3573 replies to this topic

[Prof. Fate]

Hi,

My first rewinds were fice-pole Pittmans... a failed attempt to make a high speed Pittman 704. The motor wasn't a failure, I could just get a can to go faster. In those days I did 5-7 poles, even putting Pittman arms in Mabuchi cans.

There is no real difference in winding or the approach to my mind.

One of the more interesting Mabuchis was from Tradeship in '64 or '63: a five-pole version of the Revell SP500. In parallel, Strombecker's line of Pittman 196 lookalikes included both five and seven pole versions. All of them got rewound then.

Fate

[wilbor56]

jeee prof are we dating our selfs. any way thank your for the respones i have no intentions of trying th 5 arm comm was just curious about if you have to use a diff pattern to wind and what the over all effects would be on timing somthing like that. again thank your for your response.

bill

[don.siegel]

Hi,

There is no real difference in winding or the approach to my mind.

One of the more interesting Mabuchis was from Tradeship in '64 or '63: a five-pole version of the Revell SP500.

Fate

Hi Rocky,

I never tried winding one of the five poles, but if I remember the period articles right, you were supposed to wind two poles at a time, and overlap them - so more complicated than a 3 pole! Maybe if Larry Shephard is around, he can remember this.

I think it was Aristo-Craft that sold the five-pole Mabuchis; very similar to the Revell SP500 can, and just about as slow, maybe slower... I always thought it was funny they would do a five pole arm in a cheapo can motor! I don't remember these from the period at all, but picked up a couple in my collecting career - and had one in a car for awhile before I realized it was the 5-pole model!

Don

[Hworth08]

I've rewound one five-pole arm, what I believe was a DC-65 arm that was shorted.

I was careful do make a sketch of how the wire came off so I would rewind using the same pattern. On this five-pole blank the wire "jumped" a stack. Instead of finishing a segment and then winding the next segment, the wire bypassed the closest segment to the next one. It felt pretty strange but was actually quite simple and there was plenty of room for the wire as each pole only had about 25 turns.

I'm fairly sure that Pittman wound at least some of their arms before the comms were installed, then twisted the correct wires together and welded the wires to the comm. I wound mine using only one peice of wire but when I was finished I could see that the Pittman method would be easier, if you connected the correct wires!

It's sort of hard to believe now but the Pittman style motors were faster than the Mabuchi can motors for a year or so after the "tin can" motors were released.

[havlicek]

Don & Don,

Either of those sounds vaguely familiar and similar to what I was referring to, but I seem to remember the "alternate" wind thing where you wind from pole one to pole three, pole two to pole four, pole three to pole five. It could also be that there were several sequences you could do including straight "series" wind. Just looking at the arms, the space on those poles do look pretty tight though. No matter anyway, I never wound one back then and I'm not about to start now

[Prof. Fate]

Hi,

You are right, you go across two poles. I just didn't find it more tedious to do the wind.

I might be skewed in this as my dad was an electornic buff and had all the bits on hand from the beginning for me in the '50s. It was considered normal for me to wind a motor to suit my needs.

In some respects, the early Mabuchis were like the modern ones, in that Mabuchi was winding for industrial needs, usually toys, and we were just a side issue.

My first can was a 15R Mabuchi in a Stromberker in '62 that blew and I rewound it. The stock wind was ca 250t of 34 wire and "rated" at 12 volts/15,000 RPM. Again, much like the modern Ninco NC1 "S" can (FC130FC).

P will like this: I ended up putting it in the Cooper Indy so that I could beat my dad on our home track!

It wasn't really an issue, i.e. hot arms, until April '64 in the small town I was in outside of Seymour Johnson AFB. THEN it was obvious with the higher speeds that I could wind cans to beat Pittmans. So, I had no "Pittmans faster" phase. My first Mabuchis for commercial tracks started as rewinds.

On the Tradeship and Pittman five-poles, I never could find the supposed superiority others claimed. Even rewound.

Fate

[havlicek]

Here's an arm I did for Rick that is a complete question mark and even if it fails (!?), I figure it's more honest to post my successes as well as my umm..."less-than-successes" Anyway, I needed to come up with a blank that either was can drive or where the shaft could be pushed through for can drive. Pushing the shaft (at least with my carpenter's tools) sometimes works and sometimes doesn't work, so right there was a problem. I took a Tradeship blank and of course I couldn't push the shaft...Murphy's law right? So I:

Disassembled the arm taking all the laminations off there and then did my best to flatten them and run each side of each one on a piece of 320 sandpaper stuck to my glass work surface with my fingertip.

I then reassembled them on the original shaft which was now out of true from trying to push the shaft too hard so I could slip the whole thing into my "press" (really a small vise with holes drilled horizontally through the top of the the jaws) and be sure the lams were as flat as possible by applying pressure to the assembly.

I then did the final assembly of the "new arm blank" on a new shaft, clamped it and applied high temp epoxy to the insides of the stack to act as an insulator and help hold the whole mess together.

Then I epoxied the insulators to the ends of the stack, and trimmed them flush to the stack after the epoxy was cured.

Did a polish job on the stack which took way more effort than it would have on the original stack.

I finally added a com and tail spacer as well as a Kirkwood com epoxying them all in place with the com timing set.

...all of this to get a can drive arm blank and after an embarrassing amount of time spent and I still hadn't wound the arm Anyway, I figured out a MUCH better way to do all this if I have to do it again, so at least I will have learned something from this battle So the idea here was to do a basically "open" arm for a 26D that's been bulletproofed. Anyone who's wound one of these things will confirm that there's not much room at either the top or the bottom of the stack because of that stubby can. Up top, the normal Tradeship com helps because the tabs don't hang below the com where you need all the room you can get. At the bottom of the stack, you need to keep things tight so the coils don't hit the rear end of the can Since I used a Kirkwood com with those gigantic "hooks-for-com-tabs" that hang below the com, space was even tighter than normal. At the bottom, things got fairly tight too because this is a #25 wind and it's more difficult to do big wire arms using all the available space. Anyway, I got the thing wound, welded com connections, tied, epoxied, balanced, cut the com and sent it out without even trying it since I don't have a working 26D setup here. It meters OK (no shorts and the same resistance on each pole) and comes in at somewhere around .2 ohm so...???

I know it sounds ridiculous to spend that kind of time and effort on an arm that may not even work...but I learned some things along the way and there's value just in that! So regardless, I figure it was worth it. Anyway, here's the result:



-john

[Don Weaver]

Hi John,

When you need to move the laminations on the shaft have you tried to put the shaft under a little bit of pressure and then heat the laminations from the outside and let the heat travel towards the shaft??

Don Weaver

[havlicek]

Hi Don,

Yes I have and sometimes that helps...sometimes (I suspect because of either too much heat causing them to expand or because the heat hardening/changing oxidation) it makes it worse. What I think is the best solution (assuming no machine shop tools for pressing) is to simply cut the shaft off flush with the end of the stack and press it through with a slightly smaller diameter drive pin and be done with it. It seems the most direct way as well as the one least likely to distort the laminations. I've had some luck doing that even with .007" lams...but even that is hit or miss. Thanks Don.

-john

[dc-65x]

MINE!




Thanks John!

[havlicek]

...the pleasure was all mine Rick

-john

[wilbor56]

bill from nj here: well this weekend i finished my first 16 wind ever and well i have named it ugly ducking 1 but just wanted point out one small detail that i didnt think of when you wind the first leg of the arm you want to go 1 turn short of your goal ie was doing a 45 turn (as per john's recomdations) so on first arm you want to do 44 that way when you are finished the other 2 legs you you can finish the last turn and connect the wires back together with out having one leg with 46 turns. so any way i will be posting a photo soon of the arm just have to get some epoxy to coat the arm with i did take a ohm reading and found it to be 2.7 ohm's so will post photos and up date when i put it in a can and power it up. (takes out fire control devices)


bill

[havlicek]

Hi Bill,

From what you posted, I think we're using two different methods (and there are many). I start at a com tab and go over the next pole (either CW or CCW depending on which way I'm winding) and then drop down to start my first turn. When I have that pole copmpleted, I come up on the last turn and come over the stack I just did to the next com tab and then drop down over the stack to start winding that pole. My wires aren't broken and only the last com tab will have two loose wires to connect. So the wire is all one long unbroken piece that I strip at the place it passes over each com tab. The last turn (in this case #45) is the one that, after coming up and over the stack (a full turn), gets connected to the next com tab.

-john

[wilbor56]

i was using 1 contunious wire just got confused at the end i do that alot the older i get. confusion is becoming a every day occurance any more lol. i striped it down and going to rewind again was not happy with the way it came out. did you recive the arms i sent you just checking to make sure the mail man is not a slot fan and keep them for him self.


tks
bill harris

[havlicek]

confusion is becoming a every day occurance

Hi Bill,

Welcome to the not-very-exclusive-confusion-club...I'm a charter member. Problem over here is that I've been that way since I was young

did you recive the arms i sent you just checking to make sure the mail man is not a slot fan and keep them for him self.

...got 'em and I did reply somewhere either on a thread or a PM that they came but I can't remember where (see my answer above re: confusion)

-john

[wilbor56]

WOW just figured out what you were saying about how you start your wind im going to try that it makes more sense and now that i think of it, it's all starting to come out of the deep dark receses of my mind. (that is a scary place for me to be again) but you are right it make a ton of sense to start the wind that way. sorry for being a bit slow on the uptake.


bill harris

[wilbor56]

Well, here are some photos of ugly duck 1. Not for the faint of heart...

[wilbor56]

Still have to solder and test run before I coat it. This one came in at 2.63 ohms.

[havlicek]

Hi Bill,

You're on your way!!! It really doesn't look so ugly to me, and I've seen arms that looked worse that run great. Couple of things:

1)How did you set the timing, it could be an illusion but it looks crazy-advanced?

2)2.63 ohms sounds strange and an arm done with 45T of #28 awg should be in the .3 to .4 ohm range. Maybe you meant .263 ohms and if so, you must have one heck of a nice meter to read that accurately! Did you check for continuity between the com segments and the shaft and/or stack...there should be none (one probe touching a com segment and one touching the stack or the shaft).

3)If you solder the com tabs, you should be able to give it a slight spin at low voltage with absolutely no problem. A good way to see what's what before you epoxy it.

4)The arm looks balanced, but isn't epoxied yet. Balancing should be the last thing you do to the arm...for sure it should be done after epoxying

Great work Bill, please post more pix when you get them.

-john

[Michael Rigsby]

Just eyeballing it, looks to be around the 38* timing area. Should be a screamer.

Michael Rigsby

[Horsepower]

Looks better than my best work!

[havlicek]

Ed Miller asked me to try a little experiment...rewinding an SCX RX-42. When I got the motor, I tried it out on the power supply and it was pretty anemic alright. Still, it reminded me of a sort of an updated smaller FT16D so I approached it like a Russkit 22. There's a slightly weird-but-serviceable endbell, a skinny/short can, a decent looking arm and com in there so I went in to see what's what. Magnets seem actually OK for the skinny things that they are, certainly as good or better than the stock Mabuchi magnets of old. I did a #29 wind that draws a bit less than 1 amp (original was like #31-ish...maybe a metric size and 200 or so turns!) and the little bugger actually sounds really good! It's a neat little package and I think there's more potential if better springs can be fit and maybe there's even stronger magnets that would work. Going all-out and also doing bearings probably wouldn't hurt either and for relatively little money you'd wind up with an appealing little motor that would fit in some tight spaces.



-john

[wilbor56]

UGLY DUCKLING; update well yesterday after a hard day at work (ya right) i when home and sat their looking at my creation admiring the fruits of my labor and then all of the sudden it came over me like a 5 year old on Christmas's morning the need to know. so with great haste i ran down to the slot cave (aka basement) flipped on the power switch to my work area and to life my work bench came. then humm to find the right can so the search began and then finally their it was like a bright light standing out in the black hole that i call a work bench i found it so with great haste i began to tear the old can apart and freshen it up. so a fresh set of bushes realigned the hood and Finlay in went the ugly duckling into its new home. then with great care put it all together and then sat their wow i had done something i had not done for 20+ years and finally the moment of truth had come so i flipped the switch on the power supply and added voltage up to went 5 volts thought this would be a good starting point to breath life into this beast but this sudden wave of failure comes over me nothing silence humm what had i done wrong then i though mabey all it needs it a little smack on the bottom something like a new born that little smack to help it clear it lugs for the first time and yes after a slight twist of the arm bammmm
to life it jumped humming along at delightful pace seaming content yes to borrow a line from a van helsing movie (IT'S ALIVE) so after a min or so chest puffed out with this feeling of elation victory of man over machine i basked in the glow of success. then it hit me then age long battle of good vs evil you know CRANK IT UP--- NO DON'T DOT IT FINISH IT FIRST---NO CRANK IT UP well you can guess which one won that argument. so with a twist of the wrist up went the voltage 12 volts and mother of god did the motor respond with the sweet sound of that high pitch wine ahh music to my ears well short lived it was first a little puff of smoke followed by a billowing cloud of smoke and then silence nothing it's life all be short was glorious. well needless to say the ugly duckling not resembles roast duck, duck flambé. oh well but lesson learned that yes i could rewind a 16 and get it to run now we work on improvement.

Bill harris
killer of the ugly ducking

PS stay tuned for the sequel UGLY DUCKING 2

[John Secchi]

John
The magnets in the SCX motors are realy quite good, not sure they would work with a 25 gauge arm though but good enough for milder use.
Been fitting them into old Johnson 13uo cans [some fit, some don't!] and winding 130 x 38swg [approx 0.15mm] with only enough advance for the direction i wanted it to turn, good for 1/32 scale racing and giving them old Scalex cars extra legs!
[oneofwos]

[sidejobjon]

Anyone know tjet pancake winds? I been fooling with 11 ft # 36 each pole.
Thanks John Falzarano