3573 replies to this topic

[havlicek]

I added can and endbell bearings to this old Mura as the existing bushings were a little sloppy...not good. The difference is LARGE and this motor screams now.



-john

PS...your arm is on the way Bill and I found a #24 awg with pretty high timing that should satisfy your Grp 7 jones

[wilbor56]

TKS John i have stoped shaking already.

[havlicek]

Getting ready for the next motor, a nice Champion, there was some things to take care of before winding. One of the (many) weak spots for these motors is the endbell bushings, and often the fit to the arm shaft is sloppy even on a NOS endbell. The Tradeship endbell is really nice, but the bushing hole is so small that fitting something in there seems impossible. You could cut a piece of flat brass or steel and screw it onto the outside but I think that would look sloppy and make endbell drive a pain in the neck. The Champion endbell, at least the one I got, has more possibilities in this area and also more room inside for a larger com should I decide to go with something wider than the Tradeship.

Problem with the Champion endbell is that the bearing/bushing hole is somewhere just under 6.5mm...a weird size, but it turns out that K&B 1/4" tubing's OD (I think that's the size) is a pretty good fit for the endbell, but too small ID for the bearing. So I reamed out the end of the tubing carefully until I could tap in a bearing and then soldered it to the tubing. I then cut off the extra tubing and reduced the OD until the bearing and sleeve "snapped" into the bearing pocket of the endbell. Drilling-out and reaming the can was realtively easy, so I also did that and soldered in a bearing on that end (and also soldered the brass to the can while I was at it. Now an arm fits snug in the Champion and spins the way it should. The 26D shim will be cut down to use here to tighten the airgap. After all that, there was some rust oin the can so I stripped it and gave it a coat of black textured finish Rustoleum.



-john

[dc-65x]

Nice setup John. That textured finish Rustoleum paint is really cool. I've used the dark green good stuff. I haven't put ball bearings in a Champion setup......yet. Now I know how. Thanks!

Rick

[Horsepower]

Man, that is some nice, precision work, John. I don't know how you can solder the bearing to that small ring of brass, though. Id have a nice blob of round silver solder when I was done. The paint came out nice also!

[havlicek]

Nice setup John. That textured finish Rustoleum paint is really cool. I've used the dark green good stuff.

Hi Rick,

I've only found the Rustoleum Textured Finish paint in black...dark green sounds like it would be really nice. For this old Champion, the black seems cool since the can was that matte black originally. The "Hammered Finish" Rustoleum is also great stuff...very hard/shiny/durable and available in several nice colors.

I haven't put ball bearings in a Champion setup......yet. Now I know how. Thanks!

Rick

oh...I don't know...I think you'd manage just fine The can end is pretty easy, but the endbell was a bit more of a problem...but still plenty doable. Sleeving the bearing and then cutting the assembly off the larger brass tube you sleeved it with always presents the potential of getting brass powder and flux residue inside even a shielded bearing and sure enough the bearing felt a little rough when I cut it and the sleeve away from the tube. Also, washing it in baking soda and water with a small brush afterwards to be sure to get any flux residue neutralized and out of there probably doesn't help. I spent a while with some Slick 7 bushing/bearing lube spinning the bearing by hand with an old arm shaft, cleaning & re-soaking with more lube until it felt smoooooooth. Then I mounted the sleeved bearing on an arm shaft chucked in the Dremel and soaked it some more in Slick 7 and spun it while holding the sleeved bearing in my fingers...clean/re-soak just to be sure it was golden.

I was able to get a really nice "snap-fit" of the bearing into the bearing pocket of the Champion endbell by just taking down the OD a teensy weensy bit at a time, so that wasn't a major deal. However, because I like to live dangerously ...I also roughed-up the inside of the bearing pocket and applied a few molecules of hi-temp epoxy with the end of a round toothpick before popping the sleeved bearing in for good. I then baked the endbell at a very low temp in my easy-bake oven for 15 minutes to help force-cure the epoxy and that bearing isn't going anywhere soon! This was the most worrisome part of the whole deal because the epoxy I use is very low-vis and gets even more so with a little heat. The slightest amount running into the bearing would have ruined the bearing I just worked so hard on , but I got lucky

I don't know how applicable any of this is to what you do anyway Rick because even though there were bearings in use back then, the ones I've seen have been larger and even less "precision" than the bushings. So to be true to the period, there'd have to be some good quality bearings that would fit from back then??? If there are, I'm SURE you'd find them!

Man, that is some nice, precision work, John. I don't know how you can solder the bearing to that small ring of brass, though. Id have a nice blob of round silver solder when I was done. The paint came out nice also!

Hi Gary and thanks! Really, it's not all that hard, more tedious than anything, and I did a little figuring beforehand of how I could attack the problem with the tools I have. First off, the small ring of brass wasn't a small ring when I did it. I first reamed out the end pf a full 12" piece of brass tubing until the bearing could be tapped-in flush with the square end of the tubing. Because the tubing was pretty thin-walled at that point from the reaming, the previous "slide-fit" to the endbell now was a very tight fit as it expanded a bit tapping in the bearing...too tight to not worry about splitting the endbell around the bearing pocket which is/was a common problem even with the factory setups. I also used just a tiny amount of acid flux on a very small artist brush before heating the assembly to solder it and then tinned the whole outside . I used a flanged bearing to be double sure that when the bearing seated to the square end of the brass tubing it would have a positive stop, even though the bearing flange OD was too large for the bearing pocket of the endbell. I figured I would be taking down the OD of the whole mess afterwards to get the right fit anyway and grinding off the bearing flange until it was flush with the bearing sleeve was just part of getting the whole OD right for the endbell. Anyway, I cut off the bearing and sleeve from the big piece of tubing only when it had to be done and then carefully ground the overcut flush with the end of the bearing that had been inside the tube. The result was that the bearing and sleeve all ground down looked like an unflanged bearing with an OD of a little under 6.5mm. Like I said, it was tedious...especially just to get a bearing to fit, but not that difficult.

Why go through all this? Well I've done a bunch of these lately and even when I'm sure the arm is balanced and the shaft is true, they never seem to run super smooth like the later Muras for example, and even a little "buzz" from an arm spinning in a sloppy bushing is a motor-killer. The com will wear faster and arc more (drawing a bit more current) and the relatively soft bushings will wear making the problem get worse over time. Under a bright light, I have been able to hold the shaft and even see a tiny bit of side play when I try and wiggle it. I guess racers from the period may have just dealt with it, but it seems more likely they had access to better bushings and bearings (???). Of course, if I had better tools a simpler thing to do would have been to use an oversize but tight-fitting bushing and turn it down to fit. That would even be a simple way to get a slick bushing to fit even the tiny pocket of say a Tradeship endbell! It would be a snap (with the right tools) to get a few current, and inexpensive, bushings and turn them down to whatever OD you need. Anyway, thanks for looking Gary.

-john

[dc-65x]

Thanks for the ball bearing how to. I really like to use them too. There were good and bad ball bearings back in the day so I say ONWARD!

Have you notice that Mura A-cans (16D) and B-cans have 1/4" bearings? Todays slot car ball bearings are 5mm or 6mm. I've got a pretty easy method to get these cans "bearing'd up".

Oh, here's what the green textured paint looks like:



Thanks again John.

[havlicek]

Hi Rick,

I've not noticed that...I just tend to use whatever fits...or try and figure a way to make stuff fit. It usually involves ball-peen hammers, explosives, crow bars and the like I LOVE the way that green looks! It seems a lot like a slightly lighter shade of racing green from the picture if the color representation is good. Now I'm going to get me some!

-john

[havlicek]

I got the setup for the Champion complete. I soldered the brush holders, drilled and tapped the endbell for larger/longer screws to hold the brush hoods, drilled the endbell for the button head retainer screws, added post protectors, shimmed and installed the magnets with a new pair of spring clips I bent from some .049" piano wire and shined-up everything. Putting an arm in there to see again if it spins the way I want it confirms that all is good!

Now I just have to wind an arm for the thing and that will most probably be a #28awg (single of course) as I've worked up a ouple of winds for this kind of setup that seem really strong, but not crazy. I really like this Champion, even though the chrome cans are prettier I think. The endbell material seems way better and tougher than the white Mabuchi stuff.



-john

[havlicek]

For a blogger...or rather his customers. A "hat-trick" of modern 16Ds done as #28 singles. Polished/balanced/coms recut blah blah blah. It's a wind I've done for him before and seems to work well on his track.



-john

[Horsepower]

That work on the ball bearing simply amazes me. No one takes the time to do that kind of precision work any more. Ah, maybe a couple of master craftsmen here on SLOTBLOG! but that's it. You always seem to come up with ingenious ideas for motor problems. I have some great ideas too! As soon as I can get one to work I'll clue you in.

[havlicek]

Hi Gary and thanks for looking All this is just a more "grownup version" of the kinds of tinkering I'm sure many of us did as kids. About any car in the 60's, and many car parts, were lacking in some pretty obvious ways so we all did what we could to "improve" things. Of course as a kid, the "workmanship" was pretty horrid but the sometimes successes kept us all motivated and pointed us in the right direction even if our skills weren't up to our wishes. I did some godawful things to motors and chassis, but once in a while "got it right"...usually in spite of myself, and I suspect that a LOT of people got tons of enjoyment from trying to fix the brand-new stuff they just bought

-john

[dc-65x]

Hi John,

Great stuff again .

Would you be interested in doing a late 1968 "open" 26D arm for trade goods and or payment . It would be for this project car:







The car handles fantastic but I haven't been able to come up an arm that was as fast as a 1968 16D open motor. Team Dyna
Rewind had some 26D cars they demo'd at an Eastern Pro race in Oct '68 that were as fast on the straights as the 16D's. That's what I'd love to have for my 26D project car.

What do you think John?

[havlicek]

Hi Rick,

Of course I'd do it. The arm in there looks like a surprisingly big wire arm and all the bulletproofing has been done (and then some!...are those 36D brush tubes?) so it's just a matter of you giving me an idea of how hot you want to go. I'll PM you for the dirty details.

-john

[wilbor56]

hi John bill here from nj while sitting in my chair this weekend having my first cup of coffeeeeee the mail man came to my door with my normal stack of bill's keep telling him im not that person but it dont work, any ways much to my delight was a package from you so knowing in great antispation knowing what contents await me i began to open it. (you are a sick person using that much tape and taping the bubble rap as well sick sick man ) any way's 30 mins later and a wide use of power and non power tools i was able to finaly make my way to the prize inside and all hard work and stress was well worth the effort, (which is pale compaired to the effort you put into winding of this arm) now my problems are 2 fold one how to hope to acheve such a high lev of workman ship and second when the time comes finding the proper build to set this is but that is for another post. again thank you much for that and im going to be sending you some arm's back to do as you wish with.

bill harris

[havlicek]

Hi Bill,

Of course the pleasure is all mine. From checking what I have here, that appears to be the last arm I had that was soldered instead of welded so it could only be a casual runner at best anyway. Although a big wire arm like that is going to be anything but "casual". When you get going with winding please add to this thread any questions or finished arms you have. It was never my intention for this thread to be a "John thread", but a place where people could get together and share what they know and what they've learned about "the black arts"...NOW, not what they heard or did then From my perspective, winding/rewinding is "the final frontier" of the retro movement and I'd love to see a resurgence in this aspect, even if it is only a relatively few people. People are scratchbuilding, painting bodies, doing all kinds of crazy designing and testing, now if only...

-john

[dc-65x]

Hi Rick,

Of course I'd do it................

-john

WEEEEEEEEEEEEEEEEEEEE!!!!!!!!!!!!!!!!!!!!!!!!!

Thanks John! PM sent

Rick

[havlicek]

...this is gonna be fun!

-john

[Ed Miller]

John,
The arms that you wind for us are the best,you can tell you take pride in your work. Can't wait to get these in some fresh setups.


ED

[havlicek]

Many thanks Ed, and it's a pleasure working with you on this stuff.

-john

[wilbor56]

you will see that i posted this same question on a diff topic but here goes again. i have noticed that their are diff comms made up of
diff # of segmants can you explain the diff in these and some of the problems that you might run into when winding a arm with more than 3 segmants in the comm.

tks
bill harris

[havlicek]

Hi Bill,

If a comm has say five segments, the arm will have five poles. A comm segment is there to energize a particular pole when it comes in contact with a motor brush. As the number of poles increases, the physical space occupied by each pole becomes smaller making things really tight. Working on the comm and the arm itself seems like it would be a real PITA, but I have never rewound a five-pole motor.

I believe there are also different winding patterns and sequences available when you get into five-pole motors, but I honestly don't remember for sure. The three-pole motors are hard enough as it is, so I figure why torture myself any more than necessary.

[havlicek]

Back on to my Champion FT16D project. For this one I may just do two arms, one can drive and one endbell drive. Anyway, I decided to use an old Pooch #26 awg wind I wrote down from some thread I saw here as my starting point. I had to guess as to the comm timing... so I went pretty high but not stooopid-high.

I used a Tradeship blank but with a big-honking Kirkwood comm since there's plenty of room in the Champ endbell... a good thing, who knows? Of course, for this one I "welded/brazed" the comm connections as it should be a pretty hot arm.

Anyway, the arm shaft had to be polished down maybe 1 or 2 thousandths to be a snug fit without having to force it in and out of the bearings I installed. That part was probably as tedious as winding the arm, but the arm slides in and out of the setup with a little pressure and the end result is a really nice "precision fit". I used the "higher temp" #26 wire I have here figuring this might be a good idea in this motor. Just a couple of minor details to take care of before I can spin it up.

[havlicek]

I don't know... maybe those Pooch guys gave away a free blast-shield with every motor. The #26 (at least on the Tradeship stack which is a little on the short side) is a scary arm, coming in at .2 ohm and drawing over 3 amps with Mura medium springs. I might be able to get that down a little, but this seems like a really hot wind... maybe a little over the top.

[wilbor56]

If it is over the top you just have to raise the roof a bit then it is not over.