Cracking - What would cause it?

First print with new software and firmware update. Any ideas? The crack sure appears to be a real crack, but I can’t imagine forces strong enough to cause this and it happened on both sides of the print. Never seen anything like this. Form 2, new tank and nearly new bottle of gray. 100UM layers.



the disk itself needs more support. there’s a lot of load on that protruding part.

Hmm. I’m having trouble visualizing the forces that would result in this cracking and leave the supports intact and the disc in good shape. I am not questioning you, but not understanding. For what it is worth this is Preform’s automatic orientation and supports, but I did cut the support density to .75. I can upload the model if I can get permission from my customer. That would probably be the best way to communicate this best.



Just add a few supports manually that hit the disk just above the level of, and near to where the protruding part is. I would do that both outboard and inboard of the protrusion. Those very tall supports that were auto-added are just about useless. Might even delete those and replace them with points that are in a cluster of three, so the vertical support becomes a traingulated truss if you know what I mean.

Also, how is the model oriented? is the diameter across the tray such that it’s peeling a wide area at once? e.g. perpendicular to the peel direction and forces? if so, realign it 90 degrees, so the peel happens with a thin leading edge for a longer distance in the direction of the peel. that reduces the forces on the part.

That makes sense, adding clusters of supports. The long dimension of the disc is parallel to the peel axis. Thank you for your help.

This happens when the two chunky parts first get connected by a small patch. The peel forces and support geometry result in the two parts being pulled apart, ripping the small connecting patch. This then repeats every layer. More supports should fix it. In particular, if you place a support or two just before the crack starts on both sides of the crack, those supports will likely connect, holding the two halves together better when they do start to combine.

We of course try to make defaults that prevent this from happening. If you continue to have issues, I’d be interested in seeing the model as a test case.

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Thank you. I will get permission to share the model and then share it with you. It’s such a beautifully formed crack it seemed that it happened after forming, but you are telling me it happened at each layer which makes better sense. Just surprising how good the build and cracks came out.

Yea, it’s hard to believe unless you see it happen (which is hard in anything but clear).

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