Cutter Comp Problem on VF0

[Fairlane6t9]

Hi all....I have a slight problem with cutter comp. I have a program to cut one straight line by turning cc on at 90 deg to the part using a .5 end mill (Tool 1). It takes 3 passes, but on the 1st 2 passes, y stops short of it's intended value (stops at 1.2226). Pass 3 goes where it's supposed to. Here's the snippet of code. If I take out the geometry value in tool 1's registry, y will go to it's intended value on every pass, but x is obviously too far over. What am I doing wrong?

G17 G20 G40 G49 G80 G90
T1 M06
G54 G00 X-1.0 Y-1.0 S2292 M03
G00 G43 H01 Z.5 M08
G01 Z-.09 F27.
G01 G41 D01 X0.0 Y-1.0
G01 X0.0 Y3.5
G01 Z2.0
G01 X-1.0 Y-1.0
G01 Z-.18
G01 X0.0 Y-1.0
G01 X0.0 Y3.5
G01 Z2.0
G01 X-1.0 Y-1.0
G01 Z-.27
G01 X0.0 Y-1.0
G01 X0.0 Y3.5
G00Z2.0 M09
G01 G40 X-1.0 Y3.5
M30

[anemachinebc]

i would only use comp in an x y move and turn it off before you do your z. Then turn it back on when you do your x y move. Give it some room to turn on and off usually 1/2 of what you have in your comp screen.

If you use comp and start doing z moves and rapid to a different section it screws it up.

[beege]

Try turning off your comp when done with the cutting, each and every time, otherwise, it will comp every line and arc, whether you want it to or not.

G17 G20 G40 G49 G80 G90
T1 M06
G54 G00 X-1.0 Y-1.0 S2292 M03
G00 G43 H01 Z.5 M08
G01 Z-.09 F27.
G01 G41 D01 X0.0 Y-1.0
G01 Y3.5
G01 Z2.0
G01 G40 X-1.0 Y-1.0 (TURN OFF COMP, WILL POSITION AT X-1.0, Y-1.0)
G01 Z-.18
G01 G41 X0.0 Y-1.0 (TURN ON COMP AGAIN)
G01 Y3.5
G01 Z2.0
G01 G40 X-1.0 Y-1.0 (TURN OFF AGAIN)
G01 Z-.27
G01 G41 X0.0 Y-1.0 (TURN ON AGAIN
G01 Y3.5
G00 Z2.0 M09
G01 G40 X-1.0 Y3.5
M30

[mactec54]

Hi Fairlane6/9

What do you need cutter comp on for in the first 2 passes you should only need it for the last pass for any final ajustments to/for the cut part

[beege]

Originally Posted by mactec54 Hi Fairlane6/9 What do you need cutter comp on for in the first 2 passes? You should only need it for the last pass for any final adjustments to/for the cut part

Looks as though these are depth cuts, hitting the same compensated wall each time at a different Z. We all have our programming quirks...

[little bubba]

It has nothing to do with the Z moves, but it does have everything to do with not turning off comp at the end of the intended line, which then leads you back to Z moves.

Its trying to comp a 3 point triangle.

X 0, Y -1 to
X 0, Y 3.5 to
X -1, Y-1

The corner at X0 Y3.5 is a tight corner and the cutter can't fit in there.

I would also bet when the cutter comes back for the second pass that you aren't at -1,-1.

As has been said, you need to turn the comp off at the end of each cut, which would require a lead out, a simple G40X-1. before you retract will work.

The code is doing exactly what you are telling it to do(cut the inside of a triangle), unfortunately these things aren't mind readers. Fortunately, its an easy fix and hopefully you didn't crash anything.

[Geof]

I have had similar issues and what I figured out was the controller is looking ahead for the next X,Y move(s) following a Z motion and positions the tool correctly for that move depending on the next move this means if you a programming to stop at a corner it will overshoot or undershoot.

I was programming a profile and raising Z to lift the tool over clamps; everything went okay for clamps that were on a straight side but when the clamp overlapped a corner it would overshoot into the clamp.

The way I worked around it was to always make sure that the X,Y motion following the Z motion was in the same straight line as before for slightly more than a tool diameter.