View Full Version : damage to motors

03-07-2010, 08:37 PM
hey guyz, i made a robot for the roborace project.The robot is very fast and smooth in control.The problem arose on second day of completion..one of the motors got damaged,by which i mean that shaft of the motor was detached from the motor itself..On opening the motor i found that one of the gears was broken into 2 pieces..How it got broken?i think there are 2 reasons...tell me which one is most probable:
1.by giving higher voltage than rated one(i gave 22v by mistake)
2.due to bad wheel alignment
i have lost 2 motors in same way...one on the event and one just before one day from the event....
I have another question...Can motors be damaged if voltage is given to them (about 6v higher than rated voltage) for short time say 30 minutes?

03-07-2010, 09:05 PM
Over voltage will burn the coils. Gears breaking into two is mechanical damage, most probably wheel misalignment, too much friction, gear misalignment, and horrible testing terrain....and ohhh... Ultra cheap gearbox.

See what fits your case.


03-07-2010, 09:08 PM
i feel all of them.....thanx for advice...but is the problem may arose due to over voltage?

03-07-2010, 09:46 PM
As long as you are not directly powering your motors (i.e. using a motor driver), You are more likely to blow up the IC before your motors.
But, if you do power your motors directly(which is most likely your case), the damage will be more nasal than visual (i.e. the burning smell of either the motors or the surrounding plastic), 30 minutes of 6V more than enough to cause permanent damage.

But that definitely wont break gears. That is mechanical stress, not related to voltage.


03-07-2010, 10:24 PM
thanx a lot rao

03-08-2010, 11:46 AM
"for short time say 30 "


In Engineering and Science 30 min is not SHORT Time !!!

You can pulse an LED with 12v without any damage if the pulse is short (in Millisecond)

Also these days gear breaking is a common issue due to cheap gear boxes.

03-08-2010, 12:57 PM
post a pic so we can make better guesses ...

03-08-2010, 05:56 PM
When you give high voltages the coil present inside becomes partially short( the covering over coil gets removed & it shorts), this is due to heat generated.

I suppose the gear must be of plastic.It is always advised to use nylon or metal gears(if possible).The gears get jammed easily or even break as in your case. Breaking of gear is a mechanical problem as said above.

03-08-2010, 07:47 PM
i dont know whether they are cheap for u or not but for me it costed Rs 180/- per motor...got from lajpat rai

03-08-2010, 07:56 PM
Let me guess, Everest?


03-08-2010, 08:03 PM
no man!!...some other no need to guess ...it is 472

03-08-2010, 08:27 PM
No matter what shop, but the quality sounds low.


03-16-2010, 12:29 AM
I think this shop is next to guru tranformer shop(popular one in lajpath rai) I have seen a few gear motors here , why not use car wiper motor/window motors really poerful and good quality


03-16-2010, 12:00 PM
Yes this shop is next to Guru Transformer Shop.Wiper motors are powerful but they are big and heavy too.I once saw a wiper motor used as steering on a robot but the bot never worked as the driving motors were lame.


No idea about window motors,