday's races I went over to the raceway and had it set up and ready to go…

 

And gave the 1245-Cc2 a few laps that morning to make sure. Then, for some practice laps, I proceeded to run a few laps with the back-up 0.032” wire framed 1237-Cc3… at which point I opted to change horses in midstream and run the 1237-Cc3 instead of the 1245-Cc2. It just “felt” like it was “smoother”, or more “fluid”, or whatever. Call it “a hunch”, I don’t know, it just seemed right at that moment, and without any further thought I just went for it. (This was not dissimilar from how I came to run the 0.039” wire framed 1237-Cc2 the last time out, though in that case with more time before the race).

 

In CanAm qualifying (I was last to qualify) the 1237-Cc3 ran its fastest lap ever on the Hillclimb, its first sub-4.7, and that was on the third lap… so I stopped… good for second fastest in qualifying of 14 entries. Went on to finish second in the A Main, the car performing very nicely on all lanes. (And my driving was better than the last time out, though there were still some “sketchy” moments, what we all call brain-far…) Also, Ed Hoffman qualified his 1237-Cc2 third fastest, and finished fourth in the race.

 

In F1 I once again ran the 0.032” wire framed A216-e3 and with the same P-Dog motor as last time. It’s just a good combo, and I couldn’t find a better set up with the R-Hawks in the A214, A215, and A216’s. Qualified third and finished in second place out of ten entries.

 

So, yeah, the weird wire chassis can still be competitive. They’re definitely fun.

 

(For the Stock Car class, I had decided to not run the 1237-D2o, instead running one of the two stocker chassis I was given by Marty Stanley the last time I saw him before he died earlier this year; It just seemed like the right thing to do... On the Oval at Fast Ed’s yesterday, eleven entries, qualified third, finished fourth. Thanks Marty!)

 

After the races yesterday, TonyP asked, “So, I guess we won’t see you again until next year?”

 

Yep. That’s pretty much it for me. I’m trying to get one more weekend off this year, strictly for R&R, right before I have to work the Christmas and New Year’s weekends… Urf…

 

…Unless they start holding races on Tuesdays, Wednesdays or Thursdays…

 

Great seeing everyone again! And, everybody, make sure you’re having fun!

 

Rick / CMF3

[Rick Moore]

1245-Cc3

 

At this point, with testing, and now two races, I have a better appreciation and understanding for the characteristics of the 1237-Cc2 (0.039” wire framed), and the 1237-Cc3 (0.032” wire framed). The 1245-Cc2 (0.039” wire framed) was the chassis I had originally intended to race the last time out, but the last minute opting for the 0.032” 1237-Cc3 got me thinking it would be beneficial to build a 1245 design framed out in 0.032” wire.

 

The problem was the 1245-Cc2 had barely made the minimum weight for CanAm cars, and I had guessed the chassis framed out in 0.032” wire would make a car about 8-or-so grams lighter. At this time I was not ready to reintroduce the adjustable bite bar to the 1245 design/build (which is actually the “1246”), so that mass could not be counted on to offset the loss of overall mass. Instead, I would have to incorporate semi-static pans to fill the four central spaces along the 1245’s central main rail and buttress support rails.

 

So here are the pics of the 1245-Cc3:

 

 

 

 

 

 

 

 

With the exception of the pans, the 1245-Cc3 looks the same as the 1245-Cc2. Still looks pretty freaky.

 

The four semi-static pans are 0.032” brass plate suspended from the chassis framing with 0.024” wire; they added 8.4 grams of mass to the chassis. The final RTR weight came out to 101.9 grams, but this was with a R-Hawk this time (trying to get ready for the coming rule change), instead of the P-Dog’s I had been using, which adds about 1.7 grams (so based on my “old” WAG-math, it would have been just over 100 grams… gotta remember to factor in the extra motor mass next time…).

 

Test time:

 

Back to Fast Eddie’s Raceway and on to the Hillclimb. The base line for this 1245-Cc3 is, of course, the 1245-Cc2; but since they were also my last “race” cars, and also exhibit the nuances between a 0.039” frame and a 0.032” frame, the 1237-Cc2 and 1237-Cc3 would also be used for comparison. These latter three were still in “race trim” from last month’s GRRR event, so it would be a tough comparison. The 1245-Cc3 also just got “another” R-Hawk motor, while the others still had their “race” motors. Still, after a minor addition of 0.005” spacing on the guide depth to the 1245-Cc3, it was able to run within 0.01s of the lap times of the 1245-Cc2 and 1237-Cc2, and 0.04s of the 1237-Cc3 (all three of which ran faster than my qualifying time at the last race). The handling was what I’d imagined, so overall I’m more than happy with this first test run. Additional fine tuning and tweaks should easily make it the “fourth” in my armada. (And I need to backtrack and work on the 1238, 1239 and 1240, which have largely gone neglected the last few months.)

 

(Side note: The A216-e3 had more damage than I was aware from the F1 GRRR race; second place was definitely a case of luck. As a matter of tuning and testing last night, I ran the A214-c2, still using a P-Dog, and with little effort it ran 0.09s faster than the A216-e3 qualified for the GRRR race, so if proper repairs are not manageable I may have to build a second A216-e3…)

 

Well, that was fun.

 

Rick / CMF3

[Matt Sheldon]

It takes a lot of coffee for me to stay focused on what you have going on there, Rick!

 

Amazing stuff as always and love the narration.

[SpeedyNH]

Rick, as an old chassis builder, that's some mighty impressive cutting, bending, aligning and soldering.

speedy

[Rick Moore]

1241-Cc3

 

After a break to take care of some of that pesky “life” stuff, it was time to get back to this slot car chassis designing and building fun stuff.

 

When I made the skip to the 1245’s, there was still a pending build in the progression, specifically the 1241, so I had to tie up this loose end. In actuality this was not back-tracking, as elements of the 1241 design were taking on aspects of subsequent designs, as well as applying some component alterations based on observations of the preceding chassis. The result of this pondering procrastination would be the 1241’s final design being quite different than the original draft. Since there was no possibility of returning to that original design, there was no need to re-designate the latest version with a different alpha-numeric moniker. So while it is a 1241, it is definitely not what the 1241 started out as… more like “1241 version 2.0”…

 

In a nutshell, the 1241 retains the 1237’s singular solid central main rail with flanking articulated buttress rails, but adding front axle rails; however, unlike the 1239 and 1240 that have twin front axle rails flanking each left and right buttress rail both laterally and medially, the 1241 only has a single front axle rail on each side flanking each buttress rail on the medial side only; also the front axle rails, independent on the 1239 and 1240, on the 1241 are connected to each other by a “torsion bar”, that also acts as the contact point for the variable spring wires (VSW) located on the buttress rails; the result on these revisions of the 1241 is, for the first time in one of my designs, this places the VSW’s lateral to the front axle rails and front axle uprights (as opposed to medial on the 1225-1233’s, and neutral on the 1239-1240).

 

Having built the 1237’s, as well as the 1245’s, in both 0.039” wire framing (“2”) and 0.032” wire framing (“3”), I saw no need to build the 1241 in 0.039”, so 0.032” wire it would be.

 

And for this first 1241 build I’m keeping with the standard “c” dimensions (3.875”/4.875”/1.00”). At some point I want to try one of these chassis with “b” dimensions (3.75”/4.75”/1.00”) and/or “d” dimensions (3.75”/4.875”.1.125”), after the success of the F1 A216’s “e” dimensions (3.875”/5.00”/1.125”), and then doing some retesting of the old 1229-Cc2, 1229-Cb2 and 1229-Cd2 on the Hillclimb track at Fast Eddie’s.

 

So, whether in consideration of or despite of all that, here’s the 1241-Cc3:

 

 

 

 

 

 

 

 

 

The adjustable bite bar of the 1237-series is still a component on the 1241 (the thinking being this will be a desired component if the 1237-1241’s ever wind up on a swoopy King, even though there are no King tracks in Floridada, swoopy or otherwise…). Also, the 1237-1238’s dynamic pans between the central main rail and the front axle / buttress rails are incorporated, with the exception on the 1241 these pans fill the entire space; on the 1241 the pans are 2x wide 0.024” wire as a perimeter with 0.010” brass sheet as filler (and if you’re wondering why I usually don’t just cut some sheet brass to make pans, there are three reasons: 1) they weigh a lot less; 2) though more labor intensive, I like the way they look “framed”; 3) because I can).

 

Also on the 1241 the VSW’s have been changed, from the 3x wide 0.032” wire on the 1239 and 1240, to 4x wide 0.024” wire. This is largely an experiment; could be good, could be bad, or even could be both; if it works I can easily change the 1239 and 1240 to 0.024” VSW’s, and if it doesn’t I can just as easily change the 1241 to 0.032” VSW’s.

 

The 1241-Cc3 would also immediately have a “sissy bar” added to the chassis (see “Testing Update”).

 

The mass of the RTR car came out to 101.0 grams. Not bad.

 

As a side note, I finally ran out of TrueScale McKee bodies, and the older ones on the 1237-1240’s had been banged up during this past year of tuning and testing, so, to keep everything uniform during testing and comparisons, all the chassis/cars, including the 1245’s, are now topped with Parma 1041-B Ti-22’s (and, of course, painted in CMF3 white-color-black tricolor chevron livery, so as not to be confused with every other Ti-22 out there… and so my addled brain can remember which car is mine…).

 

Testing Update:

 

I got over to Fast Eddie’s Raceway last week to re-sort all the CanAm chassis littering this thread since reconfiguring them back into “test mode”; for those who have lost track, to date these seven chassis are:

1237-Cc2

1237-Cc3

1238-Cc3 *

1239-Cc3

1240-Cc3

1245-Cc2

1245-Cc3

Part of this included that all of them have a relatively equal bunch of “reasonably fair-to-middling” test motors pushing them around, and, with the rule change for 2017, are now all R-Hawks.

 

With few other slot car geeks present for Test & Tune last week (and this week), and the Hillclimb at Ed’s in excellent condition, I was able to run all cars on Orange, Black and Red lanes, getting enough testing data to warrant using a spreadsheet to sort it all out. I had noticed trends previously with the 1237 - 1240’s where certain chassis showed preferences for various lanes; adding the 1245’s to this mix only complicated all this further. And people wonder why I write all this down in notebooks…

 

The short version: Typically the 1245’s run best on the middle to lower lanes, while the 1237’s run best middle to upper lanes, while the 1238 runs best in the middle, and the 1239 & 1240 are “gutter” chassis (but the 1239 better on upper, and the 1240 better on lower). Keep in mind, all these chassis are extremely even in overall performance (averaged across all lanes), and I would have a hard time objectively selecting any one as my “go to” race chassis, while at the same time having no problem choosing any one of them.

 

In another WAG tune/test experiment, the 1245-Cc3 had a 0.024” wire “sissy bar” added, running from the rear axle tubes to the top-underside of the Ti-22’s rear spoiler; it appears to have smoothed out the handling for this chassis, and was the main reason for putting a sissy bar on the 1241 at the onset. More testing needs to be done in this regard before putting them on the other 0.032” wire framed chassis.

 

So the idea with building the 1241 was to get even better handling across all lanes.

 

* 1238-Cc3: For those of you keeping track of all this, which I imagine is no one, though I’m not superstitious, knock on wood, over the course of this year I’ve come to consider the 1238 to be a “cursed” car, a phenomenon I’m sure some of you understand. If someone decides to put their hand on the track to pick up their car, if another car you just passed follows you kamikaze-style into the next turn, if there is a car off under the bridge and the driver doesn’t bother to say, “Caution under the bridge”, if another car on the track decides to stop dead in the high bank for some unknown reason, the 1238 will find it unfailingly. If nothing else, the fact the 1238 still runs has at least shown me many of the structural aspects of these chassis under “trauma” conditions… All that said, the ding-dang thing is still as competitive as any of the other chassis, even running the outright fastest lap of the last week’s testing, and second fastest this week… go figure…

 

1241-Cc3 Test Run:

 

Sorry. I realize this post is getting overly long, but sometimes the simplistic approach is insufficient to having a complete understanding. I went back to Fast Ed’s last night, so, here’s the scoop on the new 1241:

 

It worked. The 1241 was outright fastest on Orange (better than the 1238), was right there with the 1240 and 1245’s on Black, and just behind the 1237’s on Red (but the 1239 is a rocket on Red). Overall the 1241 averaged the best performance across all lanes.

 

But… that is just the first time out; it needs to be able to do that consistently with time…

 

Still, this was “out of the box”, so it bodes well; and I didn’t play around with the tuning screws, except to see if there was finer tuning of the 0.024” VSW’s on the 1241 versus the 0.032” VSW’s on the 1239 and 1240; there was. More to be determined on this matter.

 

That’s all folks!

 

Rick / CMF3

[Bryan Warmack]

Rick,

    Absolutely awesome stuff!        Hope all is well and have a great Christmas and New Years!!

                               Bryan

[Rick Moore]

Thank you, Bryan! Me and the pup dog are still hangin’ in there; not sure how, but I figure it’s best not to think about it too much…   

 

My best to you and yours, and to all the other slot car geeks out there, for the holidays, the new year, and all days!

 

Have fun!

[SlotStox#53]

Superb chassis & detailed testing and progression! I'm amazed you keep track of all what you do before you post on here!

[Rick Moore]

1237-Cb3

 

Time to bring things up to date on this thread. Since my last installment there were some weeks getting the fleet ready for the first 2017 GRRR race at Fast Eddie’s back on 1/29, and then some time off to enjoy some of the distractions offered in FL during February. Just prior to the GRRR race, I opted to throw together one more chassis…

 

Some years ago while playing, er, I mean, testing some of my cars, in particular the 1225-Cb, and 1225-Ca2, Marty Stanley remarked I needed to make a 0.039” wire framed chassis (like the 1225-Ca2) with the “short” chassis dimensions (like the 0.047” wire 1225-Cb). That wasn’t possible with the 1225’s, since it would have never been able to make the minimum weight for CanAm class cars…

 

So the 1229’s were designed with 0.039” wire framing in mind, and the possibility of 0.032” wire framing (like the highly educational 1225-Ca3). So, after the “short” 0.039” wire framed 1229-Cb2 and 0.032” wire framed 1229-Cc3, Marty wanted to know when I would build a “short” version using 0.032” wire. Again, though the 1229 design made this a possibility, it would have been pushing it.

 

The “short” version of my chassis, the “b” in the CMF3 chassis designations, have the following dimensions:

 

WB = 3.75”

RAX-GPC = 4.75”

GL = 1.00”

 

What Marty and I both particularly liked about the previous two “b” cars were how they ran both of the gutter lanes. I’d been revisiting the 1229-Cb2, and, even on the Hillclimb at Fast Eddies’s, I still really liked this car, and it still ran the gutters almost as fast as it ran the middle lanes. So…

 

At this point I know quite a lot about the 1237-Cc2 and 1237-Cc3, plus it is the basic design upon which all these others have been adapted, so the 1237 design seemed like the most logical selection for trying a “short” chassis framed in 0.032” wire.

 

And, that gives us the 1237-Cb3:

 

 

 

 

 

 

 

 

 

 

Added a front and rear view with the pics this time, largely out of boredom… I really need to do a full build sequence for the 1237’s one of these days for those few suffering souls who are actually trying to figure these things out…

 

Except for being 1/8” shorter than the 1237-Cc3, having a few extra wires in the framing, and having full-sized dynamic pans (like the 1241-Cc3), the 1237-Cb3 looks pretty much like another 1237. Boring, huh?

 

Mass-wise, the RTR car came out to 95.2 grams, which was more than I thought it would. So the dreaded lead was added to the dynamic pans, making the car 100.1 grams…

 

Initial Test Run:

 

On the Hillclimb at Fast Eddie’s the 1237-Cb3 did what I hoped it might. It was actually better than the 1237-Cc3 on Red, and almost as good as the 1245-Cc3 on Black. Its overall performance across all lanes was statistically slightly better than all others, including the 1241-Cc3. But that’s just one test, and only a week before the races… So…

 

Racing Update:

 

Since the 1237-Cb3 is a new entity, and even the 1241-Cc3 is still relatively new, I chose an “older” chassis I had more experience with, and based on track conditions, opting for the 1245-Cc3 to be my CanAm car (which I had intended to race the last time out, but made the last minute change to the 1237-Cc3).

 

In GT Coupe there was no question, as I’d taken the 1237-Cc2 and dumped enough lead on the dynamic pans to get it to 110 grams… And for Stock Cars I didn’t race the 1237-D2o the first time I ran this class, so it was its turn this time.

 

First race was Stock Cars on the Oval. The goal was to run conservative and keep the average laps equal to or less than 4.0 seconds per lap; I was not the fastest straight line car, and knew it. The 1237-D2o ran flawless, handled predictably, consistently, perfectly. This allowed me to “drive ahead” and avoid any carnage. Averaged 30.25 laps per two minute heats, 242 laps, and was good enough for the win. While I really want to build the asymmetric 1244-D2o stocker chassis, the 1237-D2o ran so good that I can take my time getting around to it.

 

For CanAm the 1245-Cc3 would qualify fourth, and finish fourth in the A Main. I was more than happy with this considering… Third heat on Blue I caught a wreck in the Donut, went rider on Black, and took a full-out wall shot into the Lead-On. The chassis left-front wing was bent back about 1/16^th inch out of square, compromising the left side pan movement, and the left-front buttress rail articulation was damaged. Not good, and not repairable in a race. So I just yanked it as straight and flat as possible, and ran it as a wounded duck... as I said, considering… the 1245-Cc3 was still contending for a podium up to the last heat.

 

(Despite the fact that they don’t appear to be “strong”, or are “wiry” looking, I keep finding the 1237-series chassis will take a serious beating and still run. And the 1245-Cc3 was easily repaired…)

 

In the GRRR “IMSA Class”, where GT Coupe and CanAm Plus run together, the 1237-Cc2, now leaded up as a GT Coupe (I didn’t have any CA+ bodies) and down on speed compared to its CanAm set up, still ran as good as ever, ending up second (I turned one more lap than I did in CanAm). Next time I might opt to lose the lead and set up a chassis for CanAm Plus…

 

Meanwhile, back to testing the 1241-Cc3 and 1237-Cb3… and thinking about the next build…

 

Later gators. Keep having fun.

 

Rick / CMF3

[Rick Moore]

Testing Update:

 

What’d It All:

 

Testing of late has provided some interesting information. The 1237-Cc3 continues to be the “baseline”. The 1245-Cc3 is every bit as good, but inherently different (as noted previously, the 1237-Cc3 runs the “top” lanes better, while the 1245-Cc3 runs the “bottom” lanes better). The 1241-Cc3 and the 1237-Cb3 are both proving to be better “all-around” chassis across all lanes. All four are good enough that any of them would be race worthy…

 

But there were two observations that were becoming apparent, so some changes were made that were worth noting here:

 

1) 4x 0.024” VSW’s:

 

The 4x 0.024” wire variable spring wires (VSW’s) that I had tried on the 1241-Cc3 are apparently more suitable, at least on the Hillclimb at Fast Ed’s, than the 3x 0.032” wire VSW’s on the other chassis with front axle rails. Not exactly sure why; that’s all part of the process. But it was worth trying on the 1239-Cc3 and 1240-Cc3, so they also have 4x 0.024” VSW’s now. If they don’t work, or I need a “stiffer” spring for other tracks, I still have the 3x 0.032” VSW’s, which are easily and quickly interchangeable.

 

2) Sissy Bars:

 

The 0.024” wire “sissy bars” on the 1245-Cc3 and 1241-Cc3 are apparently beneficial. Just as a recap, the sissy bar is a two-bend wire with its ends soldered to the rear axle tube and the cross-wire extending up under and into the rear spoiler of the body being used. Sissy bars are certainly nothing new (we were using them, though with thicker wire, even back in the 60’s), and I’ve always used them a lot on my scratchbuilds. Of late, I always use them on my GT Coupes, F1’s, and Stock Cars. The thing is, if you always use the same body (manufacturer / part no.) for any given chassis / class of car, the sissy bar is no problem; in fact, after the initial set-up it makes mounting subsequent bodies even easier. However, if you’re using different bodies, as I was for a time with my CanAm’s, the sissy bar would typically need to be adjusted or replaced when changing from one body to another. Since all my CanAm’s are now using only the Parma 1041-B Ti-22 body, it was time to add the sissy bars.

 

Here’s a rear pic of the 1239-Cc3 where you can see its new 0.024” sissy bar inside an unpainted body:

 

 

 

The apparent effect of the sissy bar is to apply any downforce on the rear of the body directly to the rear axle and tires (as opposed to being applied to the chassis at the rear body mounts and indirectly to the chassis rear axle), while eliminating any side-wall deformation of the rear of body (forward of the rear wheel cut-outs). On these 0.032” wire framed chassis, which are pretty pliable, especially on the rather scanty side “pans”, this is a distinct benefit; and it certainly doesn’t hurt on the 0.039” wire framed chassis either. So the 1237-Cc3, 1237-Cb3, 1238-Cc3, 1239-Cc3, 1240-Cc3, and 1245-Cc2 all have sissy bars now too. (The 1237-Cc2 already had a sissy bar added for the Parma Lola T-70 Coupe body when it became a GT Coupe.)

 

How’d It All:

 

Last two test/tune Wednesdays at Fast Eddie’s the Hillclimb was in excellent conditions across all lanes; the first time the track was rubbered-in just right, and the second time the track was cleaned and spray-glued to perfection. Makes for great testing, and lots of data.

 

The 0.024” VSW’s were major improvements on the 1239-Cc3 and 1240-Cc3, both cars running their best laps on any lane, and that was with “test” motors, not “race” motors. (This also helps to explain why the 1241-Cc3 was so much better from the git-go…). That, and…

 

The sissy bars improved every car’s handling and lap times; again, we’re talking “test” motors. It was most noticeable on the gutters, Red and Black.

 

In the short term, my “old” Go-To chassis, the 1237-Cc3 and 1245-Cc3, along with the better-than-ever 1239-Cc3, have fallen to stand-by status as the 1237-Cb3 and 1241-Cc3 continue to get better every time out. To put it in perspective, over those last two test-and-tunes, and keeping in mind the ideal but very different track conditions, all five of those noted chassis ran Black and Red significantly faster than previous best lap times for those lanes, and all five ran Orange faster than my last qualifying run and four ran better than my best qualifying run… with “test” motors…

 

(Admittedly, one of those “test” motors is definitely coming out of the car before the next test runs… you know, for future use…)

 

Not bad. Now I have to figure out what each one is doing right, and go from there...

 

…and think about that next build…

 

Oh boy, more slot cars!!!

 

Rick / CMF3

[Rick Moore]

1237 Chassis Build Sequence

 

A few people, very few, were wondering if I’d ever get around to posting a build sequence for one of these chassis. For them, as well as the perversely curious or bored, I am pleased to announce the following thread can be found in the “Tech How-To’s & Tutorials” subforum:

 

CMF3 1237-Cb3 Build Sequence

 

http://slotblog.net/...build-sequence/

 

It should go a long way to answering the what-wire-goes-where headaches these chassis can produce.

 

As for the chassis pictured in the build sequence, the 1237-Cb3+, a CanAm Plus class chassis, more specific info as it relates to the design progression here will be posted after it gets some test runs. Thank you for your patience, as well as all degrees of tolerance, stressed as it may be...

 

Rick / CMF3

[JHMerriman]

Thanks Rick, I've always been curious how you managed to put these cars together! Might have to try my hand at building one or two.

[Rick Moore]

Hey, James! How’s life and all that?

 

There are probably a million variations on this basic all-wire framing construction… I’m only working from my own experience… I always wondered who would be so crazy… er… I mean… inspired (yeah, right) to try building like this…

 

Funny how many people have told me, “I can’t build like that”, or “I haven’t got the patience for that”, or “I’d quit if I had to build like that”, or…

 

Odd thing is I sort of get this zen-thing as I bend the wires and they fall into place… that, and 0.032” wire is soooooooooo much easier to work with…

 

Good luck. Make sure you have fun. Chanting mantras optional, and probably pretty silly… I recommend loud music…

 

Rick

[Rick Moore]

1237-Cb3+

 

I finally decided to build a CanAm Plus class version of the 1237. Two reasons prompted this decision:

 

First, in the GRRR retro racing series they run races called the “IMSA” class, which is a combo of GT Coupe class and CanAm Plus class cars running in the same race, where you race for overall and class win. Cool idea. I had already turned the 1237-Cc2 into a GT Coupe, leading it up to get to the 110-g minimum. But I also thought it would be nice to have at least one CanAm Plus car in the stable to have as another option.

 

Second, since the CanAm Plus class does not have a minimum weight regulation, this would provide me the opportunity to explore some of the anecdotal wisdom that the minimum weights for these in-line classes make the cars “easier” to drive.

 

To this end, I built another 0.032” wire framed 1237 using the short “b” dimensions (3.75” / 4.75” / 1.00”). Since I already had the CanAm class 1237-Cb3 and the 1237-Cc3 (3.875” / 4.875” / 1.00”), where I was also able to compare the common wisdom regarding shorter wheelbase cars (contrary to popular belief, the shorter “b” car is actually faster, especially in the gutter lanes, and just as easy to drive, at least on Ed’s Hillclimb…), I’d be able to see one-on-one how the “unleaded” CA+ 1237 car compared to the heavier CA 1237 versions.

 

It also, as many of you might be aware already, gave me the opportunity to post that build sequence for the 1237 that has been on my O2It list. All in all, a good opportunity… and fun too…

 

So, the 1237-Cb3+ came out like this:

 

 

 

 

 

 

 

 

All things being equal, they aren’t, of course. The 1237-Cb3+, besides having the smaller front wheels with lower front axle set, does not have the dynamic pans used on the 1237-Cb3 (used to get the mass up and offer a place to tack on the dreaded lead). And of course, there’s the body, for which I went with the Parma #1057-B Gulf Mirage. Other than that, it’s the "same" chassis and car… even both have sissy bars…

 

All told this put the RTR weight for the 1237-Cb3+ at 90.2 grams. That’s 10 grams lighter than the RTR 1237-Cb3.

 

First test at Fast Eddie’s on the Hillclimb, the track was “looser” than the previous two outings, but still in very good condition. Any time the track starts to loosen the 1237’s lose a little, while the 1239 runs as fast as ever, if not slightly quicker. I also found out the 1241 holds its own even as the track gets slicker, losing little, if any, speed and handling at all (with different “test” motor in it, since the last one got “put away”…), so the 1241 continues to test nicely.

 

As for the 1237-Cb3+, the thing is a rocket. Not pushing around that extra 10 grams is immediately noticeable. Not surprisingly, the braking improved also, which was very apparent and welcomed on Black coming into the Deadman.

 

As for the handling, it is every bit as easy to drive as any of the 1237’s, and after a couple rounds of laps it was easier. Even easier than the 1241.

 

Out of curiosity I added about 2 grams of lead to the car, to see if the handling would be the same, improve, or worsen. With the lead the car tended to “push” more entering the turns, most noticeable entering the Donut, and was more prone to deslotting when it had just previously run with no problem; so it made it harder to drive. I took the (expletive omitted) lead off, and ran again just as fast and easy as before. So much for lead…

 

When all was said and done, the 90-gram 1237-Cb3+ CanAm Plus ran Red, Orange, and Black a full tenth-or-more faster than the 100-gram 1237-Cb3 CanAm, as it should have, and was easier to drive faster, which was a pleasant surprise... (In fact, even compared to the 1241-Cc3, the 1237-Cb3+ was lights out faster and easier to drive.) Granted, that is only one set of test runs on one evening on one track in those singular conditions…

 

…but I can’t say the results are giving much concern on my part…

 

Disclaimer: Your results may vary…

 

This is fun. More cars to come. Consider yourselves warned.

 

All you other big kids go have some fun too.

 

Rick / CMF3

[Rick Moore]

1241-D3o
 
It was time for another stock car. The 1237-D2o was built about ten months ago, and has done pretty well testing, and won its first race back in January. The asymmetric stock car 1244 design is still nothing more than a bunch of drawings and notes, but has contributed to the 1245’s, the 1241, and even the as yet unseen 1250; whether the 1244 ever gets built is becoming less and less likely, but who knows…
 
In any case, I opted for a stock car version of the 1241. However, unlike the 0.039” wire framed 1237-D2o, I decided to throw caution, and generally accepted anecdotal wisdom, to the wind, and frame this chassis in 0.032” wire. So this one is the 1241-D3o:
 

 

 

 

 

 

 

 
 
As before, since this is a left-turn-only car, pans fill the left side of the frame. Since the 1241 incorporates variable spring wires (VSW), and based on what I’d learned with the 1239, 1240, and 1241, the LTO stocker 1241-D3o has a 3x 0.039” wire VSW on the right, and a 4x 0.024” VSW on the left. Other than that, just another one of these chassis… y’all getting bored yet…
 
The RTR 1241-D3o car came out to 118.1 grams, more than I thought it would, less than the 120-gram class minimum, but only about 1 gram less than the original RTR weight on the 1237-D2o; not bad. And just as I did on the 1237-D2o (which currently runs about 132 grams), I already had precut lead to sit on the left side pans of the 1241-D3o ready for when it gets on the track for its first test run…
 
Which was this evening…
 
A picture of the oval track at Fast Eddie’s can be found under the raceways listing on Slotblog for those unfamiliar with it. Suffice it to say that the “killer” is the pretty-near flat sharp turn before coming into the drivers’ stand short straight… and the fact this turn sits at the end of the longer straight after the bank turn at the opposite end of the track… meaning you’re carrying a lot of speed into this turn… Therein lies the conundrum for car set-up on this oval track, to gear for speed on the long straight and the banked curve and the longer straight, or to gear for that flat dang-near hairpin and the short drivers’ stand straight and the kink… Kind of fun, really.
 
First laps of the “unleaded” 1241-D3o were, not surprisingly, quicker than the 1237-D2o, what with a relative deficit of 14 grams; speed out of the hairpin and the kink was better and smoother, and the braking into the hairpin was very much better. This was despite my being off on the guide depth set-up for this car, and having to remove a 0.010” spacer. After playing around with different added mass combinations and totals, to accommodate the 120-gram minimum class weight and to explore the left-turn-only unbalanced advantages, the best test set-up for the 1241-D3o wound up at only 124.1 grams, which is still about 8 grams less than the 1237-D2o, and quicker still. The lighter 1241-D3o car also allowed me to investigate lower gear ratios that are largely not possible on the 1237-D2o, with the counterproductive loss of braking more apparent on a heavier car. Matter of fact, I was tending to brake too soon on the 1241-D3o initially, and had to remember to correct for this operator error as the testing progressed. When it was all done, or at least when I ran out of ideas for the night, the 1241-D3o was easily running around a half-tenth to full-tenth faster on red, orange, and black (the short distance lane, but that hairpin is crazy-tight), and with the same consistency as the 1237-D3o. Not bad for a first run.
 
It has occurred to me I’m probably having way too much fun with this...
 
Have fun!
 
Rick / CMF3

[Rick Moore]

1121-Cc4

 

If there was ever a post to affirm that this thread is not where you look to see beautifully crafted chassis construction, with precision cut pieces held together with perfect solder joints and tumbled to an immaculate shiny presentation, this one should do it.

 

And, no, that is not a typographical error. This is actually an 1100-type chassis. Long-suffering followers of my builds may recall from some years back the 11XX chassis as 0.010” brass sheet backed with steel wire framing. The 1100’s predate the 1200’s largely due to the fact that I was unsure back then as to my abilities to construct all-wire 1200’s with the required wire-bending and fitment accuracy, so the 1100’s allowed for a greater degree of tolerance (error) in that regard, as well as practice.

 

CMF3’s Improbable History: The idea of building wire framing atop "thin" brass sheet was actually something I thought of back in the late 60’s, but never got ‘round-to-it, as I was busy trying to build like everyone else back then… well, mostly… So, having restarted slot cars and picking right up again scratchbuilding chassis, it wasn’t until the latter 90’s I finally got-to-it. There were three attempts, largely trying to copy other chassis designs into this different construction technique, which met with varying degrees of failure, as well as offering varying degrees of insight. Then I decided to just come up with something simpler and of my own design… The 1104 worked. No one was class racing scratchbuilds back then, so the 1104, an anglewinder using 0.047” wire on 0.010” brass sheet, was relegated to racing flexi chassis in the Wednesday night run-what-ya-brung races on Phil Neatherly’s (“the Godfather of Team CMF”) much-dreaded six-lane shoe-horned-into-a-one-car-garage club track at Dealer’s Choice Raceway in Tampa. The 1104 could beat flexis, and did so on a regular basis…

 

Back to the present: The legality of these 1100-chassis under the auspices of organized retro slot car racing regulations has been an On-again/Off-again sort of thing. It would appear they’re still Off, but with a minor adaptation should be On… I think… maybe… In any case, I had to plow back through my notebooks to see where I’d left off with the designs of these things…

 

But another reason why I really wanted to resurrect the 1100’s is the “4” at the end of this chassis’ nomenclature… The 1121 (and similar 1120, it morphed out of) would be 0.024” wire framing on 0.010” brass sheet... which sounds real flimsy, even to me, but, considering I’m building all-wire framed 1200’s out of 0.032” wire, the cumulative 0.034” thickness of the 1121 didn’t sound utterly unreasonable… weird, but not unreasonable…

 

On all prior 1100’s I would cut the brass sheet and build the framing atop. This time I’m building the framing first, then attaching the brass sheet and trimming. This would also allow me to examine the 0.024” framing by itself before attaching the brass sheet. Sounded interesting, but, as previously noted, I’m easily amused and don’t have a life…

 

So, basically the 1121-Cc4 is a 0.024” wire 1237 frame on 0.010” brass sheet. I kept the “c” dimensions on this build for comparison with the rather well-known 1237-Cc3.

 

And it looks like this:

 

 

 

 

 

 

 

 

 

 

 

Kind of cool looking, in a weird kind of way. The only significant change to the basic 1237 framing was the addition of “knee braces” to the buttress rails and the side pans. However, there are some matters that need to be addressed at this point.

 

First, there is the matter that brass and steel have different heating/cooling properties and rates, and as such will cause warpage when soldered together. This is much less noticeable with thicker pieces of brass and steel, but as that thickness (and, hence, the rigidity) decreases the degree of warpage of the component parts becomes greater. So the process of soldering small diameter wire to thin brass sheet requires a fair amount of effort to minimize this effect, as well as a lot of correction. This is one reason the steel wire framing is not attached to the brass sheet along lengths of the entire framing, but instead is “spot soldered” at critical junctures. I’ve built a fair number of these, so I have a pretty good idea what needs what, and what to expect to some degree. But, for this reason I no longer recommend others to even attempt this type of construction method, except for the most experienced of builders. However, if you’re a glutton for punishment…

 

And then there is that whole “legality” thing I mentioned before. Under the relevant rule set of discussion, brass plate or sheet cannot be used as a “main rail” material (oddly, this contemporary regulation would have made some of my ’68 and ’69 chassis illegal had it applied back then… I’ll spare you the details…), but may be used to form the rear (motor bracket) of the chassis and the front (guide tongue mount) of the chassis, which the “main rails” are defined to connect. Previous 1100 chassis were all one solid sheet of 0.010” brass, which means there was no demarcation between the “front” and the “back” of the chassis, and as such do not meet the regulations in this case. To accommodate this, the 1121 has a narrow split between the brass sheet on the front of the chassis and the brass sheet on the rear of the chassis. See the pic:

 

 

 

While this minimal separation is probably questionable under the rule set, it was solely incorporated to meet the letter of the rule for this particular (and peculiar, some might add) type of chassis construction, and was in no way intended as some attempt to “bend” or “push” the rules.

 

So why bother with all that? The thing is, this type of chassis construction tended to work rather well in the past. It eliminates the lateral loading “spring” effect of small and/or minimal steel wire framed chassis, as well as dampening the harmonic/vibrational effects of all-wire frames. Granted, the 1237-series have gone a long way to negate these inherent tendencies of all-wire framing, but the 1121 was still worth investigating (even if at some future time it should be deemed to not be within the regulations) as a platform to offer some relative comparison in the 1237-series. And, as mentioned, it also presented a good opportunity to explore building a 0.024” wire frame. A “win-win” really, even if not a “”win-win-win”.

 

Yadda yadda yadda…

 

The RTR weight came out to 105.0 grams. Oops… Went back and looked at my math guesstimation and realized I was off by “ten”… You’d think I could at least do simple addition by this age… In any case, it is what it is (the chassis and my mental capacities).

 

Test run: Pretty good. Doing the typical Orange, Black, and Red runs, the 1121-Cc4 ran laps as well or better than the 1237-Cc3 and 1237-Cb3 (the two chassis that are most structurally similar); it demonstrated no deficiency on any of these lanes. It also exhibited all the previous positive characteristics of the 1100-series, and has already set a new standard for this type of chassis; it is a very stable and predictable platform. (A rotten head cold abbreviated this session, but enough laps were completed this first time out for a valid first assessment… stupid cold…)

 

All said and done, for the time being, this little experiment has already offered a wealth of understanding about 1100-type chassis design and construction, 0.024” wire framing, the progress of current all-wire chassis in general, and even a few “Ah-Ha’s” just scratchbuilding this thing. Nice to know even an ol’ dog can learn new tricks… even if he can’t do basic math…

 

Nap time. More fun later.

 

Rick / CMF3

[Rick Moore]

1241-Cb3

 

Coming:

 

This one had to be done to help clear up any pesky remaining doubts before moving on to the next set of designs. At this point the “short” 1237-Cb3 and the “long” 1241-Cc3 are typically among the best of the bunch on any given day. The nagging question was would the advantages of the “shorter” 1237-Cb3 versus the “longer” 1237-Cc3 transfer similarly to the 1241. A second “test” in this design series would not only give a confirmation or negation, but allows additional observation “data” in any case… So, whether it does or not was worth investigating.

 

For those not self-loathing enough to plow through the previous posts, here’s a quick refresher reference of the chassis dimension designations:

 

“c” :  WB = 3.875”; RAX-GPC = 4.875”; GL = 1.00”

“b” :  WB = 3.75”  ; RAX-GPC = 4.75”  ; GL = 1.00”

 

And, other than the dimensional aspect, the 1241-Cb3 looks just like the 1241-Cc3:

 

 

 

 

 

 

 

And a side-by-side pic, for visual reference; the 1241-Cc3 left, and 1241-Cb3 right:

 

 

 

After getting all the runny bits and the body on, and the sissy bar added, the 1241-Cb3 RTR weight came out to 99.3 grams (versus the 101.0 grams of the 1241-Cc3), so two small pieces of the dreaded lead were added to the dynamic pans between the center main rail and buttress rails to make it 100.2 grams.

 

Going:

 

Ed’s was closed last week, so I had to wait until tonight to get to the raceway. Of course, the 1241-Cb3 would be compared versus 1241-Cc3 as well as the 1237-Cb3 and the 1237-Cc3 (I run the 1237-Cc3 every test session, being the second oldest chassis in this progression, and the chassis I am the most familiar with, and it just being one dang-good car, to gauge track condition and to set some baseline lap times).

 

The best-laid plans of mice and men…

 

I had switched some motors around in a bunch of cars, and let’s just say the one I put in the 1241-Cc3 was rather pedestrian, and the one in the 1237-Cc3 would be a run-over pedestrian…

 

Still, even without the usual “side-by-side” comparison this time out, the 1241-Cb3 ran some empirically real good laps, was every bit as easy to drive as the 1241-Cc3, and was quicker than the 1237-Cb3. (And, FYI, the 1121 may be one of the easiest to drive cars I’ve ever built…)

 

(I was also able to get in some testing of a new ProModel controller I just received today versus the S&K controller I got last year… part of the ongoing saga of “Disposable Income and The Single Guy”… but that’s a story for some other time in a sub-forum far, far away…)

 

At this point I’m ready to say any preconceptions some out there might still harbor regarding shorter wheelbase cars may be worth some reconsideration; as for me, I can definitely see the value in testing these things first-hand…

 

But more testing, especially after tonight’s circumstances, is definitely in order. Dang, guess I’ll have to go to Fast Eddie’s Raceway more…

 

What a shame, huh?

 

Gone:

 

Rick / CMF3

[Rick Moore]

Sidebar: Red Fox guides

 

There’s been some blog-buzz about the new Red Fox guides. Let’s see…

 

I’ve been using the old Red Fox guides, the molybdenum-graphite ones, since they came out. Then and over time I’ve compared them with other available guides, and at no point saw any reason to stop using the RF’s. I always got best lap times and overall handling with the m-g RF guides. Other people have had varying results…

 

First, I heard many of the reports by other slot car geeks running the old Red Fox guides and having them break, but never once experienced this myself in all that time, even with the most horrendous of wall shots. Maybe I was just lucky all those times, or maybe the front wings on my chassis designs help to mollify this result, I can’t really say. I can say I have had no failures to report for a large number of RF guides in an equally large number of slot car chassis (all scratchbuilds) in various classes.

 

Second, there is the matter of having the guide post snap off during threading, which is something else altogether, as I have experienced this numerous times. Digging that post out of your threader is a royal pain in the nether-parts, and is one of the reasons I own two threaders... But experience on my part finally eliminated this problem.

 

So, while I hear others reporting improved lap times of 0.1 s or more in various slot car classes with these new Red Fox guides, it is rarely mentioned versus what previous guide. In any case, being an innately skeptical person who rarely if ever believes anything others tell him, and having that whole annoying science background that demands peer review and duplication of test results, here is a comparison of the old RF guide versus this new RF guide on one of my retro CanAm cars.

 

For my first test platform I decided to use the 1241-Cb3. I already had a fair amount of test runs and data on this chassis/car, and also knew very well its handling characteristics, especially relative to its sister chassis/car the 1241-Cc3.

 

These new RF guides are nylon. I wonder if they’ll become available in the black molybdenum-graphite…

 

Physical observations:

 

I have some of the old that were supposed to be the molybdenum-graphite guides, but when I shortened the guide post they were white on the inside, so they are nylon dyed black (anyone else find some like this?); I used these to compare to the new guides. The molding quality of the new guide is far superior to the old guide which always required some “clean-up” before threading and mounting. The new guides appear larger, and weigh on average about 0.1 gram more. The blade depth is pretty much the same. The blade thickness is changed, the old RF’s tapering (thinner at the top, thicker at the bottom) and the new RF’s having straight sides; comparing the bottom of the old with the new, they are about the same (the new around 0.002” thicker). The distance from the guide post pivot to the front of the blade, as best as I can measure it, is also the same. The blade length, again comparing the bottom of the old RF (the length also tapers) with the new RF is pretty much the same (the new at most 0.002” shorter). The guide platform is noticeably larger. The biggest difference I could find was the thickness of the guide platform under the guide post (old and new being “cut-down” guides), with the new RF’s being about 0.009” thinner, so to keep the same guide depth set-up adding another 0.010” spacer would be in order when switching from the old RF guides to the new RF guides. The front of the braid housing atop the guide platform is about 0.1” farther forward of the guide post on the new guides, so the braid (along with guide clips and lead wire) will correspondingly be farther forward also (you may need to check for body clearance as well). And, the diameter of the guide post on the new RF’s is about 0.003” less than the guide post on the old nylon RF’s (the old moly-graphites were slightly larger still), which brings us to…

 

Threading:

 

As an FYI, I found the straight-sided blade on the new RF guide would not fit the slot (too snug) in my old red plastic Cahoza threader, but was okay in the slot of my metal Kolhoza threader. Honestly, I never had much problem threading the old nylon RF guides; it was those dang moly-graphite ones that could be problematic. Once I learned my lesson (lessons), I would cut most of the unnecessary length off the top of the guide post on all the old RF guides before threading (to cut down on the amount of friction while threading), and never snapped another post since. But for the new one, I decided to thread the first one with the full length of the guide post just to see how it was. For all intents and purposes it seemed to be about exactly the same as the old ones, the slight difference in diameter being negligible during manual threading. Same goes for driving on the guide nut, no difference that I could tell. (And, yes, it did need another 0.010” bronze guide spacer.)

 

Now, where it counts, in the slot:

 

Testing is, of course, on the fast 153’ Hillclimb at Fast Eddie’s Raceway in Pinellas Park FL across the T-Bay from my domicile in Tampatown.

 

A tenth? Really?

 

On the 1241-Cb3 I just wasn’t seeing it. Nor was I seeing any general improvement with regards to previous testing for general handling or consistency. Not sure of my results, I played around with the guide ride height some, confirmed I had it right, so then I switched back and forth between the new Red Fox guide and the old Red Fox guide. The only measurable differences for lap times between the two guides was in the thousandths… less than one-half of one one-hundredth, or < 0.005 s… For all intents and purposes the same… Nada… Zip…

 

More questions than answers:

 

Okay, this was one car on one track on one night. Further testing is in order, certainly, and will continue for my part…

 

So why is there none of the hyperbolic improvement indicated by others? Good question. One possibility is that the 1241’s are probably my best handling fastest chassis to begin with. Maybe on a chassis with other or lesser characteristics the improvement would possibly be greater.

 

Maybe it is that the new RF guide is that much better than other available guides other than the old RF guides.

 

I don’t know.

 

Don’t get me wrong, I am not disparaging the new Red Fox guide in the least. It is an excellent guide. That, in and of itself, is more than enough reason to buy and use them.

 

But a “tenth”? At this point I’m just not ready to confirm such results.

 

Of course, your results may vary…

 

Rick / CMF 3

[Rick Moore]

Racing Update:

 

I was able to schedule this weekend off from work so I could attend the combined FSCS/GRRR races at Fast Eddie’s Raceway on Saturday, 6/10. The only GRRR retro class scheduled for the event was CanAm, the second class run that day and on the Hillclimb, so that was the only race in which I would participate. For you competition types out there who want to know how these designs and constructions are doing, here’s your latest fix.

 

I pretty much knew weeks, months, before that this would be the race for the 1241-Cc3. While the 1241’s, by having been the last “chronologically” (not “numerically”) in the 1237-series, benefit from the lessons I learned in the design and construction of the 1237’s, 1238, 1239, 1240, and 1245’s, it was that one test session where by complete accident and/or luck I’d hit upon a very good set-up for the 1241-Cc3; I made my notes, pulled the motor, and that was that, at least until something else proved better. (And for those still wondering and pondering, this set-up was with the old Red Fox moly-graphite guide, not the new one…)

 

The 1237-Cc3 and 1237-Cb3 are still fast by any comparison, but could not quite match that 1241-Cc3 set-up. The 1241-Cb3 could run as fast, and though very good (it was my back-up car for this race) I just couldn’t find that “perfect” set-up that was as consistent across multiple lanes as that set-up on the 1241-Cc3. So, ten days before the race I re-set the 1241-Cc3, ran a few laps to confirm, and stuck it back in the box.

 

For the CanAm race there were 21 entries. Since I didn’t have to do any pre-race thrashing on the car, I just put on new braids, oiled it, put on new tires, and did about 5 laps to scuff them. I ran practice laps with the 1237-Cc3 and 1241-Cb3 to monitor track condition, which was showing improvement as the day progressed. So when tech opened, I was the first car in, and would be the last to qualify.

 

The track condition was “fast”. Jeff Bonanno, Dennis Demole, and Jay Guard had all qualified faster than the previous track qualifying record for CanAm class, 4.638 s, with Jay laying down a killer 4.608 lap. The best I’d ever had the 1241-Cc3 previously was 4.628 and 4.622, but not in race trim. Normally, being kind of lazy, I’d just run enough qualifying laps to get a time to put me in the A-Main (needing a sub-4.70), but that time Jay had run was so close to getting a “4.5-something” it kind of motivated me to go for it. So after running a 4.674 on my fourth lap, I kept going… and ran a 4.538 on the next lap… then I stopped.

 

After picking up my lower jaw…

 

The CanAm A-Main was crazy fast, and the first half of the race was close. By the last heat Brian Ambrose and I were tied for first, with Terry Tawney (who’d qualified 7^th, and won the B-Main to move up to the A) lurking right behind if we screwed up. Brian finished on Black (which you might think was detrimental, but I knew I had turned 37 laps on Black…), but I was on Orange.

 

When it was done, all three podium positions had run better than the previous CanAm class race lap record for the track, 288. Terry was third with 289, Brian was second with 290, and I won with 291.

 

So, yes, these chassis can be competitive…

 

But in all honesty, and in all proper perspective, in addition to spending a disproportionate number of hours happily designing and building these things, it’s just a great day any time I get to race with a great bunch of people at a great raceway, and simply a ton of fun. The TQ and win were just the proverbial icing on the cake (which, along with other celebratory snacks, I literally bought on the way home…).

 

And I wasn’t at work. Cool.

 

Have fun.

 

Rick / CMF3

 

[Rick Moore]

Just for fun…
 
Be sure to check out the UMDF Fundraiser I’m having!
 
Your donations get you entries to win a brand new ready-to-run CMF3 1237-Cc3 Can-Am class slot car!
 
CMF Slot Car UMDF Charity Fundraiser
 
Make a donation and join the fun!
 
Rick / CMF3
 

[Rick Moore]

So far…

 

Time for a recap. It’s easy to lose track of all this, to say the least…

 

Thus far there have been 18 chassis designs that have been constructed in the 1237-series progression. For a quick chronological-by-class review:

 

CanAm class (11)

1237-Cc2

1237-Cc3

1238-Cc3

1239-Cc3

1240-Cc3

1245-Cc2

1245-Cc3

1241-Cc3

1237-Cb3

1121-Cc4

1241-Cb3

 

F1 class (4)

A214-c2

A215-c2

A216-e2

A216-e3

 

Stock Car class (2)

1237-D2o

1241-D3o

 

CanAm Plus class (1)

1237-Cb3+

 

Time for the next chassis…