Powabyke brush holder plate

[Geoff Lee]

Hi Guys

Me again!!!
I have an old Powabyke with rear wheel hub drive.
Would one of you electrical wizards please tell my why the motor brush holder plate has elongated adjustment slots?
Thanks Geoff

 

[tringmotion]

If you get stuck Bernie at Bikes and batterys Ltd can help with this

Sent from my E6853 using Tapatalk

 

[Live_Steam_Mad]

For advancing or retarding the brush timing to give more power / speed or less current draw ?? We used to have brushed motors with adjustable timing in RC cars.

Regards,

Alistair G.

 

[Geoff Lee]

For advancing or retarding the brush timing to give more power / speed or less current draw ?? We used to have brushed motors with adjustable timing in RC cars.

Hi Alistair
Thanks for your reply. I guess as the motor has permanent magnets for field the re-positioning of the brushes would affect the phasing. However, it is not possible to access this adjustment once the motor is assembled to run. Is there some sort of rational which says "clockwise for more power" or "anti-clockwise for less current draw" obviously I would need to determine the rotation direction??
There is quite a lot of adjustment available, getting on for 20mm. It is a pity it cannot be adjusted with the motor running to gauge the effect with a meter in circuit.
Geoff[/QUOTE]

 

[Live_Steam_Mad]

Hi Geoff,

As regards your question, I don't know about your specific motor, but here is a brushed motor instruction manual linked to below that shows the direction of rotation and the brush timing adjustments, on a motor that I am quite familiar with (Tamiya / Mabuchi "Technigold") ;-

http://www.robobugs.net/wordpress/wp-content/files/RX-540VZ_Technigold_Motor_Manual_50290.pdf

At least it shows the "principle".

RC cars went brushless quite a long time ago now. I find my background in RC buggies (soldering, batteries, ESC, motors) to be quite helpful in understanding these electric bikes that we are using.

I find it interesting that my Brother's Giant Lafree Comfort Twist ST e-bike uses a sensorless brushless crank drive motor - sensorless at least as far as I can tell, since I can feel it "cogging" at low speed (cogging is an RC car terminology, meaning no fine control of throttle/speed at that particular speed), it's torque sensed. Whereas my own Elops 500 uses a brushless rear hub motor with cadence sensed pedals, where I can't tell if the motor itself is sensored or sensorless as I can't feel any cogging (yet) on the short test rides that I did so far.

Regards,

Alistair G.

 

[Geoff Lee]

Thanks for all that Alistair, that is great info indeed.
I have certainly never come across a motor with adjustable brush gear before.

Most of my RC experience is brushless, mainly planes.

Thanks again for going to the trouble of replying.
Geoff