What is the thinnest practical wall thickness that can be achieved without the part collapsing? Object would be (sorta like) a hemispherical dome about 1 - 1.25 inches in diameter, with no structural requirements.
That is going to be kind of tricky.
The Form 2 prints âupside downâ with the build plate (bed) on top. It rises as the print proceeds.
If the open end of the dome is facing up, it will catch a large amount of liquid resin (cupping) and that stress is likely to try to blow out the wall.
In the design software, you will want to have the open end of the dome facing up as it shows the build plate at the bottom of the view. Put supports from the rim of the dome to the plate.
Removing the dome after printing will take some care as you have to separate the tip of the dome from the build plate with a spatula. It may be best to have additional support to separate the tip of the dome from the plate.
An alternative is to try printing it on edge, but the stresses from moving the build plate sideways to break the recent layer from the tank as well as through the resin tank has been known to break some parts.
I know I did not give you a number answer, but the above has been my experiences.
1 Like
They mention adding a drain hole to hollow parts to combat the issue bill describes. Of course print orientation can also be used in the hemisphere case.
1 Like
People print lithopanes all the time with resin printers, so pretty darn thin. Is there a reason youâd want super thin walls, vs making the hemisphere 2-3mm thick?
Instead of printing it, could you repurpose something like a ping-pong ball?
I want to make the âdomeâ for a working 1:12 scale ceiling light fixture and it needs to be translucent enough to illuminate my scene. 3mm just isnât practical, but I can probably make it work with the 0.6mm to 1.0mm that the design guidelines seem to suggest.
It wonât actually be a hemisphere ⌠I just used that as an illustrative concept.
The clear resin can be finished to be relatively clear, unlike âclearâ filaments in the other printers. I donât know the light youâll use or the size of the scene, but even 1.5-2mm thick is probably not going to block much light. It can be helped out a lot if you polish the part, but that depends a lot on part geometry⌠Iâve never been any good at polishing detailed parts.
Vacuform it?
I was thinking about using white resin so I get something that diffuses the light a little. But I admit that Iâve never even seen the white resin so I could be way off here.
Good suggestion! But I actually envision the shape more like the following (itâs a 1930âs era kitchen), and that wouldnât release from the pattern/mold. I will turn the base on the lathe.
EDIT: I will most likely put a small hole in the center/bottom of the âdomeâ and thread vertically into the fixture rather than using the top side-entry screws. That solves my âdrain holeâ problem ⌠and #00 screws which are realistically the smallest practical screws would be way too big for the top/side screws.
1 Like
If you incorporate a drain hole, it will probably be best to print it with the open end against the build plate. There may be some support material needed, but it will not be in the visible areas, so your clean up work is not as difficult.
If you cannot find a way to print it, you can vacuform the top and bottom separately and glue them together.
1 Like