Jon Williams

iTrader: (5)

Bill, did you give up on your rotary engines?

BBSpence

iTrader: (64)

Nah, still have the RX7....I gave up on another car.

You guys coming down for this race in August?

TeamButter

iTrader: (3)

Funny Eric. I guess thats what happens when the "Sponsor" keeps the best batteries and motors for himself.

Jon Williams

iTrader: (5)

Bill, is that goodbye TC4?

BBSpence

iTrader: (64)

I've been struggling ever since I switched from a TC3 to a TC4. I think it's a good design and all, but I've been struggling with setups and consistancy. I had to make a change and the power of the darkside was just too strong.

Ortiz

iTrader: (3)

Any word on the Carpet Chassis for the BD???

ATLAS COPCO

Hi Eric
monster stocks the com seems to be a bit on the small side now but boy dose she go why is this, and what diamiter could i go to without all the segments coming apart

StephenSobottka

iTrader: (8)

HAHA! TOASTIE! That guy is a riot man, lol

BigDogRacing

iTrader: (12)

Yea Toastie is my buddy. He's a great guy, great racer with a good attitude and like you said- funny as he11!

We sure would enjoy you guys coming down Stephen so give it a shot if you can, of and tell your Dad I said hi!!

Atlas Copco- the reason the motor feels better with a smaller comm is that you have reached that "sweet spot" on comm size. This is why tuners like EA will usually take handout motors at big races and cut them like 10 thou right off the bat- that way the comm will be approaching optimum size near the mains. AS far as minimum size EA can correct me but about .270 is where they start getting pretty thin. Also, even though the segments might not come apart, when the comm is too thin it starts to lose a little power. I believe it's because the thin segments can't dissipate the heat from arcing fast enough but I may be wrong. EA will know.

StephenSobottka

iTrader: (8)

We'd like to make it but Trackside has their Summer Sizzler carpet race up here on July 30th! Its our big summer race as well.

Korey Harbke

iTrader: (13)

I'm not Eric, but I can probably shead some light on this topic.

As the com gets smaller, the brushes develop more "wrap" around the com. This results in more RPM. At the same time, the motor becomes less efficient, and heats up more in a run.

Generally motors with a bigger comm can make the same amount of power, they just have a powerband that is more in the lower RPM ranges. You can still maintain the top end speed by gearing up a bit with a larger com. It will generally run a bit cooler and fade less with a larger com as well because there is mroe copper to disipate heat, and there is slightly less "wrap" around the com.

I won't run any standard size com any smaller than .270 inches. They start at .300 (I think) before they are cut for the first time. For the larger mid com motors like the Reedy quad mag 19T and the Reedy Kr, I wouldn't run them any lower than .310.

Some motors tend to have a sweet spot for the com dia, but it varies from motor to motor. It;s hard to tell just off hand what a specific motor will run good at. Hope this helps a bit.

-Korey

ATLAS COPCO

Thanks for that Sushi boy

Korey Harbke

iTrader: (13)

No problem dood

-Korey

ATLAS COPCO

Sushi boy what if i shaved of a sma ll pice of the brush on the leading edge with a small com?

EAMotorsports

iTrader: (79)

Yea the last few cases I have gotten from Trinity are around .293 before I true them...They used to be around .295-.298 So after I true them now most are .290-.288 They do run better the smaller they get but I would rather leave the comm big when selling them new. But with them coming this small to begin with I just true them enough to be round.

EA