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A axis isn't working
« on: October 08, 2013, 11:45:57 AM »
I have added a 4th axis to my machine. Am having no luck getting Mach3 to recognize the A-axis as rotational (or angular) instead of linear. I have searched the forums and thought I found the answer several times but no joy. I have enabled the a-axis, set the a-axis as angular in the config screen, checked the 'x-axis as the axis of rotation' and 'A rotations enabled' in the Rotations dialog in the ToolPath dialog. Nonetheless, the added a-axis just turns and turns up to 360 when the g-code line commands A to 360. I have tried many different numbers in the motor tuning and haven't felt totally comfortable with any of them.

My board is a Xylotex board at 1/8 and a Xylotex 2.5A 269 stepper.

I have screen pics for verification if you need them.

Could someone help with what I am missing or doing wrong.

Thanks for your help.
Re: A axis isn't working
« Reply #1 on: October 08, 2013, 02:14:10 PM »
Here are pics to support the text.

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Re: A axis isn't working
« Reply #2 on: October 08, 2013, 02:18:37 PM »
How do you have your tuning on the A axis? IIRC it is 360 on a rotational axis.
I want to die in my sleep like my grandfather, not like the passengers in the car! :-)
Re: A axis isn't working
« Reply #3 on: October 08, 2013, 02:22:35 PM »
If you type
Code: [Select]
G00 A1. do you get 1 rotation?

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Re: A axis isn't working
« Reply #4 on: October 08, 2013, 02:23:44 PM »
It would require A360 for a full rotation
I want to die in my sleep like my grandfather, not like the passengers in the car! :-)
Re: A axis isn't working
« Reply #5 on: October 08, 2013, 02:26:40 PM »
It should require A360 for full rotation is setup right, but he said "added a-axis just turns and turns up to 360 when the g-code line commands A to 360". I remember seeing a mode where A1 equals a full rotation somewhere. Just wanted to eliminate that as a problem.
Re: A axis isn't working
« Reply #6 on: October 08, 2013, 04:12:44 PM »
Thanks for your replies.

Did the G00 A1 test. With the Steps Per in Motor Tuning set at 1600, the A-Axis turns a full 360. If the Steps Per is set to less than 1600, the revolution is less than 360. I just experimented to arrive at the 1600.

When I do the math for Steps Per, I get 13.333. That is 200 x 8 microsteps x 3 (I am using a 15-tooth .2 XL pulley on both the motor and the a-axis) = 4800 divided by 360 = 13.333. The motor will virtually not respond at this setting. It is invisible on the Motor Tuning graph. That is why I experimented to get up to the 1600 Steps Per.

By the way, the a-axis responds the same whether 'A-Axis is Angular' is checked or un-checked. Which leads me to believe this isn't the right setting to make the a-axis rotary, but then where is the correct place to make this change?

Re: A axis isn't working
« Reply #7 on: October 08, 2013, 04:23:36 PM »
G00 A1 should get you 1 degree, if you are getting 1 rotation something is wrong. Is this what you're getting?

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A axis isn't working
« Reply #8 on: October 08, 2013, 05:13:56 PM »
Is your axis direct drive? Otherwise I would think 200x8 (microstepping)x360 or either 200x8x reduction value.
I want to die in my sleep like my grandfather, not like the passengers in the car! :-)
Re: A axis isn't working
« Reply #9 on: October 08, 2013, 05:22:17 PM »
Thanks for the reply.

No - G00 A1 gets a full 360 revolution. Yes, I agree. It should provide only 1 degree. I used the Automatic Calculation of Steps Per - it gave me back 1600.

I feel strongly that the problem lies with the fact that Mach3 isn't doing anything with the A-Axis is Angular check box. There is no different behavior whether the box is checked or not. I wonder if there is any code behind it??

The manuals make frequent reference to setting A-axis to Rotary but nowhere can I find where that is at. I am using R3 revision of the software, which is relatively new I think. I am wondering if this new version eliminated the A-axis to Rotary setting or put in some place other than the General Configuration page.