Hi,
I want to run this motor @ 36v. Before doing so I want to drill some holes in the body, and widen to holes in the top and bottom to improve air flow to keep the motor runnig cool.
Maybe even connect a PC fan to get more air flowing through the motor.
I'm afraid of taking this apart, then being unable to put it back together.
Has anyone taken on of these apart? Is there anything I should be aware of?
Does anybody have any experience with the Bosch GPA 24v 750w motor? Where can I get one for a reasonable price?
Thanks,
Dave S.
It can be difficult to get the brushes back in right on that style motor after you open it up, as access is tight and they are spring loaded.
These guys have some good high power motors, Scroll down. the 1000 watt 36V and 48V are good motors.
http://tncscooters.com/partsdb.php?type=ES
Don't be afraid, this is easy. you'll need to find a way to hold the brushes in place as you re-assemble it. I used a couple of safety pins.
I wouldn't worry about drilling holes in the body, if there's an internal fan, doing this could actually take cooling airflow away from where its needed most, the commutator.
if you do enlarge the holes that are already there, try only doing the holes on the output end first. this should increase the speed and cooling effectivness of the air entering at the commutator end.
I know of these motors. My current motor, and most of the other components on my e-scooter were purchased from TNC.
I do not want to buy a new motor because I live abroad, and the shipping and taxes make it not worth while.
I don't understand why they made the motor's brushes so hard to replace. On other motors I know the brushes can be replaced without taking the motor apart, just by opening a cap.
The guy below wrote that it is not that difficult to put the motor back together.
I came across another thread in this forum where a guy built a recumbent e-bike with a brushless RC plane motor. These motors are much more efficient than the brushed permanent magnet, can take a higher range of voltages, and run at higher speeds.
I am looking at replacing my motor with one of these. Before I do this I need to find out if they have enough torque to run the scooter without down gearing.
Thanks anyway.
Hi Ray,
Can you elaborate how you took this motor apart, and how you held the brushes while re-assembling?
How did you pull the pins out once the motor was aseembled?
Is there an internal fan in the motor? I did'nt notice any air flow.
What good is widening the exit holes if the air intake holes remain their original size?
Thanks.
First I'll say that I don't really remember if there's an internal fan in this motor.
If there is, widening the exit holes gives the air being pushed (pulled) by the fan an easier escape, lowering the pressure inside the cylinder. When the pressure inside is lower, the speed of the air coming in increases the same as if the pressure outside were higher. if you were to restrict this incoming air, the speed would increase further. kind of like putting a nozzle on a garden hose, the stream goes farther when the hole is smaller because there's a bigger difference between inside and outside pressures.
as far as how to reassemble, the motor is made of a cylinder with magnets glued to the inside, the rotor with the windings, and two end caps one front and one back. I'll call the end with the brushes the back.
First thing is you should make a mark where both the front and back end caps meet the cylinder so you can get it oriented correctly when you put it back together. engrave this mark, or use a grease pen, a pencil or permanent marker will rub off. This is important, because it's possible to reassemble the motor with the cylinder rotated 90 degrees and the motor will run backwards.
the whole thing is held together by two long screws that run from back to front. remove these screws and pull it apart (carefully, the magnets are strong).
as the brush end of the motor is removed, the brushes will fall out of their holders in the end cap.
There should be some mesh or screen covering the intake holes. what I did was push each brush as far into its retainer as it would go, then insert a safety pin from the outside of the motor, through the wire for the brush, and into some part of the brush retainer so it will be held in place during reassembly.
as I remember, it took a couple of tries with the pin in different positions before I found one that worked.
when putting it back together, check the mark you made in the beginning, and (again carefully the magnets are strong) slide the cylinder over the rotor. replace the brush end, check your mark again, and replace the long screws. after it's all back together, pull the safety pins out and the brushes will snap into place on the commutator.