DAKENG u-2 16f84 stepper translator

[vacpress]

Hi gang,

Has anyone tried the pic16f84 stepper driver design from http://www.dakeng.com/u2.html?


does it loose steps? will it run at a reasonable step rate?

i suppose i will cobble together a pic micro programmer and try it out, but i am looking for any information? i would likely run this horror show in half-step mode to run a new piece of art i have been building. eventually i will upload some pictures to show every one..

Thanks!

Robert

[aquasapien]

I have. As stated before I am having some problems but it seems to run fine. I can trace and retrace very well but am having problems getting curves. It only does straight line, but there was a lead from a reply that I need to try out.

I was going to use the boards from CNC robotics book, but had problems with easy access to some components so thought I would try it with a pic. Of course I have been knowen to miss huge parts of the puzzle.

Have a good night.

[Zippi]

Originally Posted by vacpress Hi gang, Has anyone tried the pic16f84 stepper driver design from http://www.dakeng.com/u2.html? does it loose steps? will it run at a reasonable step rate?

I got the PIC program from Dakeng and flashed some 16F84A's on a home-brewed "AN589" flasher (AN589 being the "application note" from Microchip's site). I used some general purpose PNP transistors connected to the gate leads on IRF740 MOSFETs (it's what I had that day) since the 740's aren't logic-level, like an IRL-530 or equivalent. The result is the same at the speeds these steppers can do on a unipolar driver.

The controller itself doesn't lose steps, and will run at step rates a lot higher than a motor can take. The speed of the motors will be slow because of the way they run with this TYPE of this design, all "unipolar" stepper drivers will perform about the same. A bipolar chopper driver is as high performance as you can get for a stepper (Geckodrive).

I had this controller on a "super cheap" machine, and was able to do some engraving with it, though painfully slow (20 TPI screws, 60 oz/in steppers). Even with the motor sitting on the table, I couldn't get too many RPM's before it started to stutter. This is the stepper's fault more than the drive, the drive is doing all it was made to do.

It was a good "first endeavor" into CNC, and allowed me to play around a bit.