Centroid Community CNC Support Forum

Some time passed to setup the cabinet... progress:


Tested Y axis and it works fine.

Remaining some stuff for limit switches, Z axis setup and refining some items in the cabinet.

I have a question related to optimum steps/revolution.

Default setup is 1600 steps/revolution, and possibilities are as attached doc below.

What do you think is optimum ratio, and what is the logic for the calculation ?

Many thanks !!

Run that or 2000 see how it goes...

You can calculate how much movement a step will result in. There's no point ending up with a very small resolution that your machine can't possibly deliver due to backlash and nonlinearity. If you have a direct drive 5mm ballscrew and 5000 steps per rev, each step would be equivalent to 0.001mm (1 micron). There are no machines on this site that could come close to that, so going even higher resolution would be pointless. 1600 would give around 0.03mm or 1 thou per step, which might be achievable. You'd have to check my sums.

The other consideration is the max pulse frequency of the Acorn. If you were to set that to the lowest setting of 100kHz, 5000 steps per rev would limit you to a max speed of 20Hz or 1200rpm or 100mm/s or 6000mm/min. That might be sufficient unless you want to brag on Youtube. If the ballscrews can handle it, the servo(?) motor presumably can run nearer 3000rpm. If you can use the highest 400kHz setting, there's no practical limitation - you could run silly 5000 steps / 1um resolution and run the motor at its max speed.

Thanks for the explanation.

This seem to progress...

Home setting OK:

https://www.youtube.com/watch?v=iRxLMn9qFS8

I want to check repeatibility of homing. in some quick visual checks using mill's axle dial indicator seem it is quite good. Will check with a gage.

Wabeco spindle in control:

https://www.youtube.com/watch?v=wi_DC57aZOM

Now it's time to make the final routing of steppers control cables. Plan to route encoder's as much far as reasonable possible from power cables.

Hi,

What is the logic to select pulse frequency from options 100, 200, 400 ?
I have done some numbers and would like to try:
- 200 Hz pulse rate
- 6400 steps/rev

Is there any restriction due to having 4 axis in my system ?

I could directly try BUT a first check is also good.

Thanks very much.

It's Drive specs. Repost the drive manual. Look for max step frequency

Hi Marty,
Max. drive frequency is 200 KHz.
Attached drive specs (model CL86T)
Thanks for the help.

LorenzoRR wrote: ↑Tue Aug 25, 2020 10:19 am Hi Marty,
Max. drive frequency is 200 KHz.
Attached drive specs (model CL86T)
Thanks for the help.
41-Stepperonline-Controlador-CL86T.pdf

Then that is your max frequency the drive can handle. Leave it at 200khz for reliable operation.

Marty