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Re: Getting small movements which not supposet to..
« Reply #10 on: May 29, 2013, 05:09:33 AM »
For the DC servo drive I didn't change the value so it still CAM_numerator = 1 , CAM_denominator = 1.

Mach3 Motor Tuning:
X:

Z:

In MDI I typed G00X-10Z0, then watching the X axis travel toward the stock direction by 10mm.
Video:
http://s1204.photobucket.com/user/cncfreakcncfreak/media/BVB25L%20cnc%20conversion/M4V05916_zps171cd6de.mp4.html

I also included a gcode output from Visual turn.
Re: Getting small movements which not supposed to..
« Reply #11 on: May 29, 2013, 12:24:27 PM »
Remember I said the Step per was 33 at the beginning of this post, I realized Mach is causing it, so I re-installed Mach3 just before I uploaded the pictures in the last post.
The Dc servo drives are ok, I think is the software that is causing the problem, could it be the Mach3 post processor in VT?
I will try this tomorrow, open a example file in VT (Visual Turn), the file is in inch, change unit to metric, then scale it up the diameter of the part from 7mm to 50mm:
http://youtu.be/WF1sAixhQMY


Offline Hood

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Re: Getting small movements which not supposet to..
« Reply #12 on: May 29, 2013, 03:55:00 PM »
Ok if your X axis is moving 10mm with a 10mm command then you have Mach in Radius mode so you will need to make sure your CAM is set to radius mode. Personally I prefer Diameter mode.

Your code attached above is in inches, I think you said your machine was set up in metric. If so you would be better trying to get the CAM to use metric.
Hood
Re: Getting small movements which not supposet to..
« Reply #13 on: May 29, 2013, 07:47:59 PM »
Ok if your X axis is moving 10mm with a 10mm command then you have Mach in Radius mode so you will need to make sure your CAM is set to radius mode. Personally I prefer Diameter mode.

Your code attached above is in inches, I think you said your machine was set up in metric. If so you would be better trying to get the CAM to use metric.
Hood

"will need to make sure your CAM is set to radius mode"
mm..ok, will look into that.
Yes I use metric only. I have attached a new Gcode file, would you mind have a look at it see if it is in inch or mm?

thanks,

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Re: Getting small movements which not supposet to..
« Reply #14 on: May 30, 2013, 02:44:17 AM »
That one is metric, you can see that by the G21 at the start, the previous one had G20.


Hood
Re: Getting small movements which not supposet to..
« Reply #15 on: May 30, 2013, 06:11:23 AM »
Ok, I got an reply from Mecsoft:

1. Make sure the scale factor for X coordinate under the Motion tab in your post processor is set =1 to output in radius mode.
2. G20 represents output in inches and G21 for MM. You can change this under the General tab in your post processor.

To edit the Mach3 post processor, select Post Process from the menu bar in VisualTurn and click Post Processor Generator. Select the post from the list and click edit.
Re: Getting small movements which not supposet to..
« Reply #16 on: May 31, 2013, 12:00:22 AM »
Is all tuned and running!!

X axis:


Z axis:




Something else bothers me is that extra bit, funnel shape circled in RED:


Video @ 8:11

video link:
http://youtu.be/RS-47_u-DQ0


Offline Hood

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Re: Getting small movements which not supposet to..
« Reply #17 on: May 31, 2013, 02:46:41 AM »
Couple of things, first regards the shape circled in red. Dont worry about that it is just the way Mach Turn displays the part, it looks at all feed moves and thinks they are within the part. Normally Cam would have  rapids close to the end of the stock (to your designated start point) but looks like yours may be using G1's.

Ok the second thing, yes your spindle does seem a bit slow.

Third, I suggest you programme in feed per rev (G95) rather than feed per minute (G94) It is the normal way to do things on a lathe and it means you will always be feeding at a suitable rate even if you call a slower/faster spindle speed. Normally on my big lathe I will rough at 0.3 to 0.35mm/rev and finish at 0.15 to 0.2mm/rev (depends on nose rad of the tool) My lathe is quite solid and has a hydraulic chuck so the roughing is no problem. On the wee lathe I would likely be roughing at 0.2 to 0.25mm/rev.

Hood
« Last Edit: May 31, 2013, 02:49:59 AM by Hood »
Re: Getting small movements which not supposet to..
« Reply #18 on: May 31, 2013, 11:18:59 AM »
About the G94 G95:



My current setting is as above.

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Re: Getting small movements which not supposet to..
« Reply #19 on: May 31, 2013, 01:09:45 PM »
Thats scary stuff there ;D

Thankfully it seems like your post processor is not putting in the G95 (It should) as if it did you lathe would take off at max rapid and try and do its cutting. What you have above is for every revolution of the spindle the axis will travel 800mm.
 When doing feed per rev it will be a fraction of a mm you want your feed set too,  as I mentioned in my previous post.
Hood