STOCK motor forum
#856
Tech Apprentice
Originally posted by Pit-racer
What car was it ran in?
What car was it ran in?
#857
Blakesrc
I'd skip the hood alignment tool. You really don't need it. Install a new set of brushes and align the hoods for that set of brushes. Since different brushes are slightly different shapes, you should always check to make sure they are aligned if you change brush brand or model. The way I align my hoods is to install the new brushes and run them in on my T35 for 20 sec @ 2V. When you take the brush out and look at it, you should see either a shiny area somewhere on the face of the brush or the edges of the face, on both sides, will be shiny. If the edges are shiny and the middle is not, you need to wear the bushes in some more before you can align the hoods. Usually, you will see the shiny spot on the face and it probably isn't right in the middle of the face of the brush. You need to cock the hood so the shiny spot is in the middle. After you make a change, run the motor for 10 or 15 seconds and check the brush. It helps if you have a comm stick to scuff the face of the brush, since it becomes dull and makes it easier to see the shiny part. The reason you only run it for a short time is that's all it takes to get a shiny spot you can easily see and you aren't changing the shape of the brush face with such short runs. Once you experiment with it a bit, you'll figure out which way you have to cock the hood to change where the shiny spot is. If you use any Yokomo based motor (Reedy MVP or derivatives,) you'll need to remove the hood completely and enlongate the hole slightly or you'll never get them aligned. Use an x-acto knife and scrape away a little material on the inside edge of the post hole only. Usually 10 or 15 good scrapes is enough. You don't need to worry about it on EPIC based motors (like the P2K, GM3, P2K2, etc.) One final thing. Make sure you align the hoods by running the motor in the same direction that it will be running in the car! If you install the motor and the car goes backwards, you'll need to realign the hoods in addition to switching polarity on the motor. Good luck!
I'd skip the hood alignment tool. You really don't need it. Install a new set of brushes and align the hoods for that set of brushes. Since different brushes are slightly different shapes, you should always check to make sure they are aligned if you change brush brand or model. The way I align my hoods is to install the new brushes and run them in on my T35 for 20 sec @ 2V. When you take the brush out and look at it, you should see either a shiny area somewhere on the face of the brush or the edges of the face, on both sides, will be shiny. If the edges are shiny and the middle is not, you need to wear the bushes in some more before you can align the hoods. Usually, you will see the shiny spot on the face and it probably isn't right in the middle of the face of the brush. You need to cock the hood so the shiny spot is in the middle. After you make a change, run the motor for 10 or 15 seconds and check the brush. It helps if you have a comm stick to scuff the face of the brush, since it becomes dull and makes it easier to see the shiny part. The reason you only run it for a short time is that's all it takes to get a shiny spot you can easily see and you aren't changing the shape of the brush face with such short runs. Once you experiment with it a bit, you'll figure out which way you have to cock the hood to change where the shiny spot is. If you use any Yokomo based motor (Reedy MVP or derivatives,) you'll need to remove the hood completely and enlongate the hole slightly or you'll never get them aligned. Use an x-acto knife and scrape away a little material on the inside edge of the post hole only. Usually 10 or 15 good scrapes is enough. You don't need to worry about it on EPIC based motors (like the P2K, GM3, P2K2, etc.) One final thing. Make sure you align the hoods by running the motor in the same direction that it will be running in the car! If you install the motor and the car goes backwards, you'll need to realign the hoods in addition to switching polarity on the motor. Good luck!
#858
which set of brushes do you guys think is better - trinity silver brushes or reedy quasar? which will produce more power in a stock motor? thanks for any info
#859
Tech Master
iTrader: (5)
some motors like 767's more others like 4499's more. Axiom 12%'s usually work good, I haven't tried the new Trinity brushes yet but I'm sure they work good. If you just buy 767's and 4499's though, you'll be pretty good. Just try each one in the same motor and see which works better.
#860
Tech Initiate
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Last edited by Cube; 12-23-2008 at 10:10 PM.
#861
4499 vs 4391
Which brush is better for racing, 4499 or 4391 (polarized)? I have a p2k2-based Fantom motor.
#862
marvi: the quasar is the 729 which is a standup brush. Laydown version is the 766 which is a torque brush. 767 is the rpm brush, not as hard on the comm as the 4499's. I think JeffC said it the best in that some like 1 over the other. I have a DR2, promatch P2K2 that likes the 767's better than the 4499's.
#863
Re: 4499 vs 4391
purplepro3
Try 4499's with purple positive/red negative.
Try 4499's with purple positive/red negative.
#865
Tech Regular
iTrader: (4)
Aluma, Check that the comutator does not have filings left in the gaps between the segments from cutting the comm. Take a xacto or similar sharp object and run it through the gap to clear it out. If there is any filings in there it could cause it to short out and lose power.
#866
Tech Elite
Having same problem
This is the EXACT same problem that I'm having with my HPI Pro-3 and P2K2 "pro"
If I gear down (lower final) then the car has no punch in the corners. The car feels best with a 7.2 to 7.4 final ratio but then the speed suffers on a long straight.
The Motor looks perfect upon inspection. I know how to true the com, shim the arm, brushes #767's with cavity, springs Red/Green.
The belts on the car are as loose as can be without skipping, and I've Degreased the Bearings already.
I was thinking of going to 1 deg toe in back to increase the speed.
The car is really planted in the corners.
Thanks,
If I gear down (lower final) then the car has no punch in the corners. The car feels best with a 7.2 to 7.4 final ratio but then the speed suffers on a long straight.
The Motor looks perfect upon inspection. I know how to true the com, shim the arm, brushes #767's with cavity, springs Red/Green.
The belts on the car are as loose as can be without skipping, and I've Degreased the Bearings already.
I was thinking of going to 1 deg toe in back to increase the speed.
The car is really planted in the corners.
Thanks,
#867
Tech Regular
gear UP
#868
Tech Regular
Guys, When you are doing your rebuilds are you using new brushes or reusing the same set? If you are using new brushes they need to be broke in(fully seated). if you are re-using brushes (which is ok) you may need to gear slightly differently, when the serrations are completly worn off the brush the motor will produce less RPM and a little more torq, so you may need to gear up a little bit. Another thing that you need to keep an eye on is the size of the com. As it gets smaller the power band will change some, and when it gets really small you may need to narrow the brush a little bit to reduce the overlap between poles.
Chad
Chad
#869
Tech Elite
Not working
I tried to gear up and the car is a pig in the corners.
Right now a final ratio of 7.0 seems to be a good compromise between speed and punch. But the car is getting passed on the straights by 50% of the other cars.
What about the firmness of tire inserts having an impact on top speed. Using HPI 24mm Red inserts now.
If no one can give some better Ideas before this Thursday, I think that I will try less toe-in at the backend of the car.
Thanks,
Right now a final ratio of 7.0 seems to be a good compromise between speed and punch. But the car is getting passed on the straights by 50% of the other cars.
What about the firmness of tire inserts having an impact on top speed. Using HPI 24mm Red inserts now.
If no one can give some better Ideas before this Thursday, I think that I will try less toe-in at the backend of the car.
Thanks,
Last edited by popsracer; 11-18-2002 at 02:27 PM.
#870
Popsracer - HPI reds should be fine. You can try green if you like. Just a bit harder. However, the problem could be your motor. I know several people swear by the P2K2s but I've never liked them. I've run P2Ks in the low 6s and GM3s in the high 6s with great results. I've had 2 P2K2s and they both blew chunks. Anyway, If you're gonna try to get that motor to work, I've always been told 4499s (Trinity E-brushes) on Trinity motors. Also, you can add a little jump outta the corners by tightening up the diffs a hair. If your car is tracking well, is should not affect your handling.