# Winding your own armature advice



## Dyno

I have been wanting to try winding up some of my own T- Jet armatures for a while and finally decided to give it a try. Ive spent countless hours looking for information on this subject, (there doesnt seem to be a whole lot of info out there) along with talking to a friend who winds his own drag arms. He walked me through the whole process and I understand it totally, but my question is what gauge or gauges of wire are suitable for road racing? Im looking for a good combination of torque and top end hp, maybe 4 or 5 ohms? Something a little hotter than a mean green. I only home race, so following any class rules isnt important to me.

Thanks,

Dyno


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## slotcar58

If you want something hotter an a mean green try 37 or a 38 double wind (like a Super II). I believe 36 would be too hot for a non-magnet car. Good luck!


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## T-jetjim

HO World has a How To rewind T-jet arms:

http://howorld.net/archives/howto/rewind/armature.html


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## Dyno

slotcar58 said:


> If you want something hotter an a mean green try 37 or a 38 double wind (like a Super II). I believe 36 would be too hot for a non-magnet car. Good luck!


Thanks for the advice. I have several Tjets with Neo mags on the bottom of them so I might have to try both winds. I should be getting the wire today so next stretch of free time I get I will report back with my great success or miserable failure.

Dyno


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## Dyno

T-jetjim said:


> HO World has a How To rewind T-jet arms:
> 
> http://howorld.net/archives/howto/rewind/armature.html


Thanks for the info, Im shocked I didnt run into that article before. It basically summed up what I already knew but added a few more tidbits of info.

Dyno


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## joegri

dyno yer way braver and taleted than i . to take on this task ya gotta have good juju on yer team. i dont have any advice but i am watchin what ya got going. i do have an interest in what you,re gonna try good luck! as far as hypo arms are concerened i just got a custom wound arm from tjetsgrig/jim it,s over the top smooth and fast.hope yours come out well !!


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## Dyno

joegri said:


> dyno yer way braver and taleted than i . to take on this task ya gotta have good juju on yer team. i dont have any advice but i am watchin what ya got going. i do have an interest in what you,re gonna try good luck! as far as hypo arms are concerened i just got a custom wound arm from tjetsgrig/jim it,s over the top smooth and fast.hope yours come out well !!


I dont know if Im more talented... I just like to try and make my own stuff. I hear the first few you make dont run so well. The thing I do have on my team is a friend who winds stupidly fast drag arms showing me the ropes. He should be a huge help.


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## Boosted-Z71

I have wound a couple pancake arms for my T-jets, and they have come out very well, I want to start trying to work on some that would be Fray type legal, I have found that for the winding process a bobin tool like the fishing fly builders use works very good. There are types that have an extended tip & you can lay that wire wrap right in place on the stack easily, and it goes pretty fast. Does any one have a chart for the wire diameter & length required to produce a specific ohm after the pole is wound? if so I would really appreciate that info, also any tricks or tools to remove & attach the com plate would be appreciated. 

I made a crude little press to reform the tabs but you have to be soo careful, I know there has to be a better way. I use a brass sleeve to center the comm plate on the stack, then remove it afterwards. 

Also if anyone knows what to use to dye the armature stacks with, that information would be nice to know as well. I just got my first lamination stack done, checked the shaft & now after a little lathe work its near perfectly round. I may just paint this one on the ends but it would be nice to dye it like some I have seen. 

One other piece of advice from a novice for rewinds, I have had really good luck balancing my arms with epoxy afterwards, and they run very smooth, get yourself a watch makers poising tool, I picked up a really nice ruby jaw unit for $15 from ebay, Just take your time when you balance, I blow on the arm with a straw to rotate it. I practiced with modeling clay until I got the "expertise" & nerve up to start using the epoxy.

Boosted


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## usdra

http://www.wiretron.com/ this website has a resistance calculator you can download. Does not work with windows 7. After you figure out the ohms per foot (opf) 72% of that figure will be your reading at the pole. 37awg wire is .512148 opf. For this example we will figure a roughly 3ohm arm. opf.512148 x 9ft x 72%= 3.32ohms.

Eric
www.mobydiditperformace.com


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## tjetsgrig

Dyno said:


> The thing I do have on my team is a friend who winds stupidly fast drag arms showing me the ropes. He should be a huge help.


This fast?? This is one of my 2 laminate motors.......2 car batteries.


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## Boosted-Z71

usdra said:


> http://www.wiretron.com/ this website has a resistance calculator you can download. Does not work with windows 7. After you figure out the ohms per foot (opf) 72% of that figure will be your reading at the pole. 37awg wire is .512148 opf. For this example we will figure a roughly 3ohm arm. opf.512148 x 9ft x 72%= 3.32ohms.
> 
> Eric
> www.mobydiditperformace.com


Thanks that is exactly what I was looking for.

The vid on the drag t-jet is just sick, unbelievably fast, How many runs do you get on brushes & comm of that type build? I have no experience with any drag type cars, but that is impressive. 

How do you stop the thing without demolishing the car? 

Boosted


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## Dyno

Boosted-Z71 said:


> I have wound a couple pancake arms for my T-jets, and they have come out very well, I want to start trying to work on some that would be Fray type legal, I have found that for the winding process a bobin tool like the fishing fly builders use works very good. There are types that have an extended tip & you can lay that wire wrap right in place on the stack easily, and it goes pretty fast. Does any one have a chart for the wire diameter & length required to produce a specific ohm after the pole is wound? if so I would really appreciate that info, also any tricks or tools to remove & attach the com plate would be appreciated.
> 
> I made a crude little press to reform the tabs but you have to be soo careful, I know there has to be a better way. I use a brass sleeve to center the comm plate on the stack, then remove it afterwards.
> 
> Also if anyone knows what to use to dye the armature stacks with, that information would be nice to know as well. I just got my first lamination stack done, checked the shaft & now after a little lathe work its near perfectly round. I may just paint this one on the ends but it would be nice to dye it like some I have seen.
> 
> One other piece of advice from a novice for rewinds, I have had really good luck balancing my arms with epoxy afterwards, and they run very smooth, get yourself a watch makers poising tool, I picked up a really nice ruby jaw unit for $15 from ebay, Just take your time when you balance, I blow on the arm with a straw to rotate it. I practiced with modeling clay until I got the "expertise" & nerve up to start using the epoxy.
> 
> Boosted



There are plenty of wire gauge guides online, I did a google search and found plenty. I made a magnetic balancer out of a gear press that is rediculously sensitive. I only epoxy balanced once so far and it was ok, it was far easier to grind small slits and remove material with a dremel. I get mixed reviews on whats the better approach.


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## Dyno

tjetsgrig said:


> This fast?? This is one of my 2 laminate motors.......2 car batteries.
> 
> 
> YouTube - Aurora Outlaw Tjet Scale 1/4 mile




I dont know about THAT fast...lol I have to ask him.


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## Boosted-Z71

Yeah, I have a magnetic type balancer as well, but I prefer the poising tool. As for the method I was not sure which was best, grinding the stack or the epoxy method. I am waiting to see how the trued stack setup turns out in terms of how close I can get the air gap to what I want. 

Boosted


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## tjetsgrig

Boosted-Z71 said:


> Thanks that is exactly what I was looking for.
> 
> The vid on the drag t-jet is just sick, unbelievably fast, How many runs do you get on brushes & comm of that type build? I have no experience with any drag type cars, but that is impressive.
> 
> How do you stop the thing without demolishing the car?
> 
> Boosted


Hey, thanks Boost!

I can get quite a few runs out of a comm. They will wear away on the trailing egde of the comm segments getting smaller with each pass. Once the e.t.'s start to drop off, it's time for a new motor! As far as balancing goes, I lean more towards epoxy, grinding the stack tends to change your magnetic field, in my opinion ( I've tried both ways w/better e.t.'s with epoxy ).

Jim Sgrig


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## Joe65SkylarkGS

tjetsgrig said:


> This fast?? This is one of my 2 laminate motors.......2 car batteries.
> 
> 
> YouTube - Aurora Outlaw Tjet Scale 1/4 mile




Crazy!!!!!:freak:


Jim you are the man!!!:wave:


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## Dyno

tjetsgrig said:


> This fast?? This is one of my 2 laminate motors.......2 car batteries.
> 
> 
> YouTube - Aurora Outlaw Tjet Scale 1/4 mile


Ok, I showed my friend your video and he was impressed. He has been out of HO drag racing for about 8 yrs, but at the time he was running .4teens at 54 mph.


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## tjetsgrig

Dyno said:


> Ok, I showed my friend your video and he was impressed. He has been out of HO drag racing for about 8 yrs, but at the time he was running .4teens at 54 mph.


0.4teens @ 54mph is very respectable for a 2 laminate motor!! My goal was to try and break the .3's @ over 60mph with a 2 laminate.......I have accomplished that. I will say though, I have gone considerably faster with one of my Custom 5 laminate motors.......unofficial ( not in a sanctioned event ), 0.299 @ 80.05mph.......with a Tjet!!


Jim Sgrig


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## tjetsgrig

Joe65SkylarkGS said:


> Crazy!!!!!:freak:
> 
> 
> Jim you are the man!!!:wave:


Thanks Joe!!


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## tjetsgrig

Ok, my winding advice? Lots of time and patience! Lay your wire out tight and flat, silver bearing solder.........and don't be discouraged if more than a few attempts are unsuccessfull. It took a long time for me to go this fast!


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## Boosted-Z71

Tjetsgrig sent you a pm on the arm

Boosted


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## hrnts69

Hey Guys, iam wondering whats the normal guage/length of wire for a 2.0ohm, and 1.0ohm Motor? Ive have a couple Mean Greens that i dewond and wanting to wind them about 1.0ohm for Drag Racing. Whats the wire combo to acheive this?

Also, are you guys going down to 22,26,30 guage wire? Or is that too big??

Thanks


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## usdra

hrnts69 said:


> Hey Guys, iam wondering whats the normal guage/length of wire for a 2.0ohm, and 1.0ohm Motor? Ive have a couple Mean Greens that i dewond and wanting to wind them about 1.0ohm for Drag Racing. Whats the wire combo to acheive this?
> 
> Also, are you guys going down to 22,26,30 guage wire? Or is that too big??
> 
> Thanks


Post 11 has a link to a resistance calculator & a formula for figuring out what you want to know. For the 1.0 ohm I use 34awg & for the 2.0 ohm I use either 35awg or 36awg. Never used bigger than 31awg wire.

Eric
www.mobydiditperformance.com


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## wheelszk

Boosted-Z71 said:


> I want to start trying to work on some that would be Fray type legal,
> 
> I'm sure mean 16ohm type, because rewinds or dewinds are not legal in fray. I'm just saying.


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## Boosted-Z71

Yes your correct, I should have worded that a bit different

Boosted


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## Brixmix

There NOT legal in ECHORR, Fray , The Quarrel, HOPRA, and UFHORA in the T-jet class


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## alpink

what ever sgrig says is good enough for me. I have seen him make the guy with the Sherline lathe very unhappy, in person. I have plenty of his outlaw t-jet drag cars and they are all ballistic. however, when it is time to let the smoke out, it might be rather fiery instead! LOL


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## Dyno

Well I drove through six inches of snow tonight to pick up the wire and an old Laganke armature winding tool. If time and the GF permits, I'm going to attempt my first wind tonight or tomorrow. I will post pics of my results either good or bad. Wish me luck...


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## Boosted-Z71

Good luck, just take your time, I measure wire length & count turns as well. 

Post up pics & info when you finish, nothing like winding one & hitting the trigger & see it go, But I will tell you I was sick to my stomach when a stock arm went up in flames the other day in one of my tweaked fray built chassis, It took forever to clean it back up, fortunately I got it apart before it actually melted the brush holes, still had to do a ton of careful scraping to get the remainder of the brushes out. That is the 1st one I have lit up in years, I think the house still smells, (read as wife not happy), bought lots of candles & air freshners today.

Boosted


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## joegri

i dig all this talk of arm wraping and such cuz i dont have an idea what you,re all talkin bout but it sure is interesting and always check for pics and new post! so wrap on dyno and best of luck.


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## Joe65SkylarkGS

joegri said:


> i dig all this talk of arm wraping and such cuz i dont have an idea what you,re all talkin bout but it sure is interesting and always check for pics and new post! so wrap on dyno and best of luck.



LMAO!!!! I seen Jim wind a little when I went to his place. Amazing procedure. He did it just to show me cause I never seen it done before either. 

I think you guys are wound up a little too tight yourselves!!!!


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## Dyno

How can I explain my evening except for frustrating, yet informative.

This first attempt took me 3 hours! I first tried 16 feet and change of 36 gauge for 5 ohms and I couldnt get the comm plate on. I then tried 13' 7" for 4 ohms. After winding each pole and flattening the wire with a flat head screwdriver I was able to fit the comm back on. I epoxied it in place and made sure my wires were clocked correctly. The next part is were everything went down hill really fast. I was trying to lightly sand the wire ends to remove the epoxy coating and wouldnt you know it, I broke the last wire, and unfortunately it was the rear wire that I couldn't unwind and reattach. So I decided to keep on going and practice the soldering of the wires to the comm and filing the solder. That was the easiest part of the whole operation. I checked the ohms of the poles and got 5.9 5.9 and 11.8.
I put it in a chassis with dash magnets and it ran. Not well by any means and got HOT fast. It then sputtered and died. I gave it a nudge and it ran again. Then it died with a tiny wisp of smoke. I pulled it out of the chassis so I didnt melt it and checked the continuity.....nothing. I learned a lot from this project, and Im more determined than ever to wind a real screamer. I need to run to my friends house and get som comm plates because I only had one and I wasted it in a hurry. I will take a picture tomorrow of try number 1 and post it here.

Dyno


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## Joe65SkylarkGS

Wow what a night bud.

I am sure you will get it. Even if it kills ya!!!lol


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## Boosted-Z71

I use the liquid flux cleaner or laquer thinner and just soak the wire ends to remove the coating.

Sounds like you had a really good one if that one wire had not broke on you.

Boosted


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## Dyno

Boosted-Z71 said:


> I use the liquid flux cleaner or laquer thinner and just soak the wire ends to remove the coating.
> 
> Sounds like you had a really good one if that one wire had not broke on you.
> 
> Boosted



I was wondering if there was a liquid to do it. I even thought that maybe the heat of the solder would vaporize it. I have a roll of 38 coming monday. I will give it a shot again. 

Here the picture of my first (in a line of probably many)
dud.


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## alpink

dyno, you can get acid flux at most 1/24 slot tracks and online. just be sure to clean it real good with lighter fluid, naptha or motor cleaner after use. in any case, wrap each wire twice on the pole(with a short tail that you will trim off after) before soldering. most times, scraping the insulation off the wire is NOT necessary. use a high quality silver bearing solder judiciously, if you are not already, try to chock the armature shaft(top of it) in a pin vise to allow you to solder all three poles quickly and easily. even just holding the armature upside down in a regular vise is OK. as sgrig has said, you have to keep trying until you get a system that works for you. 
Alan Galinko, Jim Sgrignioli, Bob Lincoln, Eric Hirt and many others have been custom winding armatures for decades and none of them were instant experts, although they all are now. I have tried it and just don't have the patience. so, I just order with sgrig and wait until the magical arm is ready. I have gotten custom arms from all the above along with a few others that I have lost contact with. I respect all these guys even though I give Alan a lot of grief. but he is a big boy with a good sense of humor and can take the ribbing. if I told you how I treat sgrig you would wonder why he even associates with me anymore... LOL !


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## Dyno

alpink said:


> dyno, you can get acid flux at most 1/24 slot tracks and online. just be sure to clean it real good with lighter fluid, naptha or motor cleaner after use. in any case, wrap each wire twice on the pole(with a short tail that you will trim off after) before soldering. most times, scraping the insulation off the wire is NOT necessary. use a high quality silver bearing solder judiciously, if you are not already, try to chock the armature shaft(top of it) in a pin vise to allow you to solder all three poles quickly and easily. even just holding the armature upside down in a regular vise is OK. as sgrig has said, you have to keep trying until you get a system that works for you.
> Alan Galinko, Jim Sgrignioli, Bob Lincoln, Eric Hirt and many others have been custom winding armatures for decades and none of them were instant experts, although they all are now. I have tried it and just don't have the patience. so, I just order with sgrig and wait until the magical arm is ready. I have gotten custom arms from all the above along with a few others that I have lost contact with. I respect all these guys even though I give Alan a lot of grief. but he is a big boy with a good sense of humor and can take the ribbing. if I told you how I treat sgrig you would wonder why he even associates with me anymore... LOL !



I have acid flux here and silver solder also. The soldering of the wires was a snap. I used a piece of trim wood with a 1/16th hole in it to rest the arm in while I soldered the poles. I wish I knew about the acid trick last night, it would have saved me a headache. Also, I wound the arm by hand because I didnt have a vice to hold the La Ganke winder, and my GF didnt want to sit in the basement and hold the end of the wire as I held the rewinder in one hand and cranked with the other :freak:. I have nothing against paying for a custom arm at all, its just that Im the kind of guy that gets great satisfaction in doing things for myself. I know I can do it. My friend is coming bye this week I hope and giving me a class. He said it should take about 25 minutes to do a simple 2 lam motor. I guess I need to speed things up a bit...lol


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## joegri

dyno you should be very proud of yerself! ya wrapped an arm that actually moved. that is an accomplishment all by itself. now go get,em killer. my money is on the 3rd try for a screamer!!! wrappin an arm n casting are places i dont want to go, i,ll leave that to the pro,s. good luck and dont look back they might be gainin on ya!


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## 2racer

I had a arm that was 18.3 ohms on all three points a wire came off the botom. After I resoldered it 0ne pole became 6.5 any ideas why?


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## Dyno

2racer said:


> I had a arm that was 18.3 ohms on all three points a wire came off the botom. After I resoldered it 0ne pole became 6.5 any ideas why?


I'm no expert here but I assume the wire that was re soldered was far shorter than it's original length thus lowering the ohm value.


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## Boosted-Z71

Dyno I know what you mean by doing it yourself & that satisfaction, I do all my own work on whatever it is, theres days at home that I have been everything from the guy maintaining the septic system to an emergency doctor. I too just want to do it myself. I just ordered an arm from TjetSgrig, It may very well be my fastest arm when I get it installed, I will enjoy it but it will also give me something to shoot for in my own winds.
Keep winding, it's the only way to get better is to practice.

Boosted-Z71


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## Dyno

Boosted-Z71 said:


> Dyno I know what you mean by doing it yourself & that satisfaction, I do all my own work on whatever it is, theres days at home that I have been everything from the guy maintaining the septic system to an emergency doctor. I too just want to do it myself. I just ordered an arm from TjetSgrig, It may very well be my fastest arm when I get it installed, I will enjoy it but it will also give me something to shoot for in my own winds.
> Keep winding, it's the only way to get better is to practice.
> 
> Boosted-Z71


This is what I plan to do...:thumbsup:


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## K.L. VanAtta

Hello Everyone,

I did a lot of rewinding of pancake and Tyco/Riggen inline arms back in the early 70’s when racing in the HOPRA events close to me. For a gauge to my success I had Randy Kemp of K & K racing to compare to; I did buy many K & K arms as at the time they were the best.

I didn’t do any drag racing only road racing, used 37 gauge and 36 gauge wire from Belden with at minimum 150 degrees C heavy polythermaleze insulation ( try PlanetEngineeres for single 1 pound spools of wire in many different insulations and gauges ) with an occasional 35 gauge, 39 gauge double winds, 39/40 gauge double winds, and 40 gauge double winds done for experimentation. My standard arm was a 10 feet of 36 gauge wire on a 2 lamination blank with a old T-Jet comm; would adjust from there if the track had long straights or needed more “punch”.

When winding an arm lay the first layer down nice and straight and packed tightly so that the next layer will not push through; do not extend the first layer into the curved area of the winding surface near the tip. Use only fingers and soft tools to move the wire into position or to tamp the wire down, the use of metal anything can lead to the scratching of the insulation on the wire and to arm failure. The second layer, and if possible, all further layers of wire should naturally fall into the “valley” created by the two wires below it. The “idea” is to produce the “ideal” arm with flat straight layers of windings. I’ve managed a few, they are very good and last a long time.

A word on balancing. Once you have a workable technique for rewinding down the need for balancing becomes somewhat less important. Being able to repeat the technique for the three poles introduces minimal variation in mass. Thus the choice for balancing becomes the removal of mass not the addition of mass. The amount of magnetizable material removed is minor when compared to the magnet field produced by the pole energizing. 

However the amount of mass one may add in balancing through epoxy can have on the overall performance of the armature could be significant. Increase in heat and a longer time to reach maximum RPMs are first to come to mind. Regardless of what balancing you did initially, after the first few runs or first race it’s time to rebalance because all those little wires have moved around a bit ( it’s good to epoxy coat the windings ).

My 2 cents worth.

Keith VanAtta


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## Boosted-Z71

One thing I recently started doing to help with balance is to balance the comm stack prior to winding, By means I am no expert here but it seems to make the final job much easier as was mentioned prior.

Boosted


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## Dyno

K.L. VanAtta said:


> Hello Everyone,
> 
> I did a lot of rewinding of pancake and Tyco/Riggen inline arms back in the early 70’s when racing in the HOPRA events close to me. For a gauge to my success I had Randy Kemp of K & K racing to compare to; I did buy many K & K arms as at the time they were the best.
> 
> I didn’t do any drag racing only road racing, used 37 gauge and 36 gauge wire from Belden with at minimum 150 degrees C heavy polythermaleze insulation ( try PlanetEngineeres for single 1 pound spools of wire in many different insulations and gauges ) with an occasional 35 gauge, 39 gauge double winds, 39/40 gauge double winds, and 40 gauge double winds done for experimentation. My standard arm was a 10 feet of 36 gauge wire on a 2 lamination blank with a old T-Jet comm; would adjust from there if the track had long straights or needed more “punch”.
> 
> When winding an arm lay the first layer down nice and straight and packed tightly so that the next layer will not push through; do not extend the first layer into the curved area of the winding surface near the tip. Use only fingers and soft tools to move the wire into position or to tamp the wire down, the use of metal anything can lead to the scratching of the insulation on the wire and to arm failure. The second layer, and if possible, all further layers of wire should naturally fall into the “valley” created by the two wires below it. The “idea” is to produce the “ideal” arm with flat straight layers of windings. I’ve managed a few, they are very good and last a long time.
> 
> A word on balancing. Once you have a workable technique for rewinding down the need for balancing becomes somewhat less important. Being able to repeat the technique for the three poles introduces minimal variation in mass. Thus the choice for balancing becomes the removal of mass not the addition of mass. The amount of magnetizable material removed is minor when compared to the magnet field produced by the pole energizing.
> 
> However the amount of mass one may add in balancing through epoxy can have on the overall performance of the armature could be significant. Increase in heat and a longer time to reach maximum RPMs are first to come to mind. Regardless of what balancing you did initially, after the first few runs or first race it’s time to rebalance because all those little wires have moved around a bit ( it’s good to epoxy coat the windings ).
> 
> My 2 cents worth.
> 
> Keith VanAtta


Thanks for the great advice Keith. Now I have some questions. By my calculations 10 feet of 36 would give a final ohm value of 3.04 ohms. Is this suitable for a fairly tight home track with 19.6 volts and 4.5 amps? Most of the Aurora arms that get lower in ohms seem to lose torque and gain top end, is this due to the apparently smaller gauge wire Aurora used? Would a lower ohm arm comprised of a thicker gauge make up for this lost torque and add top end punch also?

Dyno


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## K.L. VanAtta

Dyno,

There are a lot of factors that go into making a fast car on any given track. Armature/motor wise for what you’re describing I would try a single 37 of about 12 feet, magnet to arm air gap of 10 to 15 thousandths of an inch with Super II, JL, or Dash magnets. If you’re just playing at home and have no worries about rules, then a 0.008 K & S tin shim behind each magnet will help in terms of the magnetic field to the arm.

In general try for 4.5 to 5.0 ohms for a drive-able car. Remember that a smaller magnet to armature air gap will give better brakes and acceleration but will run hotter. A larger air gap will give better top end but slower acceleration. It is a game of compromise to match the car to your driving style to the track to all the lanes.

Adjust from there with gears. In the 70’s we were limited to the stock 15 tooth, the Tyco 18 and 19 tooth crowns, and the Super II 19 tooth crown. Now it looks as if you can use anything from 20 to 24 as long as it doesn’t hit the rails. Of course the former options are still available.

Keith VanAtta


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## Dyno

Keith, thanks again for the advice. :thumbsup: 

My track only has 7 foot straights and some tight turns, including a hairpin. However Im in the process of helping a friend build a fairly large 4 lane at his house with 15 foot straights. I dont have any 37 gauge wire. I have a spool of 36 now, and a spool of 38 coming on monday. How does 10 feet of 38 sound. It should be about 4.8 ohms I believe. One more question. Whats the advantage of a double or triple wind? 

Thanks, Dyno

pic of my layout


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## K.L. VanAtta

Dyno,

Without going into a bunch of DC Electric Motor Theory, which has been covered very well here on HobbyTalk by several members/HO racers ( excellent job! ), the 38 gauge can not transmit the same maximum amount of current ( expressed in amps ) as 37 gauge or lower numerical wire sizes. This then affects the ability of the armature pole to produce a magnet field which then propels it to the magnet. The larger the wire ( smaller numerical wire gauge ) the greater the amount of current it can carry and the stronger of a magnetic field it can produce which equals a faster spinning, higher torque motor.

Of course this is slot car racing and sometimes the general rules of physics appear not to apply, but, that is only because there are so many variables that must be accounted for.

The one big drawback of the pancake motor design is the gear train. Inline cars have two gears compared to five in the pancake motor car. Consider this when comparing the power of the two types of motors; think of the massive amount of energy those five gears consume!

In principle two wires of a smaller gauge will carry slightly more current than a single wire that is three gauges larger. A 40 gauge double wind will be equivalent to a single 37 gauge wind of the same winding dimensions.

Keith VanAtta


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## tjetsgrig

These are a couple of my Custom Quads........keep at it Dyno!!


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## Joe65SkylarkGS

tjetsgrig said:


> These are a couple of my Custom Quads........keep at it Dyno!!


Those are flying just sitting there bud!!!:woohoo:


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## Dyno

K.L. VanAtta said:


> Dyno,
> 
> Without going into a bunch of DC Electric Motor Theory, which has been covered very well here on HobbyTalk by several members/HO racers ( excellent job! ), the 38 gauge can not transmit the same maximum amount of current ( expressed in amps ) as 37 gauge or lower numerical wire sizes. This then affects the ability of the armature pole to produce a magnet field which then propels it to the magnet. The larger the wire ( smaller numerical wire gauge ) the greater the amount of current it can carry and the stronger of a magnetic field it can produce which equals a faster spinning, higher torque motor.
> 
> Of course this is slot car racing and sometimes the general rules of physics appear not to apply, but, that is only because there are so many variables that must be accounted for.
> 
> The one big drawback of the pancake motor design is the gear train. Inline cars have two gears compared to five in the pancake motor car. Consider this when comparing the power of the two types of motors; think of the massive amount of energy those five gears consume!
> 
> In principle two wires of a smaller gauge will carry slightly more current than a single wire that is three gauges larger. A 40 gauge double wind will be equivalent to a single 37 gauge wind of the same winding dimensions.
> 
> Keith VanAtta


Keith, 

Thats the best explanation I have heard regarding wire gauges vs power. It makes perfect sense the way you explained it, Thank you. I have a 2 lam blank and a comm plate sitting on the table waiting for my new wire to get here. Im on my way to The Home Depot to pick up a clamp-on Vice to hold the winder. Stay tuned for round 2 of rookie armature winding attempts coming soon... 

Dyno


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## Dyno

tjetsgrig said:


> These are a couple of my Custom Quads........keep at it Dyno!!


SICK! You can bet I will keep at it.


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## hrnts69

Great Thread Guys!

Iam wondering if its possiable to wind too hot of a motor for a givin size wire. Like a 0.75ohm motor would be 34awg wire at 4 ft long. Is that too much power for that size arm?

Or 34awg wire at 2ft ends up 0.37ohms. Is that even possiable to do? Will the wire handle that much? Or would a bigger wire be mandatory?

Blake


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## tjetsgrig

Blake,
I go with multible strands of smaller wire to achieve lower ohms ( see Keith's post ). If you want a .75 ohm motor, I wouldn't be road racin' it! Single strand low ohm motors won't last as long.


Jim Sgrig


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## Joe65SkylarkGS

tjetsgrig said:


> Blake,
> I go with multible strands of smaller wire to achieve lower ohms ( see Keith's post ). If you want a .75 ohm motor, I wouldn't be road racin' it! Single strand low ohm motors won't last as long.
> 
> 
> Jim Sgrig



How many you torch up??:dude:


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## tjetsgrig

Joe65SkylarkGS said:


> How many you torch up??:dude:


I havn't let the smoke outta one for quite some time.......the comms will wear out rendering it useless. On the other hand, if a gear lets go.....the wires will break and it's toast!! Listen to this baby wind up and check out the smoke!! That's a 2 laminate.....


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## hrnts69

So for low ohm arms, do a double wind arm. But how do you do that? Is it 2 seperate peices of wire per pole?

How many passes can you get out of a singe wire 1ohm 2 Lam motor? Would 5 passes be asking too much?

My plans is just to build drag arms. Iam really interested in building a couple Outlaw Tjets.


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## joegri

after reading this thread i go to the cave and take my custom wound tjetsgrigs powered roadrace arm jet for a few hot laps. very rewarding.this has turned out to be my favorite thread these last few days.


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## Joe65SkylarkGS

tjetsgrig said:


> I havn't let the smoke outta one for quite some time.......the comms will wear out rendering it useless. On the other hand, if a gear lets go.....the wires will break and it's toast!! Listen to this baby wind up and check out the smoke!! That's a 2 laminate.....
> 
> YouTube - Outlaw Tjet Breaks A Gear During Launch



Ouch!!!!lol


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## Boosted-Z71

Just got my arm from Tjetsgrig, all I can say is wow, its almost to neat looking to run.

Kinda busy for the next couple days, but hope to have the chassis done, maybe by the end of the weekend to try it out

He does excellent work.

Boosted


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## joegri

hey boosted hurry hurry i wanna see yer chassis with the yellow jacket!!! yer gonna dig every lap ya take. good things come to those that wait.


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## tjetsgrig

Thanks for the kind words guys! I take my time and try to provide a quality product. If it ain't good enough for me........it ain't good enough for you!!!! :thumbsup:

Thanks again!!


Jim Sgrig


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## tjetsgrig

hrnts69 said:


> So for low ohm arms, do a double wind arm. But how do you do that? Is it 2 seperate peices of wire per pole?
> 
> How many passes can you get out of a singe wire 1ohm 2 Lam motor? Would 5 passes be asking too much?
> 
> My plans is just to build drag arms. Iam really interested in building a couple Outlaw Tjets.


Yes, two separate strands of wire. At 1ohm, you will get way more than 5 passes. Don't free rev a low ohm motor!!! It will reduce it's life span. If you are building an outlaw, start at 1ohm and work your way down from there, you'll find out quickly what likes to break. You'll also need a nice stiff wheelie bar. Try not to crash.......or, you'll have a pile of parts!!


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## Boosted-Z71

Started on the chassis for the Tjetsgrig arm today,Cleaned, polished brass, Boiled it, checked the flatness & straightness of all the shaft holes, got the gage pin rear axle & gear train together, shimmed & installed. The chassis is in the lapping tank now. I will get it cleaned up & some pics soon. My goal was to have it broke in, tweaked and ready to race by next weekend. Just have to see how everything else goes. I am giving this baby every chance to be my #1 bullet.

Boosted


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## tjetsgrig

Let us know how it goes Jeff! Sounds like you're doin' it right.

Where's Dyno? I'm curious.........


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## joegri

i,m guessin that the dyno wrapped a monster up and he cant put the controller down! busy burnin up the trak!!


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## Boosted-Z71

Here is a couple of pics as promised, just starting to break in the arm now on low power.

I do have a question on a "Fray" car build technique. I have seen several chassis that the brush springs have a slight blue tint to them as though they were heated & possibly tempered. Anyone have an insight on the process to do this correctly, I assume it is done to get more spring tension for the brushes or to keep them from relaxing under heat? 

Don't look too close at the body, I am going to fit it to this chassis but I hope to pick up something that looks better in the future. My problem is there is nothing around here, as far as Hobby shops that carry any HO stuff, so I pretty much have to find what I want on the internet, order & ship.

I almost have my 1st attempt @ a 17 ohm arm wound, I cant wait to see how Jim's arm runs & then compare my wind to his. I actually rewound one pole after I saw his arm, They truly are works of art. :thumbsup: 

Boosted


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## Brixmix

Ok Boosted my first question is what kind of car are you trying to build? A Fray rules car, a Drag car, or just something to run at home with no rules?

As fare as the brush springs go on a Fray style car you don't need much brush tension (more = dynamic brake) if you are using Wizzard Brushes all you need is about 3/4 of the brush sticking through the chassis brush hole. In most case's a High ohm road race car you want the car as free as possible. You also want to make sure the chassis and plate holes are as tight as you can get them and still have everything move VERY freely ( NO Wobble) this helps make the car quiet and lets the gears last longer because they don't chatter. when putting the top plate gears on make sure they are on flat (RTHO gear press works best) you want to have minimal up and down movement so press the pinion on so it has .002" to .003" clearance up and down movement same with the arm because if the arm has too much up and down movement your brushes can push arm up and down and make the car feel inconsistent.


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## Boosted-Z71

We run "Fray" rules cars, but about the only checking that goes on is to ohm the arm, 16 ohm avg, checked at room temp, along with checking the magnets, People run Dash, JL & we even have a guy that runs Super II mags, otherwise the cars closely resemble "Fray" built cars. So yes we have rules but we dont get overly involved in tech inspection unless it's something quite obvious, bearings, weight or the lack of etc. I agree on the gear train, I have a lapping process that works well & the cars roll very free afterwards. I had just seen a couple of the cars with the blue looking springs & wandered if they were somehow tempered for stiffness.

Tjetsgrig's arm likes a little more brush tension than I normally run, It really came to life after the brush tweak, I Still need time to tweak the shoes & some more run in time, only had it on 14-16 volts as well, that little bomb is going to fly on 20 volts


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## Dyno

tjetsgrig said:


> Where's Dyno? I'm curious.........



Im still here, I unfortunately havent had time to try winding a second one up yet. I have a new spool of 38, a bare arm, and a prepped comm, just not the amount of time I need to give it another try yet.  Maybe tomorrow.


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## Brixmix

I guess I was curious as to the rules because I know Fray, ECHORR, Quarrel do not allow rewind arms no matter what the ohms are, but it really doesn't matter if it's local club racing where its just home rules. If there is any questions you have in car prep I might be able to help alittle


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## joegri

hey boosted i,m diggin the gearplate venting. and what is that final drive(white gear) do tell. that looks to be some type of "outlaw" racin chassis. nice man . !!! and dyno no pressure man take yer time i just like to watch.


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## Boosted-Z71

The vented gear plate is just a build tool used to check the air gap between the magnets & the arm, as for the white gear it is std size, it is a nylon gear that I bought several a while back, they lap very well & you wind up with a very smooth & long lasting gear train afterwards. I have a really "modified" brass pan T-jet chassis (think flex master) that I have been working on for a while, its going to get the first double wind arm that I get done. Its got all the normal setup work into it plus some machining for Super II brush cups & to lighten & ventilate it as well.

I will try to get some pics of it up soon. 

Boosted


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## hrnts69

Hey guys, i just did my 1st arm this weekend. 3ft of 38, which got me 1.1ohms. But i belive i made a mistake. I was looking at my stock arms and noticed that where the wires are tied to the comm plate, i reversed them.

So does this mean that the motor will run backwards? Thus only be used in 4 gear cars?


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## alpink

if the motor runs backwards, reverse the magnets.


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## tjetsgrig

hrnts69 said:


> Hey guys, i just did my 1st arm this weekend. 3ft of 38, which got me 1.1ohms. But i belive i made a mistake. I was looking at my stock arms and noticed that where the wires are tied to the comm plate, i reversed them.
> 
> So does this mean that the motor will run backwards? Thus only be used in 4 gear cars?


Yes, if you secured them to the wrong lugs, the motor will run the opposite direction.....


JS


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## Bill Hall

hrnts69 said:


> Hey guys, i just did my 1st arm this weekend. 3ft of 38, which got me 1.1ohms. But i belive i made a mistake. I was looking at my stock arms and noticed that where the wires are tied to the comm plate, i reversed them.
> 
> So does this mean that the motor will run backwards? Thus only be used in 4 gear cars?


The four gear just reversed the magnet position...if memory serves.

No reason you cant do the same.

Right?


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## tjetsgrig

Bill Hall said:


> The four gear just reversed the magnet position...if memory serves.
> 
> No reason you cant do the same.
> 
> Right?


Correct Bill. Just gotta remember which car has the reversed mags!


Hey.......where's Dyno?? I'm still curious.........


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## Boosted-Z71

I would be winding as well, but I am too busy racin, showing the rear bumper of that new little rocket to the local crew. I have already heard several comments that their getting tired of seeing it. HA ha. Nothing like a new bullet in the stable.

Their all waiting on it to slow down or burn up, it gets faster every time out & is now running as cool as ice.

Boosted


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## tjetsgrig

Boosted-Z71 said:


> I would be winding as well, but I am too busy racin, showing the rear bumper of that new little rocket to the local crew. I have already heard several comments that their getting tired of seeing it. HA ha. Nothing like a new bullet in the stable.
> 
> Their all waiting on it to slow down or burn up, it gets faster every time out & is now running as cool as ice.
> 
> Boosted


Awsome Jeff!! Glad to hear it........keep kickin' it out man!!

JS


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## joegri

hey boosted glad to hear it. told ya so. tell,em to get used to it!!!!


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## Boosted-Z71

Yep, I know who to call Tjetsgrig knows just a bit about armatures

Thanks, its a really fun car, wish you guys could hot lap it as well.

Boosted


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## fastesthoguy

Boosted,

Sent you a PM regarding your local racing.


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## Boosted-Z71

PM'd you back

Boosted


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## Dyno

tjetsgrig said:


> Hey.......where's Dyno?? I'm still curious.........


Im still dying for a chance to get to my second try but Ive been really busy with work, and shoveling snow, lol, also Ive been at a friends house helping him build a slot car motorsports complex. He is in the middle of wiring up a 
16x4 four lane, and building a shelf for a drag strip, he also has another 16x3 table for an oval or whatever he has in his minds eye. I wish I had that much room to work with.

As soon as I get to it, success or failure, it will be posted here.


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## K.L. VanAtta

Good Afternoon Everyone,

I finally got a bit of time to play with slot cars again and decided to do a refresher experiment on the magnetic field strength that is produced when a pole of an armature is energized. As you know, the armature pole is energized with an electrical current running through ( technically, on the surface of ) the wire wrapped around a material that is magnetizable, creating a magnetic field that is opposite to that of the permanent magnet the armature is rotating towards. These two opposite magnetic fields attract causing the armature to accelerate until it reaches it’s maximum rpm.

What I wanted to do was to measure the strength of the magnetic field produced by various types; inline and pancake, and different winds; stock, Super II, and rewind. Following is the setup:

WrightWay 1/24th Power Supply, 0v to 11.75v DC, 0 to 10 amps

WrightWay ( Acello ) Gauss Meter, -1999g to 1999g, 

All arms tested at 0.99 vDC. Reading in gauss for one pole.

All Electronics $0.50 slot car motor: 30 gauss ( This is a Mabuchi HT-50 type Can Motor )

Tomy Super G+ Armature: 62 gauss

Auto World T-Jet 500 Armature: 52 gauss

Aurora Blue Tip Drag Armature: 91 gauss

Aurora Super II Armature: 128 gauss

Own Rewind, 9.5 feet of 36 on a 2 lam Armature: 141 gauss

Some information for those of you who are thinking about rewinds. I know that the question was asked about the difference between the same ohm armatures but having different wire sizes. It’s all about which can carry the most current the most efficiently; the larger the wire the greater the current capacity the more work it can do. Maybe not in the way you want it to, but, that is where all the other factors of slot car racing come into play.

I needed to do this experiment to help me design a 12 ohm can motor for BRASCAR and scratchbuilding applications without needing to turn down the volts. Hopefully, in a few weeks I’ll have something to share.

Here’s a photo of some arms done back in the 70’s, the two on the right by me, the two on the left by Merril Rowe.









Be Good,

Keith VanAtta


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## joegri

mr. vanatta i,m not an arm winder but i have seen some of yer stuff on the scratch building site. those arm look like candy and do appreciate the stuff you post. dont be a stranger. you do influence many wana be scratch builders .the above post is very interesting and i,m following this thread closely.maybe show more of yer stuff?


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## sidejobjon

hrnts69 said:


> Hey guys, i just did my 1st arm this weekend. 3ft of 38, which got me 1.1ohms. But i belive i made a mistake. I was looking at my stock arms and noticed that where the wires are tied to the comm plate, i reversed them.
> 
> So does this mean that the motor will run backwards? Thus only be used in 4 gear cars?


Wow 3 ft i thought was like 9 ft each pole? Is that all
Thanks SJJ


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## jimc1951

*armature question*

I just rewound 2 arms for my home track w/ wall warts(Tomy)1 of the arms is wound w/7ft.7in. of 39 ga.= about 4 1/2 ohms. The other arm is wound w/ 38 ga. about 11 ft. per pole=about 5 ohms.I'd think that the 38 ga. would be faster due to larger wire. The 38 ga. loses badly in to a super G+ ina 7 ft. straight from standing start.(same gearing) The 39 ga. gives the G+ a real run for it's money. The stock super G= has 172 turns of 38ga. vs. the 120 turns I used. I'm kinda new to this but am i missing something here? Larger wire=more volts=faster? Shouldn't lower ohm car be faster?I could use a few pointers here as i haven't even attempted this stuff since around 65-66!Also,timingtires &gearing are all the same.Thanks----jim


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## ruralradio

*More Power!!*

Your wall warts probably don't have enough amperage for the 38. The 39 is happier with less power. If you have a long track without extra power taps, you may also notice the rewinds aren't as responsive on the far side of the track.


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## jimc1951

*rewinding*

If it's due to low power on wall warts then how do the super G+ cars run so well? They also have 38 ga. wire but use 172 turns (13 ft.) vs. my 38 ga. rewind w/120 turns(about 11ft.)by taking 2 ft. off the windings does it cause car to use that much more power?I'm trying to learn as much as i can . Thanks---Jim


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