Hi Keith - shell is probably the weakest function in MoI currently, it's a very complex operation since any surfaces that do not meet up smoothly will not have offsets that exactly meet up and they will need to be extended and intersected with each other. The geometry library that MoI uses doesn't have a very good mechanism for that. It can work for simple cases but with 392 faces in your model that's a lot of extensions and intersections to be calculated. Then on top of that you've got some small sized features and surfaces with tight bends in them and if your shell offset distance is larger than the size of those small feature that's an additional difficulty.

You might try bringing it into something like OnShape which has a much more sophisticated shell function, but it's probably going to be difficult to shell anywhere.

You could probably make some progress on building a shell by using Edit > Separate to break some of the large surfaces out to individual surfaces and then use offset on those surfaces to build some pieces and then work on filling in the gaps.

- Michael

Hi Michael
Thanks for the explanation. I was just curious and you have explained very clearly.
Keith

Wow, Keith that looks super impressive! I haven't modeled anything like this before so it's cool to see someone do it. Also thank you so much for the YouTube link

Hi Kuro
Thank you and you're welcome. It's a shame it doesnt shell very well for the purposes of 3d printing which is what Marv was trying to achieve. Of course with moi there will be a better way of making the same thing.
Keith

Here is a way to work out complex shells.

I take Keith's Radial file, then de-feature and shell the base shape. Then I can join the shelled result onto the top detail:



This is leaving the detail at a larger depth. If that little extra material "Just had to be removed", I would handle this by keeping the original "Spoke" pieces as they were before the Boolean. Most likely these can be shelled as separate objects. They can then, at this stage, be Boolean cut from the underside, to create that part of the shell.

The depth of my shell was a bit greater than was mentioned (.03125). I would have had to remove the cuts between the spokes, then recut them after, because they are deeper than that.

Anyway, hope that helps for this.

Hi There

The zipped file above is printable but does need some fixing by my slicing program. Thats Keiths file

I printed it at .65 x size at 35 micron layer on my Kevvox

there is good detail in the top although the sharp edge on the centre hole peeled away from the centre slightly

I get better prints if the parts are not joined but intersect each other. unless you need fillets on the joined parts




cheers
shayne

Now I look inside Keiths model there are some strange parts that do not make it easy to slice

removing some of the surfaces here is whats inside

perhaps thats why he had problems shelling it or the result of an attempted shell



cheers
shayne

Radial solid "Good good".....

Hey shayne
Good to see my model made real, I have never seen that before.
Regards
Keith

Hi BurrMan
I didnt know you could Join object like that, so thanks for the video. I did do this which seems simpler but no way could I shell the whole thing. I even tried onshape as advised by Michael. It must sometimes be really frustrating to do this sort of thing for a living and to a deadline.

https://www.youtube.com/watch?v=Xwi6SkZ9r5Y