# Magnatraction brush spring question



## Dyno (Jan 26, 2009)

Does anybody know at what temperature will Magnatraction brush springs start to collapse?


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## dlw (Aug 17, 1999)

Springs will collapse naturally under constant pressure, however a hotter running car will collapse them quicker. Normally, Afx cars run fairly cool and any heating problem usually means something on the car is drag/binding somewhere. An axle or wheel may be tight, too much pressure on the brushes towards the comm, or even a top plate with a too-tight gear clamp. You may have a bad brush or arm, too.

If they need it, you can give the springs a gentle stretching. This also goes for pickup shoe springs.


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## Dyno (Jan 26, 2009)

Thank you for the answer but I'm more looking towards an actual temperature they begin to fail. This car is not even close to stock, it has a custom wound 3.1 ohm 36 gauge armature with polymer motor magnets. It runs very well but it does get hot. I haven't had any spring trouble yet, but I'm just wondering how hot I can let it get before either the chassis melts or springs collapse. I stopped running it when it hit 180 degrees.


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## slotking (May 27, 2008)

i used to put 2 springs in each pocket. somethimes I would cut 1 down a little bit.

I never gunned my mags to see at what temp the die, but would guess about 170.

I think someone is making after market springs that may work better


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## rholmesr (Oct 8, 2010)

I've flattened some mag traction springs on my superstockers that have polymer magnets and green arms. I guess they get hot enough to lose all their strength and when you pull them out they look like a flat washer. 

And to me the car didn't seem like it got all that hot. Certainly wasn't smoking or anything.


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## slotking (May 27, 2008)

170 should not melt anything.

I have cut down other springs to fit as well.
I also ran poly mags & any arm

so the stock springs did not last that long. My cars always sit low for max magnet attraction


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## Bill Hall (Jan 6, 2007)

*Pre-combustion*



rholmesr said:


> I've flattened some mag traction springs on my superstockers that have polymer magnets and green arms. I guess they get hot enough to lose all their strength and when you pull them out they look like a flat washer.
> 
> And to me the car didn't seem like it got all that hot. Certainly wasn't smoking or anything.


So the answer is just a little bit before they catch fire...LOL....good to know! When the springs sag out it's like flicking your Bic.

Can you hear it pinging just before detonation?


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