Hello to all!

[amonfort]

Hello everyone,

I wanted to introduce myself and see if I could get any advice on a minor issue. I'm new to the whole world of CNC and am coming across some minor annoyances and headaches.

I recently purchased a small CNC (zen toolworks) maching and have been battling to the death with it. Not that I think they're a bad machine, but there is room for a little improvement (imo) and definitely needs better documentation.

I finally have the machine up and running and after 2 days of trying to figure out tool lengths & offsets, I was finally ready to do my first multi-tool engraving.
Unfortunately something strange happened. Just as I was preparing everything to start, I noticed that the coordinates where no longer matching up to the machine.

Without any G-Code loaded, I would jog the spindle and while the coordinates says I moved a whole 10 inches, I have only moved a fraction of that. I doubled checked and I was using inches, not mm... I even tried switching to mm, and came across the same issue.

Does anyone have any Idea what could be causing this? I verified the "steps per" in motor tuning and they're what zen toolworks says it needs to be.

Any help or suggestions would be greatly appreciated.

Thank you!
Alex

[ostie01]

Have you restarted Mach after setting mm on inch unit, you must.

Is the scale option selected (Right or X, Y, Z DRO's)

What is the step per unit in the motor tuning.

What kind of drives do you use for the motors, if the step per unit if for 200 step per revolution and the drives are in micro/step, that could happen.

How fast can you jog.

Jeff

[amonfort]

Hey Jeff thanks for taking time to help out.

I'll do my best to answer your questions but keep in mind I am only about a week into mach3. If I don't provide the info you're asking for, please cut me some slack.

Ok, so scaling as far as I can tell is off. Its not flashing and they're all set at 1.0000.
Motor tuning settings are as follows. Steps Per 1280, velocity 350 and acceleration 125. (these are their suggested settings)

The steppers are nema 23's and the control card is from here http://www.cncgeeker.com/index.php?main_page=product_info&cPath=1&products_id=41&zenid=f66bf56c96b095318d07951784da57c9 (provided with the kit).
 
I hope I was able to answer everything you asked.

[Hood]

Can you attach your xml and I will see if I can replicate the problem.
Hood

[ostie01]

When you choose the units which Mach3 will work with, you need to re-start Mach in order to be set.

For the driver, S11, S21 and S31 should determine what step resolution you want.  1, 2, 8 or 16 micro step.

for a standard stepper motor, it take 200 to do a full one turn (360 / 1.8 degree) setting to 1

I found this on a forum

I run mine in inches (I'm old) so equating your settings to mine. Steps would be 32512

Do you know the lead of your screws. Are they metric or inch.


Jeff

 

[ostie01]

If I understand, your screw has a pitch of 1.25mm and you're setup in inch.

Your probably in 16 microsteps

so 1.25mm/1inch=  1.25/25.4 = 0.0492125 per turn

3200(200X16 microsteps) / 0.0492125 = 65024 step per unit

Try that

Jeff

[ostie01]

If you're setup in metric.

Microsteps is at 8

this mean 1600(8 X 200) / 1.25mm = 1280 pulses per units.


Jeff

[amonfort]

Yep! you got it sir.

Sorry I was gone for so long, wife needed me for a while then dinner.

The issue was restarting mach after the unit change, but I still have to tune it for inches. It's running now in MM but I prefer to use inches.
As for the step settings, Its on default with whatever zen has on their pdf, I think its 2 (½ step?)
http://www.zentoolworks.com/files/3AxisTB6560_Instruction.pdf.

I guess I'll try playing with the tuning and hopefully I can get it to run at a half decent speed.

In any case, Thank you Jeff!