This is done with the Nov 21 beta plus Nov 28 NMTLib.dll.

Simply put, unioning the two pieces causes some sort of weird deletion of the larger piece. For the last hour I have tried a variety of things, like changing the size of the smaller thing, moving it around, simplifying the mating faces, and so forth, to no avail.

Please help! My petite crabe de fer wants to be born in the 3D printer, and this is almost my last step.

Hi Yenmonger, thanks for posting the model.

Directionally it all seems to be ok, I think it may be having some difficulty with the coincident surfaces in here.

One thing I noticed is that it looks like it is supposed to be symmetrical, but there are some differences in that problem area from the other side.

On the "good" finished side, there is a pocket in this area:



But on the problem side, there is not the same kind of pocket:



And if I view it from the back side and zoom in:





There is a pretty thin little slivered surface there, that is not likely to be helping things out very much.

If everything is built to a pretty tight tolerance maybe it will be easiest to delete those faces along that side and mirror all the good ones over if they fit properly, I will give that a try here.

- Michael

Hi Yenmonger, one other thing I noticed when doing some mirroring fixup attempts was a couple of other differences like here:





One side has one of those back plates cut out differently, is it important that those are different or is it ok if those are the same and symmetrical?

- Michael

Hi Yenmonger, the quickest fix in this case is to cut the part in half, mirror it, and then Join the pieces - I've attached the .3dm result file as Cannon 39_finished.zip .

Now it's also got exact symmetry, hopefully that is a bonus rather than problem?

Anyway, the model seems to check out and looks to be ready for 3D printing. Let me know if this does not work ok for you.

- Michael

Thanks! The reason for assymmetry was my ham-fisted attempts to simplify certain areas in an attempt to get the union to work.

The restoration of symmetry is most welcome. Many thanks indeed.