DSP nominal stepper controller pulse speeds

[simonhippo]

Hi there, could anybody tell me the optimum pulse speeds for the DSP controller to the 1-Axis CNC/ Laser Machine Stepping Motor Driver (TB6560) please, as I'm trying to work out the pulley sizes for my machine.

Thanks in advance,
Simon.

[twehr]

Hi there, could anybody tell me the optimum pulse speeds for the DSP controller to the 1-Axis CNC/ Laser Machine Stepping Motor Driver (TB6560) please, as I'm trying to work out the pulley sizes for my machine.

Thanks in advance,
Simon.

I could be wrong (it happens ), but I don't think the pulse speed (frequency) will enter into your gearing calculations. Pulse speed is related to how many signals per second the controller is capable of sending/receiving. The important thing with pulse speed is to not send signals faster than it can accept/process.

All you need is the gear diameters and the steps per revolution, which you set. If this is what you were actually referring to, then 1/8th step is pretty standard. I would start with that.

[baccus61]

Hi Simon,
If you set up your drives with 2:1 or 3:1 ratio then you will be in the right ballpark. The X axis doesn't need to be reduced as long as you have a small pulley like 12 teeth or there abouts.

A lot of people think they can get a squillion meters/feet per second out of these things but in reality it's not so. The laser still needs time to start and stop the laser beam pulse as it moves back and forth. When you set up, set the speed to something not so fast like 100mm/sec or 4 inches/sec then work from there. As you get to familiarize yourself with the set up then you can adjust the speed and velocity etc for your particular needs.

When you set up your software you place a mark on the pulley and one on the slide then turn it 1 full rev and then measure the distance it moved on the slide.
Then divide that amount by the steps of your controller (2000 for a Geckodrive controller in 10 micro steps or 1600 for an 8 micro step controller)
This will give you the pulses for the software to be set up.
so-----
if your laser head moved 47.3mm with 1 turn
divide 2000 (10 micro steps) by 47.3 = 42.28 pulses. Enter this value into your set up.
(I think this is correct....... It's been a while....)

to get everything really spot on use the nudge feature where if you click with the mouse on a right,left,up or down arrow on the screen the laser head will move the amount you have set it up by.
Set the nudge to 100mm to start with then press one of the onscreen keys to go the direction you chose. Measure that and adjust your pulses to get it spot on.
If it is short then increase your pulse amount and vice-versa if it is long.
I'm pretty sure this is right. Slap me if I'm wrong.
Richard.