[Will_0000]

Hi

I am having a few issues with the direction that the 4th axis rotates in. The same issues happens with the CAM post as well as manual programming a part.

Say I start from X0.0 Y0.0 A10.0
If I program:
G1 A35.0 F200
G1X10.0
G1A10.0

The 4 axis will rotate to 35 degrees going clockwise, the X axis will move 10mm and then the 4 axis will continue to rotate a further 335 degrees clockwise to get to A10.0, I need it to rotate anti clockwise as I don't want the pocket to extend all the way around the part.

If I program A-10.0 Then the 4 axis will rotate anti clockwise but will rotate to an absolute position of 350.0 degress, so over shooting where I want it to stop by 20 degrees.

If programmed in incremental then all works well.
G1
G91
A25.0 F200
G1 X10.0
A-25.0
G90

The program is a simultaneous pocket on the 4 axis.

The control is a Meldas M3 on a Leadwell MCV760

Thanks

Will

[Will_0000]

I have been trying a few other options. The above code can be re written as:
G1 A35.0 F200
G1X10.0
G1A-350.0

This will cause the 4 axis to rotate anticlockwise back to the original position of A10.0 and machine the correct pocket.

Does any one know how I would adjust the solidcam post to take this into account so that when I go clockwise it is +A(position) and when I go anticlockwise it is
-360-(A(position)).

Thanks

[jsclark]

I have posted the exact same problem on here and have got no help from anyone... When I try to mill a part on the left and right sides it post an A90 and A-90. So it rotates the part all the way around to the left side again and does the cuts it should have done. It's like the program is not subtracting from 360 degrees and posting an A270. This completely ruins a part if I try to simultaneous mill and turn. Good Luck and will keep you posted it I find the answer to this!

[MilanTristan]

How can -A350.0 end up at A10.0?? I think it has something to do with machine parameter, maybe. If the controller is smart enough to move to the shortest distance instead of taking the long path...

[Will_0000]

The 4 axis has a an absolute position going clockwise A0 to A360 degrees. If you program +A then it rotates around the clockwise direction to achieve your required position. If your program a -A then it rotates around the anti-clockwise direction A-0 to A-360. So if you program A-60.0 Then it will rotate anti-clockwise to A-60.0, This is A300.0 in absolute positional terms terms.

You can get to the same position going clockwise or anti-clockwise by either writing A300.0 or A-60.0

In this case you want the axis to take the shortest path but how can it tell when you want the shortest path, what if on that occasion you want it to rotate all the way around and not come back on itself.

[Kiwi]

Some controllers have a General parameter setting. Don't know about a Meldas.

[MilanTristan]

i can't think of any reason why someone would want to use the longest path considering optimum toolpath. i also don't see how the rotation could damage a part as you have control on how u want to link the toolpaths, obviously with clearance move. i remember changing a parameter to a mach3 machine last time as both +A and -A giving the same movement, but i am not sure about your machine. since you have tried both -A and +A to be working correctly, then your easiest solution could be the postprocessor.

[MilanTristan]

The gcode looks ok, unless you will tell me that your machine from A90 moving to the next A position (A86.25) will move CW almost full turn as both are positive angles. As what I said earlier, if the controller is smart enough to recognize the shortest distance from A90 to A86.25 then it should automatically rotate CCW, that is the reason why you have step by step move in A-axis from A90 to A-30.

%
O5000 (001154-2)
(4X_DRILL_DRILL_5X1.NC)
(COMPENSATION-WEAR)
(Post Rev 1.0)
(FEB-03-2014-7:44:47PM)
(TOOL 2 - DIA 6.8)
G90 G17 G40 G80 G00 G20
T2 M6()
T2
(4X-Drill-drill-5x1)
S1000 M03
G00 G54 G90 X12.0016 Y0. A90.
G43 H2 Z60.
Z44.45
Z44.45
G98 G81 X12.0016 Y0. Z24.1571 R44.45 F33.
G80
Z60.
A86.25
A82.5
A78.75
A75.
A71.25
A67.5
A63.75
A60.
A56.25
A52.5
A48.75
A45.
A41.25
A37.5
A33.75
A30.
A26.25
A22.5
A18.75
A15.
A11.25
A7.5
A3.75
A0.
A-3.75
A-7.5
A-11.25
A-15.
A-18.75
A-22.5
A-26.25
A-30.
Z43.825
Z43.825
G98 G81 X12.0016 Y0. Z24.157 R43.825 F33.
G80
Z60.
M05
G00 G28 G91 Z0.
G00 G28 G91 Y0.
G90
M30
%

In that case, what you would like to have is from A90 directly move to A-30.

%
O5000 (001154-2)
(4X_DRILL_DRILL_5X1.NC)
(COMPENSATION-WEAR)
(Post Rev 1.0)
(FEB-03-2014-7:44:47PM)
(TOOL 2 - DIA 6.8)
G90 G17 G40 G80 G00 G20
T2 M6()
T2
(4X-Drill-drill-5x1)
S1000 M03
G00 G54 G90 X12.0016 Y0. A90.
G43 H2 Z60.
Z44.45
Z44.45
G98 G81 X12.0016 Y0. Z24.1571 R44.45 F33.
G80
Z60.
A-30.
Z43.825
Z43.825
G98 G81 X12.0016 Y0. Z24.157 R43.825 F33.
G80
Z60.
M05
G00 G28 G91 Z0.
G00 G28 G91 Y0.
G90
M30
%

[Will_0000]

The following code is part of the profile. The first one is what solidcam generates and the second is the same code but where I have adjusted the signs on the A dimension so that it machines correctly.

Original:
X-2.8643 A6.667
X-2.4663 A7.208
X-2.0309 A7.677
X-1.5637 A8.07
X-1.0706 A8.38
X-0.5576 A8.605
X-0.0314 A8.741
X0.5016 A8.786
X11.2916
A16.643
X11.1124 A16.389 (**)
X10.1124 A15.039
X9.6596 A14.499
X9.1671 A14.045
X8.6422 A13.686
X8.0926 A13.425
X7.5263 A13.267
X6.9516 A13.214
X0.5016
X-0.0314 A13.259
X-0.5576 A13.395
X-1.0706 A13.62
X-1.5637 A13.93
X-2.0309 A14.323
X-2.4663 A14.792
X-2.8643 A15.333
X-3.5078 A16.311
A11.
X-3.5248 A10.779
X-3.5747 A10.57
X-3.655 A10.384
X-3.7614 A10.231
X-5.7542 A7.969
X-5.8606 A7.817
X-5.9409 A7.63
X-5.9908 A7.422
X-6.0078 A7.201
A0.792
X-5.9778 A-0.119
X-5.8881 A-1.022
X-5.7396 A-1.906
X-5.5338 A-2.763
X-1.0965 A3.981
X-0.8268 A4.331
X-0.5244 A4.612
X-0.1968 A4.819
X0.1481 A4.944
X0.5016 A4.987
X13.0498


Adjusted:
X-2.8643A6.667
X-2.4663A7.208
X-2.0309A7.677
X-1.5637A8.07
X-1.0706A8.38
X-0.5576A8.605
X-0.0314A8.741
X0.5016A8.786
X11.2916
A16.643
X11.1124A-343.611 (An anti-clockwise move is written from the other side of the 4 axis. 360-16.389(**)=-343.611
X10.1124A-344.961
X9.6596A-345.501
X9.1671A-345.955
X8.6422A-346.314
X8.0926A-346.575
X7.5263A-346.733
X6.9516A-346.786
X0.5016
X-0.0314A13.259
X-0.5576A13.395
X-1.0706A13.62
X-1.5637A13.93
X-2.0309A14.323
X-2.4663A14.792
X-2.8643A15.333
X-3.5078A16.311
A-349.0
X-3.5248A-349.211
X-3.5747A-349.43
X-3.655A-349.616
X-3.7614A-349.769
X-5.7542A-352.031
X-5.8606A-352.183
X-5.9409A-352.37
X-5.9908A-352.578
X-6.0078A-352.799
A-359.208
X-5.9778A-0.119 (The same applies here, this is correct as it is an anti-clockwise move. If it where to be a clockwise move it should be - A359.881)
X-5.8881A-1.022
X-5.7396A-1.906
X-5.5338A-2.763
X-1.0965A3.981
X-0.8268A4.331
X-0.5244A4.612
X-0.1968A4.819
X0.1481A4.944
X0.5016A4.987
X13.0498

As can be seen any move that requires it rotate in the opposite direction to what it's last move was the A direction needs to be rewritten.

[jsclark]

Ok, if I have a pocket on all 4 sides of a Square, my gcode should have A0, A90, A180, and A270.. Instead, I get A0, A-90, A180 and A90. So the outcome is a part that is milled on 3 sides unless I manually change the code every time.

[MilanTristan]

Ok, if I have a pocket on all 4 sides of a Square, my gcode should have A0, A90, A180, and A270.. Instead, I get A0, A-90, A180 and A90. So the outcome is a part that is milled on 3 sides unless I manually change the code every time.

what is the difference between A-90 and A270??

[Will_0000]

Interesting

On my machine that would work fine, I would get the four sides machined it would just do it in a funny order. A you say is should say A0.0, A90.0, A180.0 and A270.0

If I ran your code on my machine:

1)I would get a pocket at A0.0
2)It would then rotate 90 degrees anticlockwise to A-90.0 (which is an absolute position of A270.0, passing through an absolute position of A0.0)
3)It would then rotate 270 degrees clockwise to A180.0 (passing back through an absolute position of A0.0)
4)It would then rotate a firther 270 degrees clockwise to A90.0 (passing through an absolute position of A0.0)

It looks like on you machine that it take A90.0 and A-90.0 to be the same absolute position where on mine if I program a A- it starts counting from the anti-clockwise direction rather than the clockwise direction.

[Will_0000]

A-90.0 and A270.0 are the same position just taken from different sides of the 4 axis.

[MilanTristan]

A-90.0 and A270.0 are the same position just taken from different sides of the 4 axis.

I understand, that is why I am wondering how he is getting 3 sides only being machined, and which side/angle is not machined?

[MilanTristan]

The following code is part of the profile. The first one is what solidcam generates and the second is the same code but where I have adjusted the signs on the A dimension so that it machines correctly.

Original:
X-2.8643 A6.667
X-2.4663 A7.208
X-2.0309 A7.677
X-1.5637 A8.07
X-1.0706 A8.38
X-0.5576 A8.605
X-0.0314 A8.741
X0.5016 A8.786
X11.2916
A16.643
X11.1124 A16.389 (**)
X10.1124 A15.039
X9.6596 A14.499
X9.1671 A14.045
X8.6422 A13.686
X8.0926 A13.425
X7.5263 A13.267
X6.9516 A13.214
X0.5016
X-0.0314 A13.259
X-0.5576 A13.395
X-1.0706 A13.62
X-1.5637 A13.93
X-2.0309 A14.323
X-2.4663 A14.792
X-2.8643 A15.333
X-3.5078 A16.311
A11.
X-3.5248 A10.779
X-3.5747 A10.57
X-3.655 A10.384
X-3.7614 A10.231
X-5.7542 A7.969
X-5.8606 A7.817
X-5.9409 A7.63
X-5.9908 A7.422
X-6.0078 A7.201
A0.792
X-5.9778 A-0.119
X-5.8881 A-1.022
X-5.7396 A-1.906
X-5.5338 A-2.763
X-1.0965 A3.981
X-0.8268 A4.331
X-0.5244 A4.612
X-0.1968 A4.819
X0.1481 A4.944
X0.5016 A4.987
X13.0498


Adjusted:
X-2.8643A6.667
X-2.4663A7.208
X-2.0309A7.677
X-1.5637A8.07
X-1.0706A8.38
X-0.5576A8.605
X-0.0314A8.741
X0.5016A8.786
X11.2916
A16.643
X11.1124A-343.611 (An anti-clockwise move is written from the other side of the 4 axis. 360-16.389(**)=-343.611
X10.1124A-344.961
X9.6596A-345.501
X9.1671A-345.955
X8.6422A-346.314
X8.0926A-346.575
X7.5263A-346.733
X6.9516A-346.786
X0.5016
X-0.0314A13.259
X-0.5576A13.395
X-1.0706A13.62
X-1.5637A13.93
X-2.0309A14.323
X-2.4663A14.792
X-2.8643A15.333
X-3.5078A16.311
A-349.0
X-3.5248A-349.211
X-3.5747A-349.43
X-3.655A-349.616
X-3.7614A-349.769
X-5.7542A-352.031
X-5.8606A-352.183
X-5.9409A-352.37
X-5.9908A-352.578
X-6.0078A-352.799
A-359.208
X-5.9778A-0.119 (The same applies here, this is correct as it is an anti-clockwise move. If it where to be a clockwise move it should be - A359.881)
X-5.8881A-1.022
X-5.7396A-1.906
X-5.5338A-2.763
X-1.0965A3.981
X-0.8268A4.331
X-0.5244A4.612
X-0.1968A4.819
X0.1481A4.944
X0.5016A4.987
X13.0498

As can be seen any move that requires it rotate in the opposite direction to what it's last move was the A direction needs to be rewritten.

hey Will, I wonder how your machine would react to angles like A10, A370, A730 or A-5, A-365, A-725? will it stay or will it rotate??

[Will_0000]

hey Will, I wonder how your machine would react to angles like A10, A370, A730 or A-5, A-365, A-725? will it stay or will it rotate??

If I program:
G1 A10.0 F1000
G1 A370.0
G1 A730.0

It rotates to A10.0
It then rotates a full 360 degrees clockwise to finish at A10.0
It then rotates another full 360 degrees clockwise to finish at A10.0

If I program
G91
G1 A730.0 F1000

It rotates 2 complete revolutions and then a further 10 degrees to end at an absolute machine position of A10.0

[MilanTristan]

If I program:
G1 A10.0 F1000
G1 A370.0
G1 A730.0

It rotates to A10.0
It then rotates a full 360 degrees clockwise to finish at A10.0
It then rotates another full 360 degrees clockwise to finish at A10.0

If I program
G91
G1 A730.0 F1000

It rotates 2 complete revolutions and then a further 10 degrees to end at an absolute machine position of A10.0

how would the machine behave is case like this?

A-345.
A-348.75
A-352.5 (CCW)
A-356.25 (CCW)
A0. (CW or CCW because of + angle??? does this need to be A-0???)
A-3.75 (CCW)
A-7.5 (CCW)

[Will_0000]

how would the machine behave is case like this?

A-345.
A-348.75
A-352.5 (CCW)
A-356.25 (CCW)
A0. (CW or CCW because of + angle??? does this need to be A-0???)
A-3.75 (CCW)
A-7.5 (CCW)

If I program it as above:

G90 G40 G17
G0 G54 A0.0
G1 A-345 F2000
G1 A-348.75
G1 A-352.5
G1 A-356.25 (The 4 axis rotates CCW up to this point)
G1 A0.0 (The 4 axis rotates 356.25 CW to finish at A0.0 the same applies for A-0.0)
G1 A-3.75 (The 4 axis rotates 3.75 CCW)
G1 A-7.5 (The 4 axis rotates a further 3.75 CCW)




In a CCW move to continue to A0.0 it needs to be written as A-360.0 as shown below which works correctly.

G90 G40 G17
G0 G54 A0.0
G1 A-345 F2000
G1 A-348.75
G1 A-352.5
G1 A-356.25
G1 A-360.0
G1 A-3.75
G1 A-7.5 (The 4 axis rotates in a continuous CCW move up to this point)

[imachining-6061]

Guys it should be setting problem in the 4 th axis controller . Set your maximum 4 th axis rotation to 180 degrees it will prevent your 4 th axis rotating all the way around to 360 deg . The maximum limits will be 180 to -180

[Will_0000]

Guys it should be setting problem in the 4 th axis controller . Set your maximum 4 th axis rotation to 180 degrees it will prevent your 4 th axis rotating all the way around to 360 deg . The maximum limits will be 180 to -180

Thanks, Shown is the axis parameter page. If I follow you correctly you are saying set options 14 and 15 to 180 and -180 respectivly?