Rotary Preview is off

[JeffreySgroiDesigns]

If I have a round piece, say 3.50" DIA and I profile a 2.00 DIA along the x axis, basically to end up with a hex piece. The preview is curved. The cuts should have a flat bottom, not a curved. Can anybody explain this?

Thank you!

[Rcnewcomb]

I don't get the same thing you do.

Can you post your file?

Likewise, can you view my file on your system?

[JeffreySgroiDesigns]

Yours is a pocket and should be rounded. If I just take a flat bit and run it horizontally along the X axis without it rotating, there should be a flat bottom in relationship to the round surface.

[Rcnewcomb]

You are correct. This is an edge case where the rotary preview is not accurate since the diameter of the bit (2.5") is approaching the diameter of the blank.

Can you provide some background on what you are trying to do? It's possible that a different approach may be needed, or that VCarve may not be the best choice for your project.

[JeffreySgroiDesigns]

I guess I am just trying to use the rotary feature to create a hex. I am sure I can program it to do just that pretty easily however I would like to see it in the preview.

Thanks!

[Tailmaker]

Since the rotary preview is just a wrap of a flat maching situation, I think you can not do this easily with VcarvePro. You would rather need Aspire to model the hex but than you have to use a ballnose to cut that, taking a lot of time.
Or you just cut a flat pocket and turn the axis by 60 degrees every time.

[IslaWW]

Place 6 vectors in the axial (length) direction and profile, on vector for the length that you need. I have done similar, but not using a rotary job setup a while back. I did a profile move laterally, not axially.

This was done with hand coding, as a test and lesson, but all of this can be done in VCPro:

[gregk]

This is an example of limitation of wrapped rotary. It is important to understand that the simulation is performed with flat material. That means that the cut will have flat bottom in the flat mode, which then will then become curved when flat material is being wrapped.
For the simulation to look correct, the flat simulation would need to use a properly curved tool shape, so it becomes flat when wrapped.

You could get a correct preview in Aspire, but only if you have used vector unwrapper + two rail sweep + 3d machining which is an overkill for simple shape that can be cut with 6 profile cuts.

Gary's solution will of course work and you will be able to machine the piece, however it won't help with the preview issue. Again this is just a limitation of wrapped rotary and it is not an easy one to overcome.

Greg K