Custom Supports

I have a client who wants his model printed with the fewest possible parts. This means I have to print complicated geometry with internal supports enabled. Unfortunately there is very little control over where those supports originate from and their thicknesses. Which means later on they are almost impossible to remove without damaging model itself.

I though I’m going to outsmart preform and build my own internal supports and so I went ahead and added very robust but easy to remove couple of symmetrical sets to one critical section. When compared to what software generated automatically my supports seems to be more comprehensively distributed. Yet, as you can see entire upper section and funnel’s top are both highlighted red indicating insufficient support. Confusing because at the same time preform gives me 3 thumbs up…

At least 14 hours to print so I’m not too eager starting it if I’m about to end up with an unusable piece of junk. Rather would love to hear your suggestions first. My suspicion is that I am missing something obvious here…

Many thanks

You can edit the supports to move them, delete them, or create your own. I routinely do this with object that are placed symmetrically on the platform. The object might be evenly aligned with the platform, but Preform rarely places supports symmetrically on the object. So I move them. I want “uniform” defects on objects that are symmetric. You can also change the contact point size of the support to make it smaller or larger. I find that smaller point sizes work fine for smaller objects, and they leave a much smaller dimple.

Custom supports are something you will gain an intuition for over time. I’ve done a lot of projects with my own support structures generated outside PreForm. I recently tried Formware and like how it allows you to really tailor the geometry.

Don’t get too stressed out over a bit of red. The highlights are just a guide, and PreForm doesn’t have perfect precognition.

Since your part looks rather bulky, be sure you have sufficient, decent sized (or smaller, higher density) contacts on the bottom to make sure it doesn’t shift during peels. The big supports you’ve got coming out of the portholes or whatever on the side will help.

I can’t tell if that top wall overhangs the whole deck below, although it looks like the model itself has some columns to aid with support from underneath?

If those are straight overhangs along the X axis and there’s too much distance between touchpoints you may get a bit of arching on the bottom edge, but I usually tend to be over concerned about that.

One thing I noticed is the base of the branching tree structure you made might be a little undersized for the amount of bulk in the tree and cross sectional surface area after it branches. It looks like you have an opportunity to add some lateral bracing to that structure by snaking over and around the side of the deck. It could join with that large PreForm column and you can attach additional supports out there as required to make sure it’s robust:


Good luck with your print!

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Sorry guys for not replying sooner. Project got canceled and eventually it drifted away from me…
Before though I did managed to modify my own supports. You can see them all in red. Not a pretty picture but it might have worked.
Too bad Preform doesn’t offer custom support generation similar to what Chitubox or LyncheeSlicer are capable of.
I’m thinking, next time something like this happens I might actually use one of those slicers. Add custom supports there, export to stl and than finish inside Preform…
I think generating supports in perform it actually got dumber after latest builds.

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