Chiaphua in reverse??

[Christina]

Alright guys, I have a question (my first question ever in the technical help forum ). When you run a drill motor in reverse, I know you lose about 15% (aka the brushes are at about a 15º incline) in efficency. So, I was curious, does anyone know if the chiaphua motors have that kind of loss in efficency if run in reverse? Hmm...I hope that makes sense.

~Christina ºoº

[Bill Whitley]

I was under the impression that the drill motor ran at approximately the same speed in both forward and reverse.

Can anybody out there who really knows the motors confirm/refute this?

Bill

[Joe Johnson]

There is a big debate about this issue.

People I trust are on both sides.

On the drills there is some asymmetery in the brush mountings. This does cause some variation from CW to CCW.

The debate is about the amount of difference it makes. I have seen REAL DATA at 12V that suggests that there are not that big of differences between the 2.

I have also been told that the effect is more pronounced at the ends of the speed torque curve (at high speeds or high torques) AND that the effect is more pronounced at low PWM values.

I don't know.

If I can, I put the motors rotating in the same direction. If I cannot, I don't.

As to asymmetry in the Chiaphua's. I think that the brushes are symmetric, but I am not going to risk taking the motors apart to find out (by the way, if you do, don't take the armature out of the magnets -- again I have REAL DATA to show that you can lose as much as 10% of the output of the motor by simply taking the armature out of the housing and putting it back in again -- it is a magnitism thing I have been told).

Joe J.