RCCrawler Forums

JeremyH · 02-20-2010, 07:20 PM

I am having an issue with one of my motors (Fantom Blitz 35T) on my dual motor setup (HH TQ ESC, Punk Dig) that has about one season on it (regular brush and spring replacement). The front motor seems to hang up at low throttle...reminiscent of a stuck brush. It will also periodically hang when turning the wheels. I have pulled apart the axles (Bullys) and made sure that none of the gears are binding and that the bearings are in good shape...no problem there. I pulled apart the motor and cleaned and oiled the can and all bearings. I cleaned the armature and comm. The comm is in good shape (brush marks are even) and I put new brushes and springs in during the rebuild. I ran the motor before I reinstalled it on the truck and the problem seemed to still be present (intermittently). After everything was put back together, the problem still exists. I cant figure out what is going on.

Any help and input is appreciated.

Jeremy

rock hard · 02-21-2010, 04:42 AM

is it a for sure hang up at low rpm?or spuratic
and when turning its spuratic?

when you tore the axle and motor apart to clean/inspect
did you actually check the bearings for a rough spot?
my insticts would tell me to check every bearing in the axle/motor in my fingers for any roughness,and I would also want to check the mags inside the can real close for anything that may be hiding/stuck to the mags.
very small metal shavings ect. that may be missed with a quick look.

but if all in the motor looks good,I suspect a bad bearing.

good luck

JeremyH · 02-21-2010, 05:25 AM

Paul, thanks for the reply. I didnt pull the bearings out of the case, just put my finger on them and twisted. Maybe, since the problem existed while I ran the motor when it was removed from the vehicle, that one of the bearings in the motor is bad. I dont think I have ever seen that before, but I supposed anything is possible. I need to tear the motor apart again and perform a more thorough inspection...

EeePee · 02-21-2010, 09:42 AM

Swap motors front to back yet?

JeremyH · 02-21-2010, 10:18 AM

Nope. Would that make much of a difference (other than transferring the problem to the rear)? BTW, my punk dig is located in the middle of the truck...the motor leads are almost the same length.

I did just pull the motor apart and both bearings seem to be in perfect condition.

Thanks!

killswitch · 02-21-2010, 10:28 AM

check the inside of the brush hoods for burrs. the brushes should move effortlessly in the brush hoods. Also, you've said that you replace the brushes and springs... but have you ever cut the comm? Replacing brushes only goes so far until the comm is worn to an hour glass shape. The brush face cant completely contact the comm and the result could be loss of power/ poor running.

edit... 1 more thing. make sure the brush hoods havent taken a hit knocking them out of shape.

ScalerLover · 02-21-2010, 11:00 AM

Quote:

Originally Posted by EeePee

Swap motors front to back yet?

I think EeePee's comment was to help actually narrow it down to the motor its self, if you swap them and the problem moves to the rear, then you are for damn sure its the motor.

EeePee · 02-21-2010, 11:27 AM

Yes, exactly.

JeremyH · 02-21-2010, 12:04 PM

Quote:

Originally Posted by ScalerLover

I think EeePee's comment was to help actually narrow it down to the motor its self, if you swap them and the problem moves to the rear, then you are for damn sure its the motor.

Ahh....ok. The only thing that I have done is to remove the motor and run it detached from the gearcase. The problems persisted. However, I guess that leaves everything from the motor back to the ESC that could be causing this problem. I will swap the motors this evening.

Quote:

Originally Posted by killswitch

check the inside of the brush hoods for burrs. the brushes should move effortlessly in the brush hoods. Also, you've said that you replace the brushes and springs... but have you ever cut the comm? Replacing brushes only goes so far until the comm is worn to an hour glass shape. The brush face cant completely contact the comm and the result could be loss of power/ poor running.

edit... 1 more thing. make sure the brush hoods havent taken a hit knocking them out of shape.

Nope, I have not cut the comm. I dont have a lathe. The comm appears to be in good shape (good brush contact across the width and centered on the comm). I also dont see any misshaped areas....

I will inspect the hoods this evening and report back.

Would pictures of said motor (comm and arm) help with the diagnosis??

JeremyH · 02-21-2010, 12:35 PM

JeremyH · 02-21-2010, 01:25 PM

Ok....as a small test before I went ahead with a full front/rear motor swap, I swapped everything but the endbells. Result: the problem is now in the rear. So, that means that there should not be a problem with my electronics (ESC, Dig, Endbells).....so what could be the issue? I didnt want to only swap the arms....but I am thinking that I should try that next. Sound like a plan?

ib99rt · 02-21-2010, 01:41 PM

I had this problem once, and it turned out to be that the armature wire was not making good contact to the mounting point below the comm. Cleaned and added a little soldier and problem solved. Hope this helps

JeremyH · 02-21-2010, 01:51 PM

After a LOT of parts swapping, it HAS to be something wrong with the arm.

Quote:

Originally Posted by ib99rt

I had this problem once, and it turned out to be that the armature wire was not making good contact to the mounting point below the comm. Cleaned and added a little soldier and problem solved. Hope this helps

Thank you. I think I have narrowed it down to the arm. I am going to try what you suggested.

JeremyH · 02-21-2010, 02:14 PM

ib99rt, I do believe that solved the problem. I will get everything bolted back together and take it on a few test runs.

Thanks!

RickM · 06-25-2011, 12:28 PM

Alright. This has me thinking. I have been having some inconsistant motor issues myself. I made some big changes that are making this hard fomr me to figure out. I went to a 4pl and also went to a smaller battery.

Here is my setup.
duel mamba micro's
Brood 35t motors with everything shoved in a novak 2 mag can.
3s 480 packs.
Bec is pulling straight to the servo. Mamba micro's are running similar length wires. I have checked the wiring but have not checked gear mesh to see if something has slipped. I will do that tonight.

I did recently cut the comms but I did NOT put new brushes in.

I did notice today thay my motor brushes and brush wires sure were crammed around and stuff. That did not look pretty, and when I pulled it apart some it might have helped give it what looked like a little bit of consistency. What it appears to be doing is almost like giving me two different gears.

Jeremy, was this similar to your experience?

indiana mudcat · 06-25-2011, 01:15 PM

I have a 35t brood that does the same thing, started after I got in a bind in the middle of a gate and wouldn't say give. Smoked a 850 45C TP 3s pack and started rolling smoke from the motor, the deans almost burnt me when I unplugged it. Drove almost like new after it cooled down, just an occasional freeze, but got worse after the next big bind and was undriveable. The local motor guru thinks I burnt a wind cause the comm and brushes look fine. I need to send it back to EddieO to have him look at it, but the issue is entirely my fault.

JohnRobHolmes · 06-26-2011, 08:46 AM

Quote:

Originally Posted by RickM

Alright. This has me thinking. I have been having some inconsistant motor issues myself. I made some big changes that are making this hard fomr me to figure out. I went to a 4pl and also went to a smaller battery.

Here is my setup.
duel mamba micro's
Brood 35t motors with everything shoved in a novak 2 mag can.
3s 480 packs.
Bec is pulling straight to the servo. Mamba micro's are running similar length wires. I have checked the wiring but have not checked gear mesh to see if something has slipped. I will do that tonight.

I did recently cut the comms but I did NOT put new brushes in.

I did notice today thay my motor brushes and brush wires sure were crammed around and stuff. That did not look pretty, and when I pulled it apart some it might have helped give it what looked like a little bit of consistency. What it appears to be doing is almost like giving me two different gears.

Jeremy, was this similar to your experience?

Sounds like a hanging or stuck brush is most likely. Get some new ones on there and be sure they slide free.

Quote:

Originally Posted by indiana mudcat

I have a 35t brood that does the same thing, started after I got in a bind in the middle of a gate and wouldn't say give. Smoked a 850 45C TP 3s pack and started rolling smoke from the motor, the deans almost burnt me when I unplugged it. Drove almost like new after it cooled down, just an occasional freeze, but got worse after the next big bind and was undriveable. The local motor guru thinks I burnt a wind cause the comm and brushes look fine. I need to send it back to EddieO to have him look at it, but the issue is entirely my fault.

Probably got something like a little rock inside the motor that bound it up, then you tried to power through and smoked a wind.

Manning · 06-26-2011, 10:24 AM

Back in the day, I'd have motors that would start getting hot, or run sporadically, and no amount of comm cutting or brush replacement would fix it. Throw a new arm in the can and it would run fine. The original arm apparently would have a short or open wind. No way to fix it.

igbandy · 06-26-2011, 11:25 AM

Quote:

Originally Posted by indiana mudcat

I have a 35t brood that does the same thing, started after I got in a bind in the middle of a gate and wouldn't say give. Smoked a 850 45C TP 3s pack and started rolling smoke from the motor, the deans almost burnt me when I unplugged it. Drove almost like new after it cooled down, just an occasional freeze, but got worse after the next big bind and was undriveable. The local motor guru thinks I burnt a wind cause the comm and brushes look fine. I need to send it back to EddieO to have him look at it, but the issue is entirely my fault.

Sounds like the windings have earthed/shorted out.

JeremyH · 06-26-2011, 03:58 PM

Quote:

Originally Posted by RickM

Jeremy, was this similar to your experience?

Well, mine would just cut in and out.

My problem ended up being a bad solder on the arm. A bit later, I actually killed that motor. I am not sure how it heated up so much, but I actually slung all of the solder off of the arm and it was stuck to the inside of the can. I am not sure how I did this without killing the battery or magnets first, but that is what happened.

I dont usually replace the brushes on my motors after cleaning or cutting, I just inspect for damage and clean the brush, then reinstall.

02-20-2010, 07:20 PM	#1
JeremyH I wanna be Dave Join Date: Sep 2005 Location: Houston, TX Posts: 16,952	Motor Issue I am having an issue with one of my motors (Fantom Blitz 35T) on my dual motor setup (HH TQ ESC, Punk Dig) that has about one season on it (regular brush and spring replacement). The front motor seems to hang up at low throttle...reminiscent of a stuck brush. It will also periodically hang when turning the wheels. I have pulled apart the axles (Bullys) and made sure that none of the gears are binding and that the bearings are in good shape...no problem there. I pulled apart the motor and cleaned and oiled the can and all bearings. I cleaned the armature and comm. The comm is in good shape (brush marks are even) and I put new brushes and springs in during the rebuild. I ran the motor before I reinstalled it on the truck and the problem seemed to still be present (intermittently). After everything was put back together, the problem still exists. I cant figure out what is going on. Any help and input is appreciated. Jeremy

02-21-2010, 10:28 AM	#6
killswitch RCC Addict Join Date: Jun 2005 Location: St. Albans Posts: 1,441	check the inside of the brush hoods for burrs. the brushes should move effortlessly in the brush hoods. Also, you've said that you replace the brushes and springs... but have you ever cut the comm? Replacing brushes only goes so far until the comm is worn to an hour glass shape. The brush face cant completely contact the comm and the result could be loss of power/ poor running. edit... 1 more thing. make sure the brush hoods havent taken a hit knocking them out of shape. Last edited by killswitch; 02-21-2010 at 10:32 AM.

02-21-2010, 04:42 AM	#2
rock hard dnf Join Date: Sep 2009 Location: Under a big fkn rock. Posts: 1,901	is it a for sure hang up at low rpm?or spuratic and when turning its spuratic? when you tore the axle and motor apart to clean/inspect did you actually check the bearings for a rough spot? my insticts would tell me to check every bearing in the axle/motor in my fingers for any roughness,and I would also want to check the mags inside the can real close for anything that may be hiding/stuck to the mags. very small metal shavings ect. that may be missed with a quick look. but if all in the motor looks good,I suspect a bad bearing. good luck

02-21-2010, 05:25 AM	#3
JeremyH I wanna be Dave Join Date: Sep 2005 Location: Houston, TX Posts: 16,952	Paul, thanks for the reply. I didnt pull the bearings out of the case, just put my finger on them and twisted. Maybe, since the problem existed while I ran the motor when it was removed from the vehicle, that one of the bearings in the motor is bad. I dont think I have ever seen that before, but I supposed anything is possible. I need to tear the motor apart again and perform a more thorough inspection...

02-21-2010, 09:42 AM	#4
EeePee MODERATOR™ Join Date: Jul 2004 Location: Ohio Posts: 18,928	Swap motors front to back yet?

02-21-2010, 10:18 AM	#5
JeremyH I wanna be Dave Join Date: Sep 2005 Location: Houston, TX Posts: 16,952	Nope. Would that make much of a difference (other than transferring the problem to the rear)? BTW, my punk dig is located in the middle of the truck...the motor leads are almost the same length. I did just pull the motor apart and both bearings seem to be in perfect condition. Thanks!

02-21-2010, 11:27 AM	#8
EeePee MODERATOR™ Join Date: Jul 2004 Location: Ohio Posts: 18,928	Yes, exactly.

02-21-2010, 12:35 PM	#10
JeremyH I wanna be Dave Join Date: Sep 2005 Location: Houston, TX Posts: 16,952

02-21-2010, 01:25 PM	#11
JeremyH I wanna be Dave Join Date: Sep 2005 Location: Houston, TX Posts: 16,952	Ok....as a small test before I went ahead with a full front/rear motor swap, I swapped everything but the endbells. Result: the problem is now in the rear. So, that means that there should not be a problem with my electronics (ESC, Dig, Endbells).....so what could be the issue? I didnt want to only swap the arms....but I am thinking that I should try that next. Sound like a plan?

02-21-2010, 01:41 PM	#12
ib99rt Pebble Pounder Join Date: Dec 2009 Location: Who Dat Louisiana Posts: 115	I had this problem once, and it turned out to be that the armature wire was not making good contact to the mounting point below the comm. Cleaned and added a little soldier and problem solved. Hope this helps

02-21-2010, 02:14 PM	#14
JeremyH I wanna be Dave Join Date: Sep 2005 Location: Houston, TX Posts: 16,952	ib99rt, I do believe that solved the problem. I will get everything bolted back together and take it on a few test runs. Thanks!

06-25-2011, 12:28 PM	#15
RickM RCC Addict Join Date: Jan 2010 Location: Dallas Posts: 1,848	Alright. This has me thinking. I have been having some inconsistant motor issues myself. I made some big changes that are making this hard fomr me to figure out. I went to a 4pl and also went to a smaller battery. Here is my setup. duel mamba micro's Brood 35t motors with everything shoved in a novak 2 mag can. 3s 480 packs. Bec is pulling straight to the servo. Mamba micro's are running similar length wires. I have checked the wiring but have not checked gear mesh to see if something has slipped. I will do that tonight. I did recently cut the comms but I did NOT put new brushes in. I did notice today thay my motor brushes and brush wires sure were crammed around and stuff. That did not look pretty, and when I pulled it apart some it might have helped give it what looked like a little bit of consistency. What it appears to be doing is almost like giving me two different gears. Jeremy, was this similar to your experience?

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06-25-2011, 01:15 PM	#16
indiana mudcat RCC Addict Join Date: Jul 2009 Location: reelsville Posts: 1,871	I have a 35t brood that does the same thing, started after I got in a bind in the middle of a gate and wouldn't say give. Smoked a 850 45C TP 3s pack and started rolling smoke from the motor, the deans almost burnt me when I unplugged it. Drove almost like new after it cooled down, just an occasional freeze, but got worse after the next big bind and was undriveable. The local motor guru thinks I burnt a wind cause the comm and brushes look fine. I need to send it back to EddieO to have him look at it, but the issue is entirely my fault.

06-26-2011, 10:24 AM	#18
Manning RCC Addict Join Date: Nov 2006 Location: Lowell, Arkansas Posts: 1,307	Back in the day, I'd have motors that would start getting hot, or run sporadically, and no amount of comm cutting or brush replacement would fix it. Throw a new arm in the can and it would run fine. The original arm apparently would have a short or open wind. No way to fix it.

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Thread: Motor Issue