Can someone explain "timing" and how/why it is necessary?

[old phart]

I know how to time gasoline and diesel engines, 2-stroke and 4-stroke.

How do you time an electric motor? What is timing on an electric motor?

Thanks! http://www.rccaraction.com/ubb/biggrin.gif

[TOTAL CARNAGE]

Advance timing = more rpm, less torque
retard timing = more torque, less rpm
Remember, rpm isn't everything and in the case of a tight road course, offroad, Monster trucks torque can be more important!

[JoeTheShmoe]

i thought you NEVER wanted to use retard timing unless that motor is running backwards, because it just makes the motor run hotter??

[Isky]

apparently that doesnt apply...mwahahaha

[TOTAL CARNAGE]

You are right Joe you should never run less than 0 deg. timing.
I should have said "less timing" gives more torque.

[SirSpeedy]

Originally posted by TOTAL CARNAGE:
Advance timing = more rpm, less torque
retard timing = more torque, less rpm
Remember, rpm isn't everything and in the case of a tight road course, offroad, Monster trucks torque can be more important!

That is not always the case. Most motors have a sweet spot in which they perform best. This sweet spot can only be found by trial and error on a dyno. I have seen power, torque, efficiency, and RPM rise by advancing the timing from say 15 deg to 20 deg.

Marking the motor when you disassemble it, and putting it back where the builder put it is the saftest bet.

See ya...

[RCJunkie]

RCCA August 2000 there was a sweet article on mod motors that explained everything and also had dyno results for about 50 different motors. Maybe you could find a back issue or a friend that has a copy.

[Nairb]

Timing is basically the angle at which the brushes are at compared to the magnets in the can (when looking at the endbell). It has to do with the timing of when the brushes give electricity to (and hence, magnetize) the windings in relation to the magnetic field in the can. That's what I've figured out myself. I don't know much else about it, so I pass the baton to someone else...

[This message has been edited by Nairb (edited 03-03-2001).]

[rvrrun]

The ideal timing angle changes as the load and RPM of an electric motor changes. The magnetic field in the armature is dynamic and changes in relation to the magnetic field in the can. As the armatures magnetic field increases, and interacts with the magnetic field in the can and this field is rotated. This is where the timing of the brushes/endbell come into play and should be rotated propotionally to the changing magnetic field of the motor. To further complicate, as the RPM of the motor increases, the armature coils need to be fully charged earlier in order to react optimally with the field magnets. Unfortuantely, as I stated before, this effect is dynamic and as such no motor can be perfectly timed without the timing itself being dynamic. Saying more timing=more rpm, less torque and vice versa is not always correct as it is very possible to give a motor too much timing. A dyno can help in finding the optimal timing for an indvidual motor, but since the load on a motor cannot be accurately depicted throughtout its RPM range, is less than perfect. A properly timed motoer will show a minimum amount of arching at the comm.

MS

[This message has been edited by rvrrun (edited 03-05-2001).]