Servo Motor Upgrade

[Ben-S]

Couple quick questions about the servo upgrade on an M800; the first one would probably answer all my questions, is there any documentation anywhere? A typical servo motor only has one signal wire so I can't figure out why it needs two aux outputs? Is it actually setup to drive a standard DC motor (hopefully)? Since aux two is used can I use that aux table as well? I want to reference the aux 1 table (which i think controls the actual position) with the aux 2 table so i can effectively add an axis to the control.

Any help would be appreciated

[IJ.]

2 AUX's are needed for forward/backward +- switching.

Info provided by the MoTeC guys when I was setting mine up a few years back>>

as for the servo control. No. If it is a DC servo, Pin outs should be Aux1 (A18) and Aux 2(A1). Under the aux output 1, assign fuction 116. That will automatically use Aux 2 also. The hard part, is setting up the numbers for gain, frequency and motor volts. Hopefully you have that availalbe as that is usually included with the servos when bought at an electronic store.

[Ben-S]

So it seems that this option actually relates to a DC motor controller with feedback (actually what i was hoping for). Most servo's are controlled by a PWM signal that corresponds to different positions and the actual feedback is done within the servo (or so i thought) so only one wire with a low side PWM output would be needed (which you could do without even buying the option).

Hopefully someone from MoTeC can chime in and let me know if I'm correct or crazy.

[IDP]

Correct. It's a DC motor controller.
My understanding of a servo is a DC motor with feedback.

So you use the 2 aux outputs for the DC motor and 1 AV input for the feedback.

[Ben-S]

Great now I just need to figure out if putting numbers in the aux 2 table will cause any issue, I guess trial and error can't hurt for that though.

[IJ.]

I used a Bosch MS TPS on mine for position as the output only needed 90 degrees of rotation, worked very well.

[Ben-S]

The one I bought actually has a built in pot so I'm all set there

[IJ.]

What are you driving with the Servo?

[Ben-S]

A wing, a project I've been wanting to try for a while

[IJ.]

LOL now that was unexpected

I hope you post up some pics with a progress report!