Just to clarify, did you use a quad decoder or quad counter, such as the LS7166?

I used the LSI7266 counter chip (2 channels) for encoder input and 2 X Allegro A3959 motor drivers.

The application was a piece of cinema gear requiring precision motion control.

There are two main software modules required:

1) PID position servo loops

2) Trajectory generators (indexers)

It's a massive project to get all this stuff to work correctly, this project took MONTHS to finish, a gnarly beast.

 

It's a massive project to get all this stuff to work correctly, this project took MONTHS to finish, a gnarly beast.

Thanks for your insight on this Sensacell. I suspected as much.

As I indicated to THE_RB, after I read how easy it is by all the armchair programmers on the web who have never done it but can tell you exactly how, I thought I would pose the question. Thanks again.

If anyone else has any real world experience (no opinions, please) doing this, I would love to hear from you.

 

The problem with servos is I haven't found one that will produce 80 in-lb torque in a NEMA-17 frame. If you know of one, I would sure like to hear about it. If you have used a closed-loop brushed DC motor controller that will handle continuous current of 15+amps,

I know you do not want trivial posts, but I just re-read and realized you are looking for 80 In-Lb (not 80in-oz) in a NEMA-17.
I would think this is totally unrealistic, particularly in a DC brushed motor.
I have used many makes of DC motor in the past and have never come across this torque size in this small a frame.
Maybe 80in-oz?
Do you have a particular example you can share?
Max.

 

I don't consider your posts trivial in the least, Max. Trivial posts are the ones I've received on some forums by armchair programmers who can tell you exactly how to do it but have never done it.

The motors I am using are from this manufacturer: http://www.cclmotors.com/page/products_detail.aspx?item=Permanent%20Magnet%20DC%20Motor. I am using a 16,000rpm brushed DC motor coupled with a 52:1 planetary gearbox. At full throttle, it is rated at 60oz-in torque. Coupled with a 52:1 gearbox I get roughly (150in-lb) out of the motor/gearbox. I can't find the link for the gearbox (chinese) at the moment but it is continuous duty rated just north of 75in-lb of torque. We tested it up to 39ft-lb at which point it sheared the shaft. They're pretty rugged.