4th Axis Offset

[PrecisionD]

When your 4th axis of rotation (A) does not run through your part zero where can you set that offset distance in Mastercam to get the proper dimensional calculations when rotated?

Brandon

[Superman]

Can you be a little more specific about your set-up on the machine and in mastercam ?

eg. you have a round bar in a 4-jaw chuck that has it's centre-line set xxx higher than the centre-line of the chuck

eg. you have a 3-jaw that doesn't run true

eg a horizontal, with the part not set in the centre of rotation ( oops, forget this one, noticed you said (A) )

[Montabelli]

I'm lazy, so I would just translate your part to where the axis of rotation of the part is on the appropriate axis of mastercam, then regenerate your tool path.

or if you are so inclined, you can always use the wcs system that is forever driving me crazy... maybe

[boro_boy]

Originally Posted by PrecisionD When your 4th axis of rotation (A) does not run through your part zero where can you set that offset distance in Mastercam to get the proper dimensional calculations when rotated? Brandon

Brandon...that is a great question, and one which I'd love one of the resident Mastercam gurus to answer. Say your local XZ0 on the part does not correspond with the center of the rotab, says its offset 1.50in X AND 6.0 IN Z ( on a horizontal 4th axis) . How do you get the post to make the correct compensations when rotating in simultaneous 4th axis mode. The better CAM systems in my experience control the offsetting at the postprocessor level so you have the flexibility to set the part where you like, without having to tranlate all your source program toolpaths.

[cadcam]

Are we talking Axis substation or true forth or 4th indexing?
this all make a diffrence.

[tobyaxis]

Originally Posted by PrecisionD When your 4th axis of rotation (A) does not run through your part zero where can you set that offset distance in Mastercam to get the proper dimensional calculations when rotated? Brandon

Need more information on what your trying to do.

[boro_boy]

Originally Posted by tobyaxis Need more information on what your trying to do.

Well its either 4-axis positioning or simultaneous 4-axis contouring. Does anyones have an answer for either ?

[lovecnc2003]

thanks

[boro_boy]

[QUOTE=boro_boy; Say your local XZ0 on the part does not correspond with the center of the rotab, says its offset 1.50in X AND 6.0 IN Z ( on a horizontal 4th axis) . How do you get the post to make the correct compensations when rotating in simultaneous 4th axis mode. The better CAM systems in my experience control the offsetting at the postprocessor level so you have the flexibility to set the part where you like, without having to translate all your source program toolpaths.[/QUOTE]

Obviously there must be an easy way of handling this situation in Mastercam as it is the best CAM software ever. When the original poster first raised this issue I was hoping for a solution, as I have run into this problem more than a few times. I wrote something in VB to process the NCI file and it works, but I would still rather have the post do the work.

[Superman]

The original poster had a situation where he was programming to machine a casting with features on different angles, now each casting has to be re-datumed.

It is possible to alter work zeros by program using maths after setting the first origin
or
The machine may have to be RTPC capable
or
You may be able to utilise a "Fixture Offset Function" ---this may be an option, but check this one out, it may solve basic problems ( I think it uses a CALL OO88 XYZABC structure )