Mike F

Hey Alvin - could be that your hoods are not align correctly. just a guess thogh. If you want to really know ask BigJim on the general discussion thread at Hobby Talk. Jim knows his stuff

Cole Trickle

Lately I gor my Spitfire comms trued and I mounted Reedy 767 brushes.

For my driving style and my Sport2 (heavy transmission) and a very tight track, I need torque. The Reedy 767 should give a little more torque, but it seems like my Spitfire has less torque now, than before.

How can that be?

PS: I'm not really happy with the Spitfire, too little torque anyway... I like the P2K much more...

Simon K

Alvin,
I cut my #766 brushes(as per Big Jim suggestions) and also run different springs on my MVPs.
If you can get hold of PEAK Viper springs, I use a 135 deg on pos and 115 on the neg. Trinity Red and Green springs are also popular.

Gearing can be very subjective as a lot depends on the layout of your track. I run on a fairly technical circuit and run 6.35 in my Yokomo SP.

I have enclosed a pic from BJ showing how the brushes should be cut.

Cole,
As the comm on your motor gets smaller through being skimmed, you will lose torque but gain RPM. If the comm needed a deep cut, there may be quite a difference in "before" and "after" performance. Try dropping a tooth on your spur or pinion.
Also if the comm cut was quite deep, your brushes may not be seated properly. Do you run the motor in and check this before racing?

mike_Webb

Simon-

I have a couple of Core Stock Motors... Do you suggest the 767 Cut Brush on that Motor? I have the complete Viper Set of springs. Also I have teh Peak 2221 Serrated brushes. Will those do well? I am looking for some more speed and torque.

Thanks

Mike Webb

Simon K

Mike,
BJ has suggested running the Core/Hellfire motors with a brush/spring setup close to the MVP due to the similarities.

I'd cut the brushes as per diagram above, use the 135 deg Viper on pos, 115 on neg. Apparently the new "Hot" brush combo is a #767 on the pos and #766 on the neg, so I'd do this too. Basically all the brushes and springs are different according to the polarity.

I'm waiting for the NZ importer to land another shipment of brushes then I'll try it myself.

Try these suggestions and see if they make a difference, remember to make sure the brush hoods are aligned and the brush face is completely broken in.
Good luck

I've used the Peak 2221 brushes, I couldn't get anything else at one point. They are as good as anything else I guess, don't have a dyno to check any figures though. I run a set in my "Club racing" motor.

mike_Webb

Simon.... I am having a hard time Adjusting the brush hoods. I run the motor and see where the Brush is wearing but most of the time I cannot really tell. Is there a easier method? Also when you do that do you move the Hood up and down to adjust it or do you rotate one side back and forth?

Thanks

Mike webb

Simon K

You need to move them(individually) very slightly sideways, using a "bar" and not one of those Parma/PSE things which aligns everything as "one"

Use an un-serrated brush, I think the Peak ones are a bit too dark(and serrated) to see clearly, if you can, use a #766(they are pale, smooth and shiny). Run it for 20-30 seconds then look for the wear on the brushface.
Center-good, Edges-bad.

Its a horrible job, I know. Just be careful when tightening everything up, very gentle!.

Cole Trickle

Yep, the comms took a deep cut. So this makes great sense. Thanks.

I did a motor run-in for approx. 2 * 3 minutes on 3 cells. Most of the serrated surface was gone, but not all. Is that good enough? By the way, the motor got warm, around 40-50 deg. during run in. Is that normal? How do I check if the brush is seated correctly?

Thanks.

Jimmyd

Alvin
I believe the motor was getting too much shorting between the brushes caused by the use of laydown brushes. Try narrowing the faces of the brush by 1mm on each side by sanding a chamfer on the edges.

Alvin

Hello all,
Thanks for the replies! May I know how I should go about "cutting" the brushes? What tools should I use?

Also, I run 23T Stock motors which are also use laid down brushes. Do you guys think the brush cutting trick mentioned will help? My 23T runs at similar gearings but is far cooler, but hey, any little bit helps

Thanks again.

~Alvin

maski

alvin,
i have the same problem with my new fantom p2k2. i'm running 78/26 on my yok sp. after 2 runs the comm has some bad wear of brush that is the brush on 1 side is like toasted and its burned parts stick to the comm. after few more runs i true it but when i begin to break-in again it doesn't turn the moment i pull the trigger halfway. then i touched the motor and its hot considering i only pulled the trigger about 5-8 seconds twice but at full throttle it spins ok! when i open the can, i found out that the magnets had loosen. and when i tried to stick it on the can it eventually broke. maybe because of constant banging with the armature, the problem must be on the magnets. when i changed can, things go smoothly except the armature don't give enough power, maybe i have fried it a bit!

tips on buying a stock motor (tuned untuned)
try to rotate the shaft of the armature without the brushes on the hood. it must have at least 3 revolution when spin with force. if not, the motor has defect like the unequal size of magnets or has loosen.

David Galdo

iTrader: (15)

Trinity motors have really pissed me off. I tossed two GM3's and a P2k in the trash. The three motors had wear marks where the armature made contact with the poorly installed magnets.

I can't wait till the new Co-balt is released. I am going to postpone buying another Trinity till then.

Cole Trickle

Just checked the brushes.... In the middle the serrated surfaced is gone, but not in the start and beginning. It have run 7 batteries so far.

Any comments?

David Galdo

iTrader: (15)

7 batteries through the motor and you only see a wear mark down the center? That is good news if you had only run the motor for a few seconds on the first pack but not 7 packs. The full face of the brush should be worn with no serrations.

Cole Trickle

I'll say 50-60% in the middle is without serration. Gradually towards the start and beginning there's more and more serration. On the edges, the serrations are worn, but I can easily feel them with a nail, and I can easily see them. However, we're talking 1/10 millimeter.

Unfortunately, I aint got a digi-cam...

About gearing, I'm as low as 23/93 (48 dp) -> final drive ratio is 8,48. That worked great earlier, quite good punch and the motor aint get hot, just comfortably warm.