Let's talk stock motors

[Nairb]

OK, I'm gonna try to supe up my Chrome stock a bit. I think you told me to try the Trinity P2K springs (green & red). I'll go buy some extras, but I was thinking about trying my Midnight springs. They're identical, both black, and close to 180 degrees. So they're a lot stiffer than the stock springs (they look close to 90 degrees). What do you think about these? They should give me great torque, but will RPMs suffer too much?

I took off the stock brushes (I hear they are crappy), and I'm gonna put on some Warlock 680s (they seem identical to Reedy 767s, I'm convinced they are the same).

What are your suggestions (anyone)? BTW, I'll be using it in my XXXT on a tight indoor track.

Also, any suggestions for tweaking my P2K? Right now I've got stock springs and Reedy 767s installed.

[ 05-08-2001: Message edited by: Nairb, the opinion-filled piñata ]

[Grizzbob]

Wow, a thread just for me.... :D
Anyway, to answer your questions, the polarized Trinity spring set up might work on a Chrome, but I haven't tried it on one so I'm not sure(I know it works on a GM3, but I don't know if torquier motors will benefit much). For motors that specialize in torque, I've liked running them with fairly firm springs(some of them really work with purples all around, but not all of them). As for 767's, I still like them better than any other stock brush, though I haven't tried all of them yet(we just can't seem to get Putnams here, & while I definitely like Niftech's, they're not easy to get here either). Now, if you want a little more rpm with the 767's, then you might try 768's, they're the same compound, but with a vertical slot cut in them, or 769's, (they're also the same, but with a cavity). However, for raw power, nothing seems to beat a full-face brush, so for starters I'd suggest something like 767's with purple springs, & see if you can have it tested on a dyno(or failing that, try hooking it up to a 4 cell pack or 5 volts off a Turbo35, & listen to the pitch of the motor, higher tone, higher top end. Also, try to keep in mind how fast it hits top end, that's an indication of how much torque its putting out). If it doesn't top out too good, then try going one step softer on the negative spring, & try again, & then one step softer on +, etc. It may not be the most precise way to do it, but it's better than nothing. On the dyno, obviously you want bigger numbers in all categories, but power is a good thing to concentrate on(particularly how fast it reaches max. power). Also, keep in mind, that when you're cutting the comm down for each new pair of brushes(I'm assuming you're doing that), once you cut it down so far, then the motor will only get slower(I think it just gets to the point where there's not enough copper left on the comm to make good power, most of us agree that when the comm diameter is less than .270", it's done), so it's a good idea to measure the comm diameter every time you cut it, & note when the motor starts to lose performance instead of gaining it..... :cool:

[SirSpeedy]

Hey guys,

My good friend Scott Haake won the 2000 ROAR National Championship in Stock Sedan last year.

He bought two handouts. You know what Mike Reedy did to them? Skimmed the comm, put in 767's, put Sonic springs on 'em, bent the positive on a little to make it a little firmer. That is it.

Stock racing order of importance:

1. Driving
2. Batteries
3. Setup
4. Tires
5. Motor

Time in front of a dyno is better spent on the track.

[Kevin_366]

i would like to learn more about the motors.... what are comms and what do the springfs do? if there is a link about this could you please tell me... thx

kevin

[Grizzbob]

Of course, you're right Speedy, but all things being equal, that time at the dyno DOES make a difference. I assume that someone getting this deep into it has already developed their driving skills, gotten good batteries, set up their car properly, & put on the proper tires. Kevin, to answer your question, the comm is short for the motor's commutator. It's part of the armature that the brushes touch to complete the electrical connection, & the springs are the, well, springs that push the brushes into contact with the comm(I'm not really sure how to describe springs any other way). I'm sorry I don't know of any links to pics of these things, maybe if you explore this or Trinity's website you may find some good pics that may help you.... :)

[Nairb]

Nah, trinity's site ***** for info (except TT) & pictures. You can probably find plenty about motors here: http://rcvehicles.about.com/hobbies/rcvehicles/mbody.htm ...or some other site.

"He bought two handouts." <-- That sounds kinda weird, BTW.

I know all I need to keep my motors running well are true comms and the right brush/spring combo (besides gearing correctly). I'm happy with Reedy 767s, but I want to find the right springs for my motors. Like you said, Mike Reedy changed his springs.

Tim, I got 2nd place in stock on Saturday, so I think I have most things under control in that list of yours. Why not try to improve something in the top 5?

[SirSpeedy]

When you go to a National Event, you get one handout with your entry, with the option to buy more. Scottie bought an extra.

The Rage handouts for the Nat's last year did not have brushes or springs installed. If you buy a The Rage Type R, it comes with 767's and the Sonic 2 springs, with one bent a little. It is well documented that a heavier spring on the postive side of any motor is better for many reasons. Every stock motor on Earth comes with light/heavy springs now on the 'tuner' versions.

All Mike Reedy did was take a Rage that was fresh of the boat from Japan, and make it a Type R, just like you buy off the shelf at the LHS.

MY POINT:

Keep it simple. No brush tricks. No comm sizing to the "sweet spot". Just drive it.

[Josh00]

Just reading this collum i learned about a bunch of stuff i didnt even know there was about motors(im new to the r/c thing)... How can i adjust the springs and brushes on my motor to make it well...better heh please reply

[Railman]

Sir speedy, How do you think Mike that got to where he could just throw a set of brushes & springs on a motor to maximize it?
He spent many years on the dyno to learn what he knows. Once you know what to do, it's easy, just like anything else. You've got to get there 1st though. We do this stuff for a lot of different reasons. We all want to drive well, but some like the technical side, & actually enjoy it more than the driving. I know an older guy that bought a Robotronics just because he likes to "fiddle" with motors. He's not super fast
he just enjoys the technical side. Whats wrong with that?

Grizz & Piniata, I have my own theories on motor brushes & how they should be cut for different applications. Like grizz said, for maximum brute power (trucks), full face is better. The only thing I would add however is that if you have long staights, or run buggy, you may need to tune towards that with a reduced surface...
drill holes, slot, H cut, or what I like best is serrated with a small V cut on the sides instead of a full slot. I think the leading edge carries the brunt of the amp draw as it is the 1st part of the brush & com to fire the arm coils. My thinking is that the center of the brush wears slower than the part that needs the pressure the most. If you reduce the surface at the center of the brush the leading edge will keep better contact, & conduct better there. It also helps to even out the wear a little, & of course reduce friction. I have yet to hear of this concept from anyone however, other than in my twisted mind. Buggys need less punch than trucks & I think work much better with a reduced surface brush. I think I need to stop this one now, getting toooo long, talk more later. ;)

[SirSpeedy]

You proved my point in the first two lines of your post. Thanks.

Mike has it figured out. The 'tuned' versions are at their absolute best for nearly every class. 1/12 scale being the exception.

But hey, if you are into the "technical side" Go for it.

[Railman]

I also buy the tuned versions of all the motors we buy for the same reasons. You can tune for different vehicles, tracks, jumps, & driving styles however. Agreed?