Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: mhackney on December 29, 2009, 03:55:13 PM
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Ok, I completed installing a CNCFusion kit on my MicroMark (X2) mill. That all went smoothly, electronics working, etc. Then I started configuring Mach3. Worked through the videos (which were great!) and the docs. I do not have home or limit switches on my mill at this time. But, I put machine zero with the X table all the way right, Y table all the way forward, and Z at top.
soft Max Soft Min
X 8.50" 0"
Y 3.90" 0"
Z -8.40" 0'
This all makes sense to me. When I jog, everything moves in the correct directions and I understand the movement. Now for the problem:
I created a little G code to draw a rectangle with a pencil chucked in the mill.
G00 X2
G00 Y1
G00 X0
G00 Y0
I then set the wok coordinates to the middle of my table and set X=Y=Z=0 (pencil touching the paper). When I run the code the table moves towards the + direction (the same direction that the -> arrow key makes it move) for 2". Then, the Y moves. It moves in the direction the ^ up arrow key moves it. But, on the Tool Table display on the Program Run screen, the Y moves up on the display - which is the opposite of what the Y is actually doing. So, I end up with a figure that is flipped in the Y direction.
I've messed with reversing the Y, etc but can't figure this out.
thanks in advance,
Michael
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The Y should go up in the display, think of what the tool is doing rather than the table.
X + is table moving right to left but tool moves left to right in relation to the work
Y+ Is table moving back to front but tool moves front to back in relation to the work
Hood
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I still don't get it. My X+ is table moving right to left (as you say) but Y+ is table moving front to back so tool is moving back to front - that is where the "problem" seems to be. The Mach3 display makes sense for X movements but is backwards for Y movements. At the end of the day, the object being cut is a mirror image on Y. That can't be right.
cheers,
Michael
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OK if I am seeing it right, the display is showing the toolpath go towards the right from X0 to X2, then it heads from Y0 to Y1 and you are seeing it move up the screen, is that what you are seeing? If so then that is correct and you need to reverse your Y axis in Homing and Limits, you have it the wrong way.
Think of the tool in relation to a piece of graph paper fixed to your table, X0Y0 is lower left so table fully right and fully away from you would put the tool over the lower left corner of the paper. Move the table left and the X would increase, move the table towards you and the Y would increase.
Hood
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Yes, X0 to X2 I see the display move from left to right. That makes sense and seems correct to me. Y0 to Y1 actually moves the table from front to back - again moving in the + direction. The table movement makes sense to me. But, the display moves upwards as you state.
The CNCFusion kit I installed on my mill has Y0 with the table moved all the way to the front so + movement moves the table towards the column. I understand your graph paper analogy. But wouldn't putting Y0 back (table back to column) would make a positive movement towards the front and that opposite of how the CNCFusion direction arrows are labeled (engraved) on the Y bearing block. Not that its a big deal but it would seem that there should be a configuration that would allow Y to be all the way forward at 0?
cheers,
Michael
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You need to think of the tool, not the table. If you think of the tool it is moving exactly as the screen is in relation to your graph paper.
The engraving on the bearing blocks relate to the tool direction not the table movement.
Hood
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But that's the thing, it isn't! The tool is going in the opposite direction on the Y axis (opposite to the display but correct in actual movement to the +)
Michael
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Ok I am confused now, lets go back to the graph paper fixed to the table. Table fully right and fully towards the column puts the tool over the lower left corner, ie X0 Y0, are we agreed on that?
Now you move the table to the left which in effect moves the tool to the right on the paper so it is a positive movement in the X axis.
We now move the table towards us, that makes the tool move up the graph paper in a positive direction so Y is moving positive.
Is that all as you are seeing?
Hood
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If you put a pen in the spindle and a piece of paper on the table and do your square see if it makes sense to you the way it is getting drawn.
Hood
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Ok, I am sitting in front of the mill now.
With the table fully right and back, yes, the tool is over the lower left corner.
Yes on the X movement. Table left, tool right (+ direction).
Move the table forward, tool moves up the graph paper. But the display in Mach has the tool moving down.
Also the right arrow causes the tool to move right (towards +) as I think it should. But using the up arrow causes the table to move towards the column, so tool down.
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That's the thing, the drawing is not correct. It is a mirror image in Y. If I draw a triangle with the point UP on the mach display, it gets drawn with the point forward (away from the pillar). Opposite of how I would anticipate it to draw.
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Ok, I see that my Y is configured incorrectly. Not sure what the proper way to reconfigure it is though - still getting my head around this!
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You need to reverse the Y axis in Homing and limits.
It is one of the hardest things to get your head around with a mill but just wait until you get a lathe as well ;D
Hood
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Ok, when I check the Reverse Axis box in the Homing/Limits dialog, the tool path matches what is drawn on screen. Is that it?
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Yes :)
Also your Up arrow button will move the Y Positive on the screen and in the DRO and the table will move towards you.
Hood
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Yes, it does. I think I understand it now, I think.At least what is drawn on the Mach display is what gets drawn when I mount a pencil and the table movements make sense.
thanks a lot for the help!
Cheers,
Michael
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No probs, as I said its one of the hardest things to get your head around and even after using a mill for many years I sometimes still have to stop and think ;D
It is because you see the table move and it seems to be going the wrong way but in reality you need to think of what the tool is doing in relation to your work. If your mill had a fixed table and the column moved it would seem much easier :)
Hood
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Yes, I had built a CNC router table and the tool moved. That was easier! Oddly, I understood the X movement but my mind was reversing the Y!
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There are mills out there that work that way, my pal has a Chiron mill, really nice machine with lightening fast toolchanges, under 1 second if I remember and the bed is fixed and the column moves. Almost got one myself but the headroom in my workshop is too low :(
Hood