Is there a method to part placement on the Form2 based on part geometry?

I was reading through FL website and found their “case study” on the pens they built for a trade show. They talked about how they built all the parts direct to the platform . But more interesting to me was how many of the cylindrical bodies they had per build based on the photos they showed.

This was interesting to me as i have a similar project where i’m building numerous cylindrical bodies that are 1/2" in diameter in 2 different lengths of 2" and 5". I plan to also build them direct to the platform with the axis of the cylinder going in the Z direction. So my questions are these:
–If i pack the platform pretty full, does it matter where i put the 2" cylinders vs. the 5" tall ones to make the build more succesful or to reduce the risk of issues? (ie. all the tall ones in the back, short in the front. stagger short-tall-short-tall in rows.)
–Since i’m building straight to the platform, is there anything i can do minimize any flash/bulging/lip on the first few layers?


Angles are your friend - Personally wouldn shy away from printing the models you described vertical unless other features on them were more important.
General rule of thumb for my prints are smallest initial layer to your model as well as the last produces the best surface finish.
Just my opinion though and of course geometry plays a large factor.

I haven’t encountered any issues with placing bigger parts in front or behind smaller ones, but there might be an advantage I haven’t seen yet… What I do is place the taller (Z axis) parts close to the wiper side, this slightly speeds up the print as the wiper doesn’t do a full swipe when only a part of the build surface is being sued and playing the parts close to the wiper lowers travel distance.

If you plan to print a lot of those though, my advice would be different : place the cylinders randomly and change the position for every print, or every few prints, this helps distribute the wear on the whole tank instead of using and wearing always the same spots.

While I havent tried it, reducing the Z offset might put less pressure on the parts but it will also adhere less strongly to the build platform. I have however been making chamfered edges on the parts which tends to mitigate this lip effect. You could also add 0.5-1mm of material and sand it down flat after post-curing.

If you are printing a lot of these cylinders I would separate them into batches of 5’ ones and 2" ones. The print time for the 2" will be less than half that of the bigger ones and any batches where the sizes are mixed will print in much the same time as batch of all 5" pieces.

Thanks for the tips everyone!

So my builds have been going ok thus far. However, last nights build didn’t do so hot.

Here is a basic image of what i’m trying to print for one of the parts:

Last night i had these parts mixed in with some basic straight cylinders of the same approx. 2" height.
These parts were built direct to the platform with the fin side at the build platform. Looking down from the top of my setup platform, each one was orientated like this:

The problem i had is almost of them suffered issues with the bottoms of the fin not building properly for the first .100" or so, then after that everything was perfect. :thinking:

When i built a single version of this part a few days ago, i had it orientated like this:

Would this ~45deg differece of rotation really make the difference in my test build being successful unlike my multiples build?? Or is it because i built multiple parts on a platform vs. 1 ?

A 45 degree angle in the Z axis is unlikely to have an impact on print quality. Can you upload a picture of some of the issues the fins ran into? Printing parts on the platform can be a bit tricky as the early layers have greater exposure and compression which could be contributing to the artifacts you’re seeing. These early compression and exposure layers end once the support raft finishes, but if you’re printing directly on the build platform, they could leave artifacts in your part.

The bottom edge of those fins should all be parallel to the table it’s sitting on.
The fins are only .030" wide…yes i know they’re thin. But like i said, this part did fine on a solo build. Only thing that changed is i rotated it slightly and built multiples on the platform.

I’d go with the flow and redesign the fins with a taper on the trailing edge :slight_smile:

It looks like cupping could be the issue here. Is the base of the rocket hollowed and flat against the platform? This could be creating a suction cup effect against the tank which makes parts harder to peel. This effect will be compounded by each part on the platform which could explain why you’re only seeing the fins begin to fail on platforms with multiple copies. The newest PreForm release (2.14.0) has a feature that helps to identify any large cupping sections.