Preform supports and customizing


I have been printing on a couple of Form 2s over the past half year with almost 100% success - modeling in ZBrush. I have been printing in standard clear and tough resins… I really got down prepping the files for solid successful prints with both resin materials and in experimenting and figuring all of this out I came to a much larger question. Most of the models we print are figurative or leans more towards animation/toy figurative level clean forms. Spheres, curvilinear shapes, of every kind, which makes our surfaces kind of important to be clean. I have a background in tooling for toy manufacturing and so prepping/sanding/cleaning/tooling is not an issue. Having said that I find when I print a head of a character for instance (solid or shelled) Preform always wants to put the most supports right where there is the most detail VS a large rounded area that could be cleaned up much easier. I am sure it has something to do with the fact that a face with nose/eyelids/lips, etc. are complex surfaces/forms that need extra supports…? Still I would love to find a compromise or middle road. Maybe my nose is a little less crisp, but I have less supports to clean up. I see there is a way to customize supports, but everyone I talk to, says the second you start removing supports or asking for less %, is the second forms stop printing correctly and its almost 100% on this. I would appreciate any feedback from anyone that has messed with custom presets for supports or if there is any more information? For instance… one character head recently printed and gathered a ton of supports all in one area of a cheek (the piece was shelled) so it orientated it on an angle… Where the cluster of supports was located was so dense, that it created surface ripples that rippled out from the cluster of supports which made me think that possibly gravity/time/the amount of supports was causing this surface issue. So much ripples and support connections it would take me hours to tool and clean up. Beyond the supports was beautiful printing like usual from the Form 2. Any ideas/thoughts/suggestions for how to approach supports in preform and is there really any customization there or does Preform really suggest the best possible successful amount of supports needed? Thanks in advance!

The automatic support generation and orientation is not usually going to get you the best results. I always orient the object and place supports manually.
First–it’s important to look at the part and try to find what orientation you can place it so that you will require the least number of supports or that the supports will be on a surface that you can easily sand smooth. For something like a head for example you want to have supports on the neck stump and then angle so that the nose is pointing slightly upward, that way you don’t need any supports on the face and maybe a little bit on the back of the head.
It helps to angle things so that you don’t have to place a lot of supports on a line but rather to start from a small point and have the layers naturally grow bigger.
Another thing to consider is that the surfaces that face upwards will get the best detail, so sometimes it helps to split a part into additional pieces so that you can orient the details better, or that it will create easily-sandable surfaces where you can place supports while getting the details oriented upwards.

Another thing with the automatic generation is that if you have separate meshes that are intersecting that will be printed as a single object then sometimes it can place supports inside the mesh where it’s technically not needed since the parts will be merged when printing. It’s another reason the automatic method doesn’t always do a good job. The red marking for showing how well something is supported doesn’t always do a good job either in that some areas will show as red even around a support., or it might not highlight areas that don’t have any support just because a support is nearby but not actually supporting a point.

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I agree with everything Zach said except one thing… I orient the part and let PreForm generate supports, and then I go in and edit them. For larger objects, this is much more efficient than manually placing 100s of supports.

Self-intersections should really be eliminated in the CAD file. If you’ve got any that result in supports terminating inside the body of the object, IMO it’s worth the effort to clean up your geometry to eliminate the error so you can leverage the automatic support generation when setting up a new print.

I use a similar workflow to both @Zachary_Brackin and @DavidRosenfeld when setting up objects. I’ll typically orient them in a way that doesn’t necessarily minimize supports, but places them in such a way that they’re easily removed. I then use the auto support tool and manually remove or add them to capture over and under-supported geometry. PreForm will shade your model red in potentially under-supported regions but even that feature is relatively conservative and I often get away with printing models shaded with a fair bit of red.

I do an automatic generation, but usually have to remove most of the supports it generates anyways, along with the issue of having supports inside the geometry sometimes.

It’s not necessary to merge geometry–I use 3ds Max and to do that would be a Boolean operation which very often produces geometry issues. Since the printer works just fine with intersecting geometry it’s much easier to build things out of multiple meshes. It’s not often that the supports end up inside the print (since it does try to treat intersecting parts as a single object) and because of the problems of using Booleans it’s not worth the hassle.

I agree with the others. I let the program determine initial support locations after orienting the part so that the finish side is up and without supports. I use a point size of 0.4mm.

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