more 4th axis stuff

[Zbuilder]

I have my datum Work Plane (Top) as the center of the rotary table (C axis). I select a curving chain which lies on a flat plane (2d). "Rotary Axis" is enabled with "Rotary Axis Positioning". When I use the Mastercam 4 axis VMC post, there is no rotary positioning, but the backplotting shows rotary motion. When I select "3 Axis" under Rotary Axis, it also shows on screen does post rotary positioning but I get an error which reads, "Error - More Than 1 Rotary Axis Detected In Selected Axis Combination - Output May Be Invalid". The C axis is set up as a Nutating axis rotating about the A axis but not needed for this job.

[Piglet Trespassers William]

Ditto

mEANS THAT AT LEAST YOUR AXIS DIRECTIONS WRONG

Make Gview=cplane to see what I mean

[Piglet Trespassers William]

That means that according to your toolpath and planes you need more than one rotary axes .

easy to get this sort of things if you

mess with direction of axes

MC knows you have four axes availible ,not 5 ,so you get error message

[Zbuilder]

I don't understand why it would need a 5th axis. Only Z, X & C are needed.

[Piglet Trespassers William]

You don`t ,but mastercam think you need it !

I had this error bunch of times ,and every time

the program was right ,and I was wrong !

If you cool yourself and just look on your toolpath through the mill you`ll see that one of directions or sides is wrong

So like you kinda start your 4 axes stuff and in one of your operations one of your axes is in opposite directions ,and to make it MC needs to turn it 180 degrees and that is second rotary and you get error

[Zbuilder]

looking thru the backplotting, the C axis always rotates in the same CCW direction. It never reverses direction. The X Axis is moving + & -, the Z axis never moves once it plunges into the part & the Y axis seems to be staying on the centerline. I can't really tell because the X Y Z positions don't really match what's going on; must be because the Rotary Axis is enabled.

[Piglet Trespassers William]

I can't really tell because the X Y Z positions don't really match

~~~~~~~~~~~~~~~~

That`s it

[Zbuilder]

Well, it matches the actual X Y Z moves without the rotary axis enabled but with Rotary enabled, the back plotting doesn't convert the position display for rotating. bummer.

[Don S at Barefoot CNC South]

Zbuilder can you put it on the FTP site?

[Paul Decelles]

The error message "Error - More Than 1 Rotary Axis Detected In Selected Axis Combination - Output May Be Invalid" is telling you that the post only supports 4 axis (3 linear and 1 rotary) and the currently selected axis combination has 2 (or more) rotary axis in it. So, the post is basing it's rotary settings on the last rotary axis encountered in the axis combo 'tree'.

 

This is obviously a problem if you are rotating about the 'X' axis and the last rotary encountered is rotating about the 'Y' or 'Z' axis (and will result in no rotary motion output to the .nc file in most cases).

 

Try deleting the rotary axis that you do not need from the axis combination and see if that helps.

[Zbuilder]

OK I'll try deleting the A (Nutating) axis. BTW, the rotary axis is rotating about the Z.

Thanks

[Zbuilder]

OK, it worked when I got rid of the tilt axis on the rotary table. I did not get the error. This is when the Rotation Type is set to "3 Axis". Shouldn't it output the C axis when set to "Rotary Axis Positioning" ?