Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: willems on September 14, 2010, 03:28:48 PM
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we are using the same millingmachine under two profiles
the profile 'left' with 0 of X axis left and with limits setting for motor homing on NOT inverted
the 'right' profile with 0 of X axis to the right and X axis motor homing INVERTED
now when using the same G code on the same machine in the two different profiles we become two different results
one profile with the non reversed homing all dimensions are fine and with the reversed homing all circles are ALL 1mm smaller
in the G code G40 is set the two profiles are identical (except homing direction of X axis)
can anyone help in this strange behavior (we use this method to mill at the faces of a board)
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Can you attach both xml's please.
Hood
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here they are
thanks in advance
aw
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Looking at the xml's I dont see a problem although you have Enhanced Pulsing disabled, is there a reason for that?
I presume the DROs are showing correctly so cant think how I can test but you say circles are 1mm smaller, is that both X and Y or are they oval?
Wonder if using G51X-1 at the start of the code and a G50 at the end would be a better way for you to reverse things, would that be possible with the way things are set up?
I will look again at the xmls and see if I can pick up on anything.
Hood
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there is/was no reason to disable enhanced pulsing..
No the circles are real circles no ovals
we tried your G51X-1 method but this is not a good way because we intend to reverse the board and align it to the other symetric side of the machine because we have only one boardside that is referenced
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Ah Ok, I was wondering if that might be the case with the reversal.
Strange how both X and Y are out, is it just on circles or are other dimensions short?
Do the DROs read correctly?
Hood
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Which xml is giving you the issue?
Hood
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About the DRO's, we did not verify yet
YES we have the same problems with a square cut to
it seems more like an unwanted 'cutter radius compensation' because we have always the same faulty distance
in litlle or large figures
is there a way to really force the G40 command?
in attach a test G code we used to define the faulty dim's
thanks in advance
a.willems (belgium at five to midnight )
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The reason I asked which xml has the problems is I notice in one of them there is a tool dia of 0.5 and I am wondering if that could be the issue?
Hood
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the good one with correct dims is the XML file with 'LINKS' in its name
a.willems
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Ok try this xml and see, but be careful and hand near the E-Stop.
Hood
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we do not use a tool of 0.5mm
we use only a tool of 4 mm
to get a drill of (nearly) 4mm we use in autocad (via DXF and lazycam) a circle of 0,5mm
a.willems
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one xml had a tooldia entry and the other didn't. the one that did was the one above so maybe that is your problem, let me know how it works but be ready with the E-Stop just in case.
Might even be worth cutting air on the first run to see if it looks ok.
Hood
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thanks,
file is alreay downloaded
we will try it in a few hours (machine is now running) and we will give you the results.
Can, you say wath you did in the file? so , if good working, we can prevent for the future?
until tomorrow
a.willems
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the one above with 'rechts' in te name was the wrong one
lets wait and see
thank you very much for the help
until tomorrow
a.willems
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All I did was delete the <ToolDia>0.5</ToolDia> entry.
It may not do anything at all but I am unsure why it is in the xml when your other one does not have it.
If you still get problems it may be an idea to clone the good xml from the Mach Loader and then reverse the axis as you have and see if the problem persists.
Hood
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the one above with 'rechts' in te name was the wrong one
lets wait and see
thank you very much for the help
until tomorrow
a.willems
Yes thats why I took out the entry in that one rather than putting it into the other one.
Hood
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good day again hood
we used your file, no problems with the milling, but the incorrect dimensions are still there....
we have the same missing 1mm on all circles of the test file we send you in G code
we will clone the good XML and try again
until later
a.willems
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we cloned the good file and changed te X axis homing direction
and have THE SAME PROBLEM......
the only thing we changed was in homing and limits...
same files, same program, same machine...
can somebody try this on his machine?
thanks in advance
a.willems
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can somebody try this on his machine?
thanks in advance
a.willems
Edited your code a bit (depth and feedrate) and ran your file, reversed the axis and restarted Mach and ran it again, both came out the same size, see pic.
The big circle on the left is deeper as I forgot to edit the depth but otherwise they are identical.
Hood
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good day hood,
there is nothing wrong...nor the machine nor any program
the only change while milling circles after changing X axis is that they are made counterclockwise in stead of clockwise
so with a rather dull milling tool in wood we got incorrect dimensions
we will try to ask lazycam to program the circles counterclockwise to verify (you know is is possible?)
thanks again
a.willems
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Sorry dont use LazyCAM but I am sure you will be able to specify climb or conventional milling.
Glad you found the problem :)
Hood
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what is your best way to go from .DXF files to G code?
'specify climb or conventional milling' ?????
a.willems
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Depends on your budget I suppose, a lot of people use LazyCAM and I believe Rich has written a manual which should be in the user docs part of the forum.
Climb milling is when the cutter is pulling itself in the feed direction, conventional is when the cutter is pushing against the feed direction.
Hood
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Heres a link I got from a quick google search, it shows better than I have explained. http://www.quadrantepp.com/default.aspx?pageid=201
Hood
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many thanks hood
yes the incorrect dimentions came from the same .dxf file but when changing X axis the milling changed from conventional to climb or vice versa
we got a difference of 2x 0.5mm = 1mm in multiplex (wood)
so we have to master the milling direction for critical figures. You know an easy way ????
a.willems