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Discussion Starter · #1 ·
The Mabuchi motors used in these toys cars leaves quite a bit to be desired. However, since they are intended for toys I won't gripe too much
My Scalextrics white GT40 motor didn't keep its power for long so I tore it down and saw the brushes in the end bell were toast. I swapped in another variety of Mabuchi end bell and it failed lickety split. OK, I might have swapped in more powerful magnets and a bit hotter arm as well so I don't mind its failing so quickly since it really didn't do so well in stock form.

My question is, what are you doing about brushes in these little motors?

I can't be the only one that is pushing these little cars harder than the factory intended. Yes, I could swap in a different motor but I don't like to admit defeat that quickly. I want to make the stock stuff work. I don't have many parts since I'm a newbie to 1/32nd scale cars so I can't cobble together too much stuff, yet. However, I have torn down enough of this style motor to have some stronger motor magnets and a few different armatures. I know that ohms isn't perfect for telling you what an arm is capable of but I still use it as a guideline. I found the stock Scalextric arm in the GT40 was 5.4 ohms. I put in a 0.5 ohm arm and it screamed. So I swapped in the 0.5 ohm arm and stronger motor magnets in the stock can. Now I need an end bell that will hold up.

Sooo, what I tried today is to take parts from my HO days and pervert the stock endbell. I took a set of Tyco 440 brush barrels, springs and brushes and drilled the plastic endbell to accept these parts. After tinning the ends of the brush barrels I pushed them in the endbell from the inside out until it hit the stop on the brush barrel then inserted the springs and brushes. Next up I quickly soldered short wires to the ends of the brush barrels that were tinned previously. Hooking up a 6v battery I found the motor spins up easily and seems content. I still haven't put this on the track as I don't have one at home so I don't know how it'll hold up under load.

Anyone else do this stuff? I haven't bothered rewinding the arms yet because of the brush problem. Nor have I changed stack length but I have changed the position of the stack in relation to the shaft in order to center the brushes better on the commutator with the fewest possible number of spacers.

I turned down a Mura endbell to try this but due to my not having any spare parts yet I found I didn't have a Wasp arm to put in the thing
I also figured it's probably overkill for these toy cars anyway so when I finally get the parts it won't be raced.

What are you doing about brushes on these things?
 

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Hi

I keep a stock of spares. When the power level drops, I toss it and put in fresh.

For .6 ohm arms, I use a proper modern endbell.

Or sometimes an antique for the 13uo.

Or sometimes a cut down SCX.

Fate
 

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Discussion Starter · #3 ·
I'm still building a stock of spares. What constitutes a 'proper modern endbell'? Is that like the one used in a 16d? Remember, all this is new to me, I'm from the HO world. Imagine my shock when I found out these big cars with huge motors were slower than molasses
I have Thunderjets that are faster
 

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Brian Ferguson
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Bill, I hear ya, I spent years in HO myself!


Yes, I believe Fate means 16D-style endbells, which is the way all motors for slot use should be built IMO.

To be honest.... my idea of spares now is just to have complete spare motors... if only they'd put proper endbells on these things! And they could.... they've even been doing it in HO for years!
Frankly, the current use of disposable motors is disappointing.
And before someone mentions cost... it would add very, very little to the cost of a car - I'd gladly pay the extra - and it would save plenty in the long run!
 

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IF you can turn down the Mura endbells per my article you can also use the Slot-It 26k-29k arms from their motors. They come with the better cummutators, to get a rebuildable motor and brushes. They are not that fast for the homeset cars and do a good job for me.

If I need a hotter arm for it I then rewind the Slot-It arms to what I want. You can also just put the Mura endbell on the Slot it can, so you don't have throw that away. That gives you a shorter over all motor that fits in places better than the Cheetah/Falcon can, which though, also can be shortend if you want to.

Here is a shot or two of the motor and parts.





 

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Discussion Starter · #7 ·
Fergy, I'd like better motors myself. It wouldn't add to the cost of these cars as they are already overpriced thanks to collectors. Of course, if it weren't for collectors these cars wouldn't look so good.

Larry LS, thank you very much. I didn't try using any of the armatures from my toy cars because I thought they all had the same lousy commutators. Those glued on copper tabs don't true very well as I'm sure you know all too well. I was starting to think I'd just have to get off my lazy butt and shorten the stack on one of the Revell SP500 arms I have then rewind it. I didn't want to go that route just yet as I have very few spare parts and these Revell arms are still perfect.

I changed the jig assembly slightly to suit my odd way of doing things but the article was the sole reason I even attempted to do the endbell mod. It pointed me in the right direction and that was something I needed, direction
Thank you for taking the time to post the pictures and the article.
 

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Two other cheap motors with good comms are the Cheetah II and the newer, new Fox motor. Make sure it is the new Fox with the longer cooling holes. Not the older shorter hole can or the one with no cooling holes in the can. As those two have the old bad comms.

I use these for re-winding also. They do need to be retimed though, as the timing on them is about 90 degrees off from say the Rabbit or Slot it motors. Not hard to do, just don't forget to do it.

Have Fun!!
 

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Hi

Silk purse out of sow's ear time..

If you really want to use those .6 ohm winds. Pull the motor apart. And carefully epoxy the leaves of the com, and then put a bit of thread around the front of the com and epoxy that, and then lightly epoxy the stack. Slow cure. Then true up the com.

Fate
 

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Discussion Starter · #10 ·
Silk purse out of sow's ear time..

Yeah, it's kind of overkill for these disposables but it's a weakness of mine


Great info guys, thank you very much.
 

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Brian Ferguson
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QUOTE Yeah, it's kind of overkill for these disposables

It's that exact "disposable" nature that irks me! It pervades every aspect of our society, but it REALLY bugs me that slot motors have followed suit. Yes, I know that we are at the mercy of the motor makers (Mabuchi, et al), but until I came back to 1/32 recently, every motor I've raced since the 60's was rebuildable. Progress? I think not!
 

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Discussion Starter · #12 ·
I've had three motors fail so far and every one of them had the same problem, the brush tension was almost nonexistant. Armature and the rest of the motor were still perfect. That's part of the reason I want to do something about the brushes. The other thing is I like fully adjustable brush assemblies. You can pick up some nice power fast by just using proper brush loading.

You can do some pretty trick stuff with the HO motors and all of them are fully rebuildable. I was a bit disappointed in the 1/32nd scale motors myself but that's what my friends are racing so that's what I race. Mine just won't be quite stock
One thing is for certain, these bigger cars sure do look good.

Another thing that's bothered me about these bigger cars is tires. Why are there 300 different tires? Why are they just silicone like I used on my Thunderjets for nostalgia races? It would be nice if I could buy various height silicone wrapped foam tires like those I used on HO cars. Those things hook great. Until then I'll be trying to make my own. I've already conceded that I'll have to make my own wheels so I may as well make tires too. I stink at this but I better get good if I want to keep up.

My plain jane white Scalextric GT40 already sports a 1/24th scale guide and lead wires as well as some other little things. I think of the car as Frankenstien, built from oodles of parts. The motor is made up from several other motors and I have a few other things I want to change in addition to the things I've already changed.

Fortunately where I currently play with my toy cars the rules are very loose.
 

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Hi

A friend who is a machinest and old school racer started casting sillies a couple years ago.

www.pumatires.com

It drives him crazy trying to keep up with the proliferation of RIMS the manufacturers seem to be making for no reason. I put silicones on the care immediately.

Fate
 
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