I'm thinking of taking my products from on-demand to mass-production to lower the production cost and increase part complexity, but I'm not knowledgeable in all the different possible manufacturing processes, and I'm hoping someone could point me in the right direction to find out more.
What I'd like to find out is what process should I consider to focus on that would be cost effective with accurate results?
My products are used for taking panorama photographs, which require shooting 4-6 shots rotated around a very exact position with a maximum 0.5mm deviation. So far, SLS polymide has been very accurate. There has been some sagging around the holes in z-axis, but other than that, center points are accurate.
https://thomashuang.net/products/nps75/nps75.html
https://www.shapeways.com/model/730954
My "rotational" part design is extremely simple, where a coupling nut slides into the lower part, and the upper "ring" part rotates freely around it. Teeth keep them engaged, and a screw on top keeps them together. The reason why I've done this is that the SLS can't make threads this small, and can't create perfectly round holes and tubes that can rotated within each other.
But people are complaining about how they have to unscrew, lift, turn, lower, and screw again each time they want to rotate the camera.
So now I'm thinking about making a more complex rotator using metal inserts. The metal inserts would be designed to allow for the advantage of smooth rotations with an easy locking mechanism.
I think injection molding would be too expensive for a short run of 200-300 units. I've read that polyurethane casting is a good way to produce small runs, with the possibility of having metal inserts cast directly into the plastic. The only problem is that my designs have so many undercuts, I don't know how it would be possible to remove the molds after casting. But if I resolve the undercuts, would casting be much cheaper than SLS?
I am thinking about the possibility of making this out of metal. It would look like this:
https://www.shapeways.com/model/731440
I'm not sure about metal casting, but it sounds expensive, especially out of aluminum. I looked at Shapeways and i.competitive service 3D printed stainless steel but according to the process description, my unsupported rings would break or deform before getting to the furnace for hardening, and it would not give me the accuracy that I need.
I looked for digital metal laser sintering, and I see that i.competitive service has Titanium using EOS M 270 DMLS printers. Searching Youtube also comes up with videos of DMLS prints, and it looks like "real" direct printing. But the i.competitive service Titanium quote was 420 euros.... which is not cost effective.
So the question I'm trying to answer is, what process would be cost effective while allowing me to create more complicated moving parts while staying accurate to 0.5mm?