[cadcamslawek]

Hi
I just finish my 4th axis.
Now program basic rotation type in MDI:
G0 A1.
And it go 360deg.(one full turn) I expected to rotate 1deg.

My system is:
1. Servo
2. Gecko drives G320
3. Worm gear 40:1
4. US Digital Encoders 500 counts
5. Mach3
6. In Mach3 for step I use 80000
(500*4)*40=80000

I like to set this that way so if I type:
G0 A18. it rotates 18deg. not 18 full turns.
How do I do that? Can be done?
Or this is the way how 4th axis work.

[Greolt]

You need to divide the 8000 by 360 = 22.2222222

Greg

[cadcamslawek]

Thanks Greg

Did you mean?

80000/360=222.22222

Slawek

[Greolt]

Yeah I guess I missed a zero.

In effect you want steps per degree, not steps per revolution.

Mine happens to be 222.222222 also. Stepper motor at 2000 steps per motor rev and 40:1 worm drive reduction.

Greg

[cadcamslawek]

Thanks again Greg

Now can you tell me how did you deal with feed and soft limits?

Slawek,

[Greolt]

Slawek

By feeds I presume you mean velocity and acceleration.

That just needs to be fiddled with till you get a setting that is reliable and you are happy with.

As far a soft limits are concerned, I can't see that you would want to use them on a rotary axis.

What would you set them at? Doing work that requires multiple revs in either direction?

I will just leave soft limits off when using the rotary axis.

I can imagine a case for wanting a home switch on it but I have not thought that far ahead yet.

Greg

[cadcamslawek]

Hi
I did mean to ask federate in nc program. And soft limits can you turn off only for A axis, I did not see this option in Mach3.
I need soft limits for my X, Y and Z (I run machine with out limit switches)

Thanks,
Slawek

[Greolt]

You can't turn soft limits off for only one axis. It is all or nothing.

So what I would do in your case is set the rotary axis to a large number pos and neg.

Eg, Soft Max 10000 and Soft Min -10000

This should stop the rotary axis ever reaching the soft limit.

Greg

[cadcamslawek]

Thank you for help
Slawek

[firefoxik]

Yes, usually G0 A1 means one turn according to my postprocessor for ArtCam - it goes A-0.5 to A0.5 for full turn...

[dwalsh62]

To remove Soft Limits on a rotational axis, set Soft Max. = 0 and Soft Min. = 0 and it will never trip the soft limits for the axis.