Restoring RC10 champ...need motor help

[djamps]

Hi guys, nice forum that I found! I hope to be visiting often.

I'm in the middle of restoring my old RC10 champ edition w/6gear tranny. It's got a Tekin 410s ESC and Yokomo Mach One 14tx2 modified motor. I recall back in the day, namely about 15 years ago, it ran this setup just fine w/out overheating or other issues. Runtime was decent.

I installed new brushes in the motor (trinity hard, serrated) and broke it in at low voltage, no load for about 10 minutes. The brushes appeared seated just fine. I installed it in the car with a 17 tooth pinion and 87 tooth spur (same setup I used to run with).

PROBLEM:
the runtime is TERRIBLE (about 5 or 6 minutes on a IB 4200 pack). The same battery on the rustler w/12t motor goes for about 15 minutes.

ANOTHER PROBLEM:
the positive motor brush is halfway gone after only two runs. I don't recall this being the case (low runtime and fast brush wear) when I used to bash back in the day. I was getting nearly the same runtime on 1300 SCR packs, and never had fast or uneven brush wear.

I was running it out on a ballfield (mostly dirt, some grass) and the ESC thermalled towards the end of the run. Also, the solder on the positive side of the endbell (where the brush connects) began to melt!

I know modified motors go through brushes faster, but this is crazy! I'm about to rebuild the motor again (this time a total teardown) and would like some tips. The only thing I cannot do is machine the comm...the lathe just isn't in the budget. I plan on cleaning it with a comm stick.

Is there any hope?

[rojna]

Sounds like you got a lot of dragggg in your transmision or wheels, take out the pinion gear and check that everything spins VERY smooooooothly back there, also check the bearing in the motor .............. if thats not the problem, then maybe your gearing is way off

[djamps]

Thanks for the reply.

I checked the tranny (actualy tore it down and rebuilt it) and it's all spinning very freely both before and after.

What gearing would you recommend? I can't increase the spur gear size (due to clearances).

What about the uneven brush wear?

[Asso_man!]

Thanks for the reply.

I checked the tranny (actualy tore it down and rebuilt it) and it's all spinning very freely both before and after.

What gearing would you recommend? I can't increase the spur gear size (due to clearances).

What about the uneven brush wear?

on every brushed motor, the positive pole always wears more so that's normal. You could try to use some long-life brushes if you don't have them already... I think you should change the motor, it seems it sucks too much power or maybe you have a problem with the speedo delivering too much power at one time... difficult to solve from here, hope it will help and by the way, WELCOM aboard

[mikedealer]

try a heavy spring on the Positive and a lighter on the negative (red+ and green- for trinity i believe..

another issue might just be the speed controller and the "newer" nimh battery technology, the speedo might just not like the batteries, maybe sounds stupid when i say it now but i had a old novak tempest i think it was and when i ran it with 3800's it ran awful

[FlyinGN]

nahhhh.. I ran new nmh batteries on a 25 year old Robert electronic controller on my HTS frog/RC10 and it run like a raped ape..

try a heavy spring on the Positive and a lighter on the negative (red+ and green- for trinity i believe..

another issue might just be the speed controller and the "newer" nimh battery technology, the speedo might just not like the batteries, maybe sounds stupid when i say it now but i had a old novak tempest i think it was and when i ran it with 3800's it ran awful

[Asso_man!]

nahhhh.. I ran new nmh batteries on a 25 year old Robert electronic controller on my HTS frog/RC10 and it run like a raped ape..

try a heavy spring on the Positive and a lighter on the negative (red+ and green- for trinity i believe..

another issue might just be the speed controller and the "newer" nimh battery technology, the speedo might just not like the batteries, maybe sounds stupid when i say it now but i had a old novak tempest i think it was and when i ran it with 3800's it ran awful

yep, that should be OK, unless your speedo has a dead FET... I also run an old Novak in my RC10 runner with 3700 Nimh batteries and it's ultra smooth, fast and even not hot with a modified 17turns... I really think your com should be skimmed

[wyldbill]

if you put in new brushes without cutting the com it will do that espically in a mod motor, if the endbell got that hot i would also suggest you get an alignment tool and re-align the brush hoods too. they could have shifted or warped slightly.

[Eau Rouge]

15 minutes on a 12-turn?


Even with 4200s, that's a lot of runtime to ask for.


Warped comm, tweaked brush hoods, bad or dirty motor bearings, cold solder joint... lots of things could cause runtime issues.

[superfly]

Definately a motor problem...that gearing shouldnt be to much for it. Did you set the timing on the motor correct after you tore it down? Try zero if possible. Too high a timing or too low (negative) timing will cause your heat problem. Look for broken wires, cracked magnets, and if your comm is very worn you might be getting lots of arcing and that creates extra heat i believe. Take emery paper and try to get the burn marks off the comm...Check the motor bearings to see if theyre siezed. Try a different motor to test your ESC if you have one...Sounds like motor to me though...good luck

[djamps]

try a heavy spring on the Positive and a lighter on the negative (red+ and green- for trinity i believe..

This might be a good lead. I had left the original springs on the motor for 15+ years in storage. They feel flimsy and weak. So harder (new) springs should slow the destruction of my brushes?

Definately a motor problem...that gearing shouldnt be to much for it. Did you set the timing on the motor correct after you tore it down? Try zero if possible.

Unfortunately there is no marking on the can, other than the line I drew to mark where it was originally.

Check the motor bearings to see if theyre siezed.

The bearing in the endbell seemed to be somewhat seized. I was able to free it up by working it with some light oil.

Try a different motor to test your ESC if you have one...Sounds like motor to me though...good luck

Tried the 12t rustler motor and it ran fine, like it does on the rustler w/no heat issues. So I'm certain the ESC is good and it doesn't have anything against the IB4200 cells.

I'm waiting for some new brushes and springs and a comm cleaning stick to have one more go at it before throwing in the towel on this motor.

Even with the heat/runtime issues, it still ran like a banshee out of hell!!! Beats the rustler w/stock 12t on the street.

[superfly]

I'd say your timing was set too high if you dont have any marks on the can and you were just guessing at it. You can try searching the internet on how to time your motors correctly, I've seen good sites but i dont have the links anymore. just rotate the endbell a few mm at a time till you dont get the heat prob anymore. You would want to rotate the end bell in the same direction as rotation...that will reduce the timing. By going against the rotation you advance it. So I think if you look down on the end bell then turning it clockwise should reduce the timing and counterclockwise should increase it. If you have the screws slightly loose you can run the motor and move the end bell at the same time to hear the difference in RPM as you rotate the endbell... I did this as a kid years ago before i even knew what motor timing was...I just heard it go faster and kinda set it by sound...although if you go too far watch out!!! It's not going to like that hahahaha Good luck...

BTW I think zero timing should be when your timing mark on the endbell is positioned between the magnets...you know the space between the two magnets when looking inside the can...i think if your mark is positioned there you should be close...I think that right I could be wrong though????

oh yeah and i dont think your brush springs are the prob...weaker springs will reduce the rpms and extend the brush life...if theyre too weak the motor just stops all the time and the car will need a nudge to get running...like having a hung brush...I've used 20yr old springs and havent had probs with them...

[superfly]

http://www.hobbytalk.com/bbs1/showthread.php?t=126994

I found everything you need to know about that motor!!!