how to calculate motor tunning

[cob]

hello to everyone,
I am having a problem with my sherline on tunning my motors i know you guys have heard this question before. can someone please explain to me how to set the motors on mach 3. here are the specification on what I have.
for my XandYaxis I have 1/4-20 tpi and on my Zaxis I have 3/8-20 tpi. the motors I have for all three axis are (this is what the nameplate says) they are keling motors (kl23h276-308b) can somebody tell me what I should input on the (step per) and also on the (velocity ins per min) .

[vladdy]

ok...here's a start...
your screws are 20 tpi...
motors I didn't lookup spec on, but are 'probably' 200 step/rev , or 1.8 degree
so that 20x200...or 400 steps per inch...maybe
depending on your drive, single step means 400, half step would be 800,

and so on...

should be enough to get you started, anyways...

enjoy..

[hoss2006]

Originally Posted by vladdy ok...here's a start... your screws are 20 tpi... motors I didn't lookup spec on, but are 'probably' 200 step/rev , or 1.8 degree so that 20x200...or 400 steps per inch...maybe depending on your drive, single step means 400, half step would be 800, and so on... should be enough to get you started, anyways... enjoy..

obviously he meant 4000 and 8000 steps.
Try using 100 for velocity at first.
If the motors miss steps, lower that down, if not, raise it up.

[Bluedog]

I have just tuned mine and they seem to be running great. This may be a dumb question, but how can you tell if they are missing steps?
Thanks.

[hoss2006]

They'll make a clicking/grinding sound and won't spin when they lose steps.

[cob]

Originally Posted by hoss2006 obviously he meant 4000 and 8000 steps. Try using 100 for velocity at first. If the motors miss steps, lower that down, if not, raise it up.

can you tell if this sounds right I put the steps at 3500 and the velocity at 10. but it still soulds like it is grinding and if I put it any higher that run even rougher. can there be something else wrong that I need to fix.

[Fifty_ohm]

You didn't mention if your stepper drivers are full step, half step, /10, etc. so I'm assuming full step.

Take the steps per revolution of the stepper motor (typically 200) times the stepper driver stepping (full step=1, half step=2, /10 = 10, etc.)

200*1=200 This is how many pulses are needed to make one revolution.

Then take the pitch of the drive screw. 20 tpi = 1/20 = .05 (this is how far your machine will move with one revolution of the drive screw).

Take the pulses divided by the pitch. 200/.05=4000 This is how many steps it will take to move one inch (or unit as called out in the mach3 motor tuning screen).

As for what to put in the velocity and acceleration that is figured out with trial and error. What I did was take the velocity and acceleration up until I started to lose steps then I backed it down until it didn't lose steps across the entire travel. Then I backed that down to 80% for rapids. It can be a little tedious but be sure to do it to all your axis as they may not be the same due to weight and friction in travel. I hope this answered your question.

-edit- There were no responses when I put mine in. Must have been quite the backlog.

[Monte]

Originally Posted by Bluedog I have just tuned mine and they seem to be running great. This may be a dumb question, but how can you tell if they are missing steps? Thanks.

What hoss said, and at the end of the program you tell the machine to go to 0,0,0 the axis that missed steps won't be at 0.

[cob]

thanks alot FIFTY and everyone else know it does make sence . I think I am better of here asking question here than going to school. by any chance do you guys know if theres any degrees you can achive on this group. (lol)