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Re: A axis isn't working
« Reply #10 on: October 08, 2013, 05:26:21 PM »
Yes - the drive motor is connected to the a-axis shaft via two timing belt pulleys and a XL belt. Both are 15-tooth at .2 pitch. That would mean the distance of travel for one revolution of the motor would be 3 inches.
Re: A axis isn't working
« Reply #11 on: October 08, 2013, 05:50:14 PM »
"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."


On the General Config. Page - A Axis is Angular.  Top left of page.
John Champlain

Offline Fastest1

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A axis isn't working
« Reply #12 on: October 08, 2013, 06:58:14 PM »
Yes - the drive motor is connected to the a-axis shaft via two timing belt pulleys and a XL belt. Both are 15-tooth at .2 pitch. That would mean the distance of travel for one revolution of the motor would be 3 inches.
How can you translate degrees into linear distance? If both pulleys are 15 tooth there is no gearing. It should be microstepping value 1/8 the you said. 200x8=1600 steps per revolution of the stepper. Is there a picture of this set up? The actual A axis?
I want to die in my sleep like my grandfather, not like the passengers in the car! :-)

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Re: A axis isn't working
« Reply #13 on: October 08, 2013, 07:11:33 PM »
Does it have a worm gear?
I want to die in my sleep like my grandfather, not like the passengers in the car! :-)
Re: A axis isn't working
« Reply #14 on: October 08, 2013, 10:46:20 PM »
Thanks for the replies.

Here is a pic of the '4th-axis'.

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A axis isn't working
« Reply #15 on: October 08, 2013, 11:04:57 PM »
Ok no mechanical advantage or reduction. I was just verifying as the problems seem odd.
I want to die in my sleep like my grandfather, not like the passengers in the car! :-)

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Re: A axis isn't working
« Reply #16 on: October 09, 2013, 02:25:14 AM »
As Fasttest1 stated:
“200x8=1600 steps per revolution of the stepper.”
Note the units are steps per revolution
I think what you are wanting is actually steps per degree.
So divide the 1600 steps per rev by 360 to get 4.4444 steps per deg.
al
 
Re: A axis isn't working
« Reply #17 on: October 09, 2013, 11:20:35 AM »
Hi, Thanks for the reply.

I have used the 4.444 step per setting but the movement of the a-axis was virtually imperceptible, although I was able to hear a tick-tick-tick-... which was likely each degree. The velocity line was not visible on the motor tuning graph, probably below the range. Nonetheless, maybe I can jack up the Acceleration to compensate.

Thanks again for your help.

Offline Hood

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Re: A axis isn't working
« Reply #18 on: October 09, 2013, 11:31:57 AM »
Can you attach your xml please
Hood

Offline alenz

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Re: A axis isn't working
« Reply #19 on: October 09, 2013, 02:23:05 PM »

Looks like your Steps per Degree is resolved and you have now run into a feedrate issue.

Here again the problem is the different units. As an example say you have a feedrate of F10. A feedrate of 10 in/min would be quite reasonable for the linear axis but 10 deg/min for the A axis would barely go tick, tick, In fact it would take over half an hour to go only one rev. To obtain say 10 RPM on the A axis would require an F3600.

If your project will allow keeping the linear and rotary moves on separate lines, then enter the desired feed on the line for each axis.  Make sure your A axis velocity is set high enough.

If not, it gets a little trickier. Mach has a feature called ‘Rotation Radius’ on the Settings page. This will allow Mach to calculate internally a deg/min that will result in the requested linear feed at a given radius. 

You may find this calculator helpful:

http://www.machsupport.com/forum/index.php/topic,16315.0.html

Hope this helps.
Al

Hi, Thanks for the reply.

I have used the 4.444 step per setting but the movement of the a-axis was virtually imperceptible, although I was able to hear a tick-tick-tick-... which was likely each degree. The velocity line was not visible on the motor tuning graph, probably below the range. Nonetheless, maybe I can jack up the Acceleration to compensate.

Thanks again for your help.