3573 replies to this topic

[havlicek]

What about coating the stack prior to winding, any thoughts?

... Steve O'Keefe (who showed me some awesome looking arms he did!) and I both came up with the same basic solution for this...high temperature paint like they use on exhaust pipes and barbeques. I use a brush-formula and do two coats right over the powder coating baking for each coat and I think Steve has used a spray formula. These materials are cheap and easy to get at any auto-parts store or even hardware store. Of course, this epoxy should be great as well but a bit more time consuming. If the arm blank is powder coated in the first place, simply not tugging too hard on the wire will probably work but those sharp corners at both ends of the stack are dangerous for the first layer of windings even with the powder coating.

-john

[Slapshot]

Coating for blanks. I won't tell you what famous arm winder told me this from the old days. For now I will blame "Insert Blank" for this. (No really thats his name).

Ceramic Glazing compond colors for pottery. Liquid paste glaze works best but dry powder will work but takes more effort to apply (pre heat). Heat cure or bake to arm slug at hi-est temp on your oven or nearest to what bottle says. Some are low temp glazes thats the one you want. For Hi temp glaze you may need to additionaly final cure in which you phaze it with a blow torch. Colors usually are different uncured but when fired come out the desired color. Withstands whatever you can throw at it. I have seen them at pottery stores in 1oz bottles in many colors but look around.

I know your going to say this is steel your talking about but it sticks if heated correctly.

Raymond

[havlicek]

Boy Raymond...there's a great idea I never would have thought of. Might be worth a try for sure...thanks!

-john

[Steve Deiters]

All this talk about rewinding got me thinking. Anyone remember the "starwinding" technique for rewinding armatures? I remember reading about it in '65 or '66 and giving it a try.

[don.siegel]

Yep Steve, that rings a bell! Wasn't that winding each pole, but leaving the wire loose at the end then joining the three loose wires in a "pigtail"? I think I tried it at the time, but don't remember how it performed... Seems that it was good for low-amp tracks...

If Rocky is hanging around, I'm sure he knows about the star wind!

Don

[stoo23]

Hey Hi there, ...Nice Work !!

An Older slotter drom Sydney, Oz,..also used to Really enjoy Winding my own arms Many Many years ago.
I remember having One particular #25 that Won me a Few races and was a Lovely arm !!

The Ceramic concept Really works!

Waaay Back when still Running 26d's and Melting Many endbells,..lol,..Who Didn't,..
I was trying and running some pretty Radical Winds and an engineer friend of the Family (who built a static Balance device for me), had a wife into Ceramics and He suggested we try it.

Sure Kept My 25 of 25's running,..Until the endbell Melted !!,..lol,..I remember it Made a Sound like a Bob Green Open !!!,..lol

Some years back though,..I went looking for a suitable Armature Winding 'Glue' as such.

I did a bit of research and actually found a Very High Strength and Hi Liquid Holding Power,..(IE it Remained Gooey When initially Liquid and would Not 'Spin Off'), form of Polyamide Varnish like Resin,..That Required Pre Heating and a Not so dramatic Cure. It Remained Stable till about 412 or 420 from recollection.

I had also Figured that at Temps around the 350 to 400 degree points,..Failure of the Epoxy was Probably the Least of My Worries.

I am Sorry that at the Moment I cannot remember the Name,..But it Did Hold together on the Few arms that I tried it on some Years back.

Getting Good Welds on The Commutator are Probably More of an issue !!,..lol

Now you have made me want to Wind a Few Arms again !!,..

If I can Recall a Brand or Product Name for the Material I found,..I will Post it here.

Star Winds??,..Hmm,..from My Recollection,..they were a complete Waste of time and effort and as far as I am aware came More from Multi Pole motors than the simple 3 spoke ones we use. None that I ever saw run went as Quick OR Quicker than a well wound standard Wind!

Cheers

[havlicek]

This is the first arm I've done in a while using #25awg on a New Mura blank. I've had some difficulty working out a pattern on the Mura blank with #25awg in the past on this blank so I spent some extra time working on that aspect. This is also the first arm I've epoxied using Cotronics Duralco 4461 which is rated for 500° F. This material has really nice working characteristics and seems to really penetrate the windings fully. Anyway, the arm comes in at around .2 ohm and spins like a sonofagun. I'm also down to using 1/32" and 3/64" drill bits for balancing to add a safety factor with these arms since the web profile is thin. Finally, this particular arm was spaced so that there's enough shaft for it to be either can or endbell drive depending on what use for it someone has. It's a "whistler" , I want to say it's a "rocket"...but that one's been taken


-john

[Tex]

Looks great, John; keep up the good work. I hope to try my hand at rewinding in a year or so.

[havlicek]

Thanks Stuart and Tex. I say go for it!, and if there's anything I can do to help just let me know. Winding can be frustrating as heck, but it can also be a huge kick when you get one done and hear the thing spin. You can get gobs of torque and RPMs out of these things...make them as mild or as wild as you please.

-john

[havlicek]

Here's another new Mura blank done-up as a #23 awg...for the not-too-faint-of-heart :-) Epoxy is (again) Cotronics' "Duralco 4461" cured at room temp for 24 hours and then post cured for 15 minutes at a time (x3) at 200°F. The #23's are the only ones I'm afraid to spin-up all the way with no load...they sound scarey



-john

[JerseyJohn]

Now thats what I call Horse Power John!!!!!

[havlicek]

Now thats what I call Horse Power John!!!!!

Hi John,

Yeah...I wouldn't run it for extended periods of time , but for blasting around the track a little or maybe slot drags the 23's are pretty crazy. They feel like they want to twist out of your hand when you spin them up. There's at least a "bit" more safety with these and the Duralco epoxy and the thinner drill bits for balancing, but with this one, I went for the gusto. I also coated the arm with Duralco before winding.

-john

[havlicek]

So I started a little "project" a while back cutting-down a Mura "VTC" can. I took the whole endbell part of the can off, the part with the tabs and screw holes for mounting the endbell which shortened the can by a pretty good amount. This made drilling the endbell for the can screws a little difficult since the endbell hardware screws were pretty much right in the way, but I was able to get them in there OK. I think it was Phillipe that said something like this was available from Mura for a while...maybe for 1/32 cars or just chassis where space is a problem. I got a suitable arm wound from some older Mura blanks with short stacks and some Blue Dots in the can and am just waiting for the epoxy to cure. I'm going to balance it and give it a spin after work to see what's what. It all looks good, but who knows how these things will turn out?...not me

-john

[havlicek]

So I got the arm all done up and it really screams, drawing around 4 amps @ around .2 ohm. The can is a cut-down Mura "VTC" with Mura Blue Dots and the arm is a short stack older Mura drill blank with the thinner laminations (.007") and a Kirkwood com wound with #25 awg, with the wind inspired by Ron Hershman. A normal Mura C can is pictured next to the cut-down one for a sense of scale, with the arm below. 1/32 sidewinder or anglewinder possibilities here. Not long ago, Jairus built a beautiful 1/32 anglewinder that would be about perfect for something like this...I think.



-john

[havlicek]

I have 6 arms here of varying winds, stack lengths and timing (some are pretty mild and some are pretty wild) that folks can have for a small fee (pretty much cost). The reason for this is that I never kept a record of which ones have the high-temp epoxy which I'm using now. Some are useable for either can or endbell drive, some are can drive only. I'm not sure if this is the right forum for this, but if anyone's interested they can just PM me for details.

-john

[havlicek]

...for those who've asked, here are the arms with my scribble for the specs next to the decidedly amateur photos.




-john

[Michael Rigsby]

Beautiful job of armature winding there sir. My hats off to you. None of mine I ever did years ago looked that good, and I doubt I could do it today even though I know a lot more than I did. When you say they are Mura blanks, does that mean that Mura supplies blank "unloaded" arms with comms already on them?

Michael Rigsby

[havlicek]

Beautiful job of armature winding there sir. My hats off to you. None of mine I ever did years ago looked that good, and I doubt I could do it today even though I know a lot more than I did. When you say they are Mura blanks, does that mean that Mura supplies blank "unloaded" arms with comms already on them?

Michael Rigsby

Thank you Michael. I still would like to continue to improve, but have at least gotten to a level of consistency and have figured out some winds I prefer. On the arms, yes... I've been using Mura blank arms and buying their coms separately to be installed for overall arm length and timing. I also have gotten hold of some older Mura blanks from time to time with Kirkwood coms. The older blanks are really nice as well...but I prefer the new Mura comms to the Kirkwoods. Lastly, I've gotten some good advice on sourcing parts and also on some winds from SlotBlog (especially Ron Hershman) that made it possible for me to revisit one of the best aspects of slot cars I remembered from when I was a kid. If you're thinking about maybe doing some winding, go for it!

-john

[Phil Irvin]

Back in the 60s when I wound my own. I found that if I measured the length of wire, rather than the number of turns, I came out with a better balance. I had no meters to test the arms resistence so I could not tell if each poll was right on. Back then all I had was static balanceing. One thing I did do was make a ficture to rotate the arms slowley over a 100 wat bulb so as to not let the epoxy gravitate to the low side..I can't remember what kind of epoxy I used but it was used in large coil windings and it had a slight caramel color. My book on what lengths I did is lost in my many moves. I too did a 23 guage on the champion setup with the hi temp red ends that was an amp sucker on the track but was real good on the drag strip with a deep cycle battery.

SPENT A FEW LATE NIGHTS
PHIL

[havlicek]

Back in the 60s when I wound my own. I found that if I measured the length of wire, rather than the number of turns, I came out with a better balance. I had no meters to test the arms resistence so I could not tell if each poll was right on. Back then all I had was static balanceing. One thing I did do was make a ficture to rotate the arms slowley over a 100 wat bulb so as to not let the epoxy gravitate to the low side..I can't remember what kind of epoxy I used but it was used in large coil windings and it had a slight caramel color. My book on what lengths I did is lost in my many moves. I too did a 23 guage on the champion setup with the hi temp red ends that was an amp sucker on the track but was real good on the drag strip with a deep cycle battery.

SPENT A FEW LATE NIGHTS
PHIL

Hi Phil,

It's great to talk with another "mad-scientist" winder from back then. My favorites were the Mabuchis and while my friends liked the Russkit and Classic motors, I liked the yellow things that I think (memory is fuzzy) were sold by K&B??? I think they were called "Wildcat" and "Bobcat" or something so someone correct me on that. Of course they were all pretty much the same, but we were all doing some crazy stuff and having great fun.

Here's the thing; we also debated about length of wire versus number of turns as a methodology but then as now I came to a different conclusion altogether. Keeping in mind that whatever method we chose, the last wrap had to end at the commutator tab...the most important thing for me was to practice "patterns". If you chose to go by length of wire and your patterns varied from pole-to-pole, you might wind up ending at the bottom of the stack on your last wrap. Working out "patterns" that you could duplicate from pole-to-pole would assure good consistency as far as length and resistance. Those "patterns" would include things like how many turns for the first, second and third etc. "layers". The number would change from layer to layer and "how far" you went over the previous layer...end before or after the bottom layer's last wind etc. They also would include how and where you would make your "turnbacks" (the method you use to change directions at the end of each layer and start winding back in the opposite direction) and even how you ended at the com tabs (you could simply run over the tab, do a complete "loop" around each tab or cut the wire at each tab and start a new length of wire for the next pole). This got a bit more difficult with double winds...I don't think I ever did any triples (quads anyone?)...as there were more things to consider.

On the epoxy, the stuff that you could simply buy in the hardware store (Elmer's etc.) seemed better than what is normally available now and I remember thinking it had a vaguely "peanut butter-ish" smell to it. It seems now that most commercially-available epoxies (Devcon etc.) are more geared towards easy working and curing rather than strength and heat resistance. I also recall some white and grey-ish epoxies that seemed to have even better properties but I always thought they made the arms ugly as hell. I know it sounds stupid now to even care what color the epoxy is, but I wanted them to look nice anyway I always baked my arms which causes the epoxy to at first become much less viscous and flow into the winds better...as well as speed-up the cure and increase the hardness of the final cured product, but quickly learned that you need to babysit the arm and flip it every little while to prevent the whole mess from running out one end of the arm

For balancing, Rick here (R Geo Products) recently made me a one-off balancing block that is wonderful and allows for greater precision and better results than using a wood block or worse yet...a lump of clay to stick the razor blades in Of course now we also have things like Kevlar to tie the arm with and even (with a lot of looking around) high-temperature epoxies...not to mention endbells that don't melt on command.

Steve O'Keefe ("arodyn") here has done some beautiful winds he showed me some pictures of...not unlike his amazing chassis builds (see the "puzzle pan" build) and Ron Hershman and others have really good info on wind specifics they're all too willing to share, as opposed to the secrecy my buddies and I practiced back then when one of us stumbled on something that actually worked :-) Pablo and others have also done some winding recently so if you choose to try your hand at it again, there's still plenty of info around and helpful people willing to share it right here on Slotblog. Thanks for sharing your memories about winding!

-john

[Phil Irvin]

I did a double 32 for 1 track I raced on that had LOUSY power. It ran away & hid from a full track of racers but qualified lousy. Usually had to work my way up. It never ran hot. I ran it so much there I wore the comm out. Never did another. Tha track finnaly went to 2 deep cycle batteries used in golf carts. Then came a few 27 & 28 guage on a Mura .007 lamanition .460 stack with 35 deg. timing.They did good as long as I had the Mura brushes with the pig tail (shunt cast in). I had a unimat 3 jaw lathe to cut comms with....wish they had diamond tip tools back then BUT....I made a jig to mount a Dremel with a FINE stone to grind the stacks. Worm clamps can do wonderfull things....Found a speed control at Grangers to slow the Dremil down. Worked wonders.........

MAN..you opened some old doors. (memories)

61 & called a rookie,
PHIL

[havlicek]

MAN..you opened some old doors. (memories)

...yeah, I can almost smell the melted plastic

-john

[Phil Irvin]

I ain't got enough fingers & toes to count on..........

PHIL I.

[havlicek]

I just finished a nice #26 awg on an older Mura blank with a Kirkwood com. I have to balance it tomorrow after the epoxy is post-cured in the oven, but this was one of those arms that just looked kinda neat (I think).



-john

[JerseyJohn]

I just finished a nice #26 awg on an older Mura blank with a Kirkwood com. I have to balance it tomorrow after the epoxy is post-cured in the oven, but this was one of those arms that just looked kinda neat (I think).



-john

that sure is purdy John