R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric On-Road

Reply
 
Thread Tools Search this Thread
Old 01-07-2010, 12:46 AM   #1
Tech Master
 
Join Date: Jul 2009
Posts: 1,039
Trader Rating: 4 (83%+)
Default Do Brushed Motors lose power/torque over time

Do Brushed Motors loas power.touque over time? I don not race, I drift. I think it's easy on the car and the RPM slower. Will my motor get weak until it eventual stops running? WIll it keep it's power? This is going on a Sprint 2, will it lose it's power fast?
DriftWoof is offline   Reply With Quote
Old 01-07-2010, 01:59 AM   #2
Tech Elite
 
WheelNut's Avatar
 
Join Date: Jan 2003
Location: Edmonton, Ab
Posts: 3,210
Trader Rating: 5 (100%+)
Send a message via MSN to WheelNut
Default

Yeah they lose power if you don't maintain them. You need to change the brushes and true to commutator on a lathe in addition to periodic cleaning. Overheating is also very bad for brushed motors, so make sure to keep your motor temps below 140-150ºF at the end of a run to avoid burning the comm, brushes or weakening the magnets.
__________________
•Brad Comis
WheelNut is offline   Reply With Quote
Old 01-07-2010, 02:36 AM   #3
Tech Master
 
Join Date: Jul 2009
Posts: 1,039
Trader Rating: 4 (83%+)
Default

Quote:
Originally Posted by WheelNut View Post
Yeah they lose power if you don't maintain them. You need to change the brushes and true to commutator on a lathe in addition to periodic cleaning. Overheating is also very bad for brushed motors, so make sure to keep your motor temps below 140-150ºF at the end of a run to avoid burning the comm, brushes or weakening the magnets.
I remember I ran an HPI Firebolt 15T a long time, never did a thing to it. I've also run other motors without doing anything to them. Modified or not no matter how long I used them they ran. DO brushed motors lose power to point and the just settle there? Or do they lose power until they don't run no more?
DriftWoof is offline   Reply With Quote
Old 01-07-2010, 02:53 AM   #4
Tech Master
 
heretic's Avatar
 
Join Date: Aug 2006
Location: europe
Posts: 1,105
Default

Quote:
Originally Posted by DriftWoof View Post
do they lose power until they don't run no more?
Yes. And they start weakening as soon as you have trued them/ changed the brushes, or almost. Back in the days when I raced 17x2 I trued my comm every pack and cleaned the brushes, that's 5 min of use. That is a bit boring and time comsuming but back then we didn't have silver or Q-brushes, which last longer and are more gentle with the comm.

If your commutator looks any different than a uniform/homogenous glossy copper color, it is probably ruined. If your brushes seem to have become blue/purple/red, they are toasted. And with the use you decribed, it is very likely to be the case.

Closed endbells such as the 15t hpi are different because they are sh*tty by design. You probably never used more than 60% of what they could offer, but to get to th 100% would require so many attentions ( among which : veeery, very long break-in, constant cleaning, oiling of the bushes, never make it too hot, find the perfect FDR, etc) that it is not even worth trying.

Just save some money and buy yourself a cheap entry level brushless combo. Buying the tools needed to take care of brushed motors would cost you twice more and bore you to death, eventually making you tired of the hobby.

sorry for my less-than-perfect english, I think you get the point.
heretic is offline   Reply With Quote
Old 01-07-2010, 03:23 AM   #5
Tech Master
 
Join Date: Jul 2009
Posts: 1,039
Trader Rating: 4 (83%+)
Default

Quote:
Originally Posted by heretic View Post
Yes. And they start weakening as soon as you have trued them/ changed the brushes, or almost. Back in the days when I raced 17x2 I trued my comm every pack and cleaned the brushes, that's 5 min of use. That is a bit boring and time comsuming but back then we didn't have silver or Q-brushes, which last longer and are more gentle with the comm.

If your commutator looks any different than a uniform/homogenous glossy copper color, it is probably ruined. If your brushes seem to have become blue/purple/red, they are toasted. And with the use you decribed, it is very likely to be the case.

Closed endbells such as the 15t hpi are different because they are sh*tty by design. You probably never used more than 60% of what they could offer, but to get to th 100% would require so many attentions ( among which : veeery, very long break-in, constant cleaning, oiling of the bushes, never make it too hot, find the perfect FDR, etc) that it is not even worth trying.

Just save some money and buy yourself a cheap entry level brushless combo. Buying the tools needed to take care of brushed motors would cost you twice more and bore you to death, eventually making you tired of the hobby.

sorry for my less-than-perfect english, I think you get the point.
I ordered a Yeah Racing 4300KV 9T Brushless Motor for my EZRUN 35AMP Brushless ESC. After reading that, I am don't with Brushed Motors forever. Just like TV Tubes.
DriftWoof is offline   Reply With Quote
Old 01-07-2010, 03:27 AM   #6
Tech Elite
 
rough512's Avatar
 
Join Date: May 2002
Posts: 3,454
Trader Rating: 12 (100%+)
Default

over time, motors will lose some of their torque as the magnets weaken from being subjected to heat. Brushed motor cans can be easily remagnetized by using magnet zappers. Brushless rotors are not readily remagnetized since these need more powerful magnetizers not readily available to hobbyists.
rough512 is offline   Reply With Quote
Old 01-07-2010, 03:37 AM   #7
Tech Master
 
heretic's Avatar
 
Join Date: Aug 2006
Location: europe
Posts: 1,105
Default

Quote:
Originally Posted by rough512 View Post
over time, motors will lose some of their torque as the magnets weaken from being subjected to heat. Brushed motor cans can be easily remagnetized by using magnet zappers. Brushless rotors are not readily remagnetized since these need more powerful magnetizers not readily available to hobbyists.
mmh, seriously, how accessible are these zappers ? In more than 10 years in rc cars I never saw one other than on picture. I never even knew someone who owned one, an I'm not even sure the very best drivers I met ever used one.

Quite unrealistic for someone like Driftwoof. Furthermore if you start worrying of the magnets in your brushed motor, you're already pretty skilled. For example it means you already have re-bored ( drilled/reamed ?) your bearing housing to have perfect bearing alignment(+2000 RPM) , you already have a perfect FDR/brushes/springs combo, etc.



Driftwoof : good choice! Hope you're already addicted to RC ! But can your ESC handle the motor you plan on using ? dunno, just wondering. Perhaps the 60 amps ESC would have been more appropriate.

In any case, check the temps every single minute for your first runs at least, it will prevent you from melting anything.
heretic is offline   Reply With Quote
Old 01-07-2010, 05:36 AM   #8
Tech Elite
 
Toh WL's Avatar
 
Join Date: May 2006
Location: Setapak
Posts: 3,567
Trader Rating: 6 (100%+)
Default

How does magnet zapper looks like? To me I just change the rotor when I notice degraded speed.
Toh WL is offline   Reply With Quote
Old 01-07-2010, 05:41 AM   #9
Tech Regular
 
Dragula426's Avatar
 
Join Date: May 2008
Location: USA
Posts: 351
Trader Rating: 4 (100%+)
Default

Quote:
Originally Posted by heretic View Post
mmh, seriously, how accessible are these zappers ? In more than 10 years in rc cars I never saw one other than on picture. I never even knew someone who owned one, an I'm not even sure the very best drivers I met ever used one. .
Check: Dirtoval.com

There have been a few for sale recently on Dirtoval.com in the classifieds under the forums. The motor can zappers are a little tougher to find than the battery zappers, but they are still around. If you had to go fast back in the day, access to or owning these items was pretty much a given.

Seen them, used them, went faster knowing people who had them. The battery zappers were the best. If you didn't get the battery in there just right, you were in for a very bright surprise.

http://dirtoval.com/forums/showthrea...ghlight=zapper

http://dirtoval.com/forums/showthrea...ghlight=zapper
__________________
Team Tekin
Jeffery Racing Concepts
Little 'O' Speedway
Extreme Graffix
Dragula426 is offline   Reply With Quote
Old 01-07-2010, 06:56 AM   #10
Suspended
 
Join Date: Oct 2009
Location: FLA
Posts: 415
Trader Rating: 2 (75%+)
Default

Quote:
Originally Posted by rough512 View Post
over time, motors will lose some of their torque as the magnets weaken from being subjected to heat. Brushed motor cans can be easily remagnetized by using magnet zappers. Brushless rotors are not readily remagnetized since these need more powerful magnetizers not readily available to hobbyists.
why would the average user that already running on the cheap be interested in obtaining a magnet zapper ?
justanotherdude is offline   Reply With Quote
Old 01-07-2010, 09:39 AM   #11
Tech Elite
 
niznai's Avatar
 
Join Date: Feb 2009
Location: All over the place
Posts: 2,940
Default

Quote:
Originally Posted by DriftWoof View Post
I remember I ran an HPI Firebolt 15T a long time, never did a thing to it. I've also run other motors without doing anything to them. Modified or not no matter how long I used them they ran. DO brushed motors lose power to point and the just settle there? Or do they lose power until they don't run no more?
I don't think you ran that motor for a very long time though. If nothing else goes wrong, then at least the brushes wear down to the point they just don't push against the comm enough to turn the rotor over.

Brushed motors though lose performance very quickly and that is why you need to change brushes, true comms, polish bushings (in stock) and generally speaking do a lot of maintenance. Knowing that very well, I would guess you aren't that much concerned about performance after all.
__________________
Team Greasy Weasel

The best upgrade to any car is some driver skill.
niznai is offline   Reply With Quote
Old 01-08-2010, 01:58 AM   #12
Tech Master
 
Join Date: Jul 2009
Posts: 1,039
Trader Rating: 4 (83%+)
Default

I already have a 9T easy run, i have a black one now too though and they run nice and real cool on a 35 ezrun esc even when going nuts with it.
DriftWoof is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
what happems when brushless takes over? TAMIYAMANUK Electric On-Road 207 09-15-2006 04:49 PM
Novak Super Sport Brushless Motor System glide 1 Electric On-Road 437 03-27-2004 12:03 AM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 03:57 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net