Hi Alex,
try boolean inner from outer rather than shell.
Cheers
Barry

Or another way is sweep the outer circle with "Cap ends" turned off, sweep inner circle also with "Cap ends" off then make end caps by selecting inner and outer circle together and use the Construct > Planar command, then select the 2 sweeps and 2 end caps and use Edit > Join to glue them together.

- Michael

Hi all.
I ran into this problem: the "shell" command does not process all values, in this case from 0 to 1, and then 3 and 5 and some intermediate values.
Maybe it's just me?
Moi v5 beta nov 29 2023

Hi WN, currently shell in MOI is just not very reliable, it should get a big boost though once I switch it to be handled by ACIS.

- Michael

Hi Michael, I see now, thanks.
There is another problem there, perhaps it is also related to this command, the display of surfaces and bodies disappears.
But if you apply the "separate" command, then visibility is restored.
The file is the same.

Hi WN, the surface visibility problem was a bug in the Nov-29-2023 v5 beta, it should be fixed in the Dec-1-2023 v5 beta so please update to that version: https://moi3d.com/beta.htm .

Thanks, - Michael

Thanks all for the workarounds - I have been converting a few of these type of curves in preparation for bending most shell fine in MOI. Have read the above comments - I am trying to work out what causes the geometry from not working I checked direction in Rhino and the PIPE command in Rhino also and the same curve came up fine. Any ideas welcome.

Hi Alex,

re:
> I am trying to work out what causes the geometry from not working

Do you mean not working for Shell? Or something else?

- Michael

Hi Michael,

Thanks for reply YEP the shelling try to work out why MOI is having problems shelling without a manual construction of the shape.

regards
Alex.

Hi Alex, shelling is probably thinking that some of the edges are sharp and that they need to be extended and intersected which it does not do a good job of.

This should get a lot better when I'm able to get shelling handled by ACIS but for now you would need to generate the shelling manually as described above.

Do you need more details on how to do that part?

- Michael

Thanks Michael that probably makes sense - the work around also and have rhino and solidworks as backups so all good for the moment. So far in the files I have been generating in MOI have been shelling AOK its the first one that failed will put some of the files through the tube bending software and see how they behave will post real world transitions of some of these shapes as they happen.

regards
Alex.

Hi,
There seems an issue with the curve as when you sweep the circle it produces 2 objects not 1.
This corresponds to a end point on the curve.
Removing this point allows the sweep to generate a single object as it should.
Cheers
Barry

Hi Barry.
The problem is that there is no tangent between them.
This can be fixed roughly by running the "union" command or by deleting one of the segments, then use the "sweep" command to connect the ends, after applying the "separate" command to the curve. Or make the arcs tangent.
You cannot delete a point, because you will get a nurbs curve, and here you need lines and arcs. Everything else, that is, all kinds of splines, nurbs curves, and so on, are not suitable for this. Most CNC machine control racks allow you to import DXF files, but they should contain only lines and arcs, since initially the structure of the control program is the movement of machine organs along straight lines, which are G1 X...Y...Z... and arcs G2 X...Y...Z... i...j...k... and G3 are the same but in a different direction.

HI Barry, I have broken the curve down to smaller arc segments to try to identify the problem area do you mind taking a screen shot of the problem end point.
Many thanks Alex.

Hi Alex,
attached drawing shows the point.
However taking WN post into consideration this converts that section into a nurbs curve not a arc.
Cheers
Barry

Many thanks for the highlight will go over the construction of this curve set another time and see if I get a clean build.
Much appreciated.
regards
Alex.