Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: dfurlano on December 12, 2006, 02:45:47 PM
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Well here I go again. Not sure if I am doing something wrong but I thought i would throw this out there for ppl to look at.
The design says "Carla & Dan" along the top and "10 Years" along the bottom.
I have a file that cuts a design on a .770 diameter tube using the A and X axis. I set up the A rotary Diameter and configured the toolpath with x as the rotary axis. So far so good. I import the gcode and it looks reasonable. The only minor problem that has existed for many revisions is that the image the toolpath displays is wrapped around the axis backwards. But when it cuts it comes out correctly. So ignore that problem.
When I cut the part it came out totally wrong. The "&" was all the way to the left of the text and "CarlaDan" was crowded together as in the quotes.
The "10 Years" was way off center to the top text and jammed together overwriting the "0" and "Y" and the rest of the letters just crowded together.
My first thought was that I was loosing steps. But the letters look very consistent although crowded. If I was loosing steps I thought it would be more exaggerated.
Anyhow here is the gcode if you care to look.
Thanks.
Dan.
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What did you use to generate the code, DXF file?
if so post it here.
Graham.
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And a picture if of the cut if you will.
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The only obvious thing in your code is that you don't have a feed rate set (NO'F')
Graham.
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Yeah I usually add the feed rate but forgot. I take a picture in a bit.
Here is the dxf file.
Thanks.
Dan.
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Ok, I think I figured out a problem. Although I am still not sure if I am causing it.
I added a feed rate of 3 to the file (f3) only once at the beginning. I also have "use diameter for feedrate" selected in the toolpath configuration.
When I rapid the A axis with either a G0 A0 move in the MDI screen or use the A axis button in the MPG window or my shuttle dial I get about 300 as a reading.
When the program is running I get about less then 50 as a reading. About line 486 there is a big G0 A axis move from about 20 degrees to 120 degrees (about). The A axis accelerates so fast - above 1200 - the motor totally loses position.
So my question is why does it go so fast? I tried turning down the tuning but then the motor turns so slow during G1 moves it would take days to run the file. Or maybe I do not have the tuning set correctly? The other option is I turn the "use diameter as feedrate" off but again there is a huge difference in speeds between a G1 and G0 move.
Am I doing something wrong? This was a problem a long time ago but with version 1.84 it ran very smooth with the existing tuning.
?????
Dan.
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G0 is a rapid and G1 is a feed. Are you running in feed rate over ride? I saw somewhere to check this box if you are. (See Pic.) Your axis should move at rapid, what it is tuned to in motor tuning, without skipping steps. It should never go over that even if you have your feed rate over ride set to 300 with a feed rate of 99999. This Queue box being checked is supposed to fix it if that is the case. If your motor is tuned right then try to back off of the feed rate. I hope all of this makes sense and is what you are asking.
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I reverted back to 1.9.014 and everything works fine.
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Did you try the checkbox in 2.0.025? If not, I will run some test just for fun.
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No I did not try the checkbox... to be honest I wasn't sure where it was.
Thanks for all the suggestions.
Dan.
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Hi, Dan
I had the same problem, unless things have been changed you need to set your F speed to a value greater than 100.
The A axis is now controlling your F Speed, On my rotary table the Vel is 2500 acl is 500, I set it to F 1500.
Then you should see the speed up, and adjust it as needed for proper cut speed.
It has to do with the steps being set to Deg and software not taking it into account.
I've posted or sent an Email to Art and Brian on this before.
Hope this Helps, Chip
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Art has been working on this problem and had done something in the last iteration... I will have to get into it and have a look... please if you can post a two or three line program that is not working well on your machine and I will have a look at it.
Thanks
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Hi, Brian
Looks like Ver. .025 fixes it, earlier ver. were very slow.
Feed-Hold, Re-start, doesn't lose Position now ether in Inc. Mode.
Feed-Hold with jog, Re-start, Goes Bez-erk, into orbit, Spindle orientation is sideways also !!
A axis doesn't rotate with X, Y, moves, (In View Screen Display) Though Actual cutting is fine.
Hears a file Tooth3.txt "gear cutting" its a little more than 3 lines but it shows problem.
Settings: x,y,z 40000 steps, 10 vel, acel. 1, A axis 400.2 steps per deg., vel. 2500, acel. 500, A Dir set to .5
Looking Better All The Time.
Thanks, Chip