Servo resolution and Mach settings.

[Kingjamez]

So I'm using gecko 320's with 250 count 4 line encoders. I have thompson .2" pitch ballscrews. When I tell Mach to move the table of my X3 mill, on the first thou of movement it moves about 1/4 thou. On the second thou of commanded movement it moves 1.75 thou so that it is in the correct place. This pattern repeats every 2 thou. Any idea why I'm seeing this behavior?

Next, when I put in the pulses per inch into Mach the correct setting is 8000, however from the specs above it looks to me like 5000 pulses would be correct. I have verified all of the specs above, so why is 8000 correct?


-Jim

[GaryCorlew]

5000 is the correct number

[Kingjamez]

Originally Posted by GaryCorlew 5000 is the correct number

When I have Mach 3 set to 8000, and ask it to go 1 inch, it goes 1 inch. I turned the ball screw by hand 5 turns, got 1 inch. I took apart the encoder and checked the jumper settings: 250. It has 4 wires going to a Gecko 320. What can I say? I'm baffled.

I've cut out parts that all came out the right size too.

[GaryCorlew]

OK as long as it works, I am assuming they are amt encoders, which I also use, I looked at my documentation and if the encoders were held upside down and you looked at the switches, a setting of 400 would look like 250. Thats about the only explanation I can come up with. And needless to say I have been there, done that, got the tee shirt!

[Kingjamez]

Well, that makes sense! Thanks for figuring that out, it was driving me nuts. I must have flipped over the encoder when I was reading the dip switches.

-Jim