> If you want to make a enclosure of a viewer of plastic, and it will be a complicated one, you have to deal with mould costs of at least 20.000 Euro's for each part
"Not so. I have a friend and colleague here that can make low-cost molds and castings from 3D printed originals that look like they were produced by a large manufacturing plant. His main line of business is in fact producing high quality resin copies of 3D printed originals which he first refinishes to remove all trace of the 3D printing process - leaving a professional finish."
I understand that method, is it with silicone? The method I was talking about is injection mouilding. So it depends on what method we are talking about and especally; series numbers, reproducable accuracy (less then ± 0,1 mm.) and post-processing of the casted part. There are numerous of methodes to make plastic parts, all having their specific pros and cons. So it is not the discussion what is the cheapest way to make a plastic or metal part. It is, I think, more important to have a list of requirements for that specific part physically and series size related. Then to make a choice what method is most effective.
The problem is that with stereo related products and mechanical moving parts, we require a high accuracy. Of coarse you can move the accurate related task to some comon available metal parts (gears) like Matey also does. So when producing it is often a balance and choice in the design and affordable production method for that specific serie number. When the serie number grows, what is the next production method, to make the part cheaper, faster to make, etc but keeping all the specs the 'custom made' part also had. And that little step, I am not talking about 1000 pieces, but just, say 100. is a chalange ;-) the comunity knows what you can make and pushes to make more and improve it. So this pressure asks to make a decision; sticking to the known 3D FDM technique or use an external 3D printing company, a kind of silicone casting like you said, or expensive injection moulding. Not even thinking about metal. With low numbers, metal isn't such a bad material to have it milled. The difference with 3D printing versus metal milling is that metal milling requires more tools, an expensive machine, skill to drive it and more external pre and post processing. As the numbers of guys having privately a CNC milling machine is much lower than those having a 3D printer, for milling you need to turn to a commercial company! ;-)
I know a guy, Co van Ekeren, I lot of you might know him of the camera's he joined. He lived 10 km. from me and was also very bussy with all kinds of techniques to build his viewers and camera rigs. In his time, the 3D printer was not available for the normal consumer yet. So he had a CNC portal milling machine for plastic and thin aluminium parts. But he also experimented with silicone plastic casting. He did make some analogue slide viewer enclosures with that technique but he seased using that as it was not accurate and had trouble with shrinking. And that was, I think, 15 years ago. I am not saying it is a bad techique, but for home use, like 3D printing it requires knowledge and and a procedure with designing and executing that process to have accurate reproducable parts. And it might frustrate when a process keeps failing after numerouse attempts! ;-)
Anyway, I understand what considderations Matej is facing. And he will get a lot of advices from this group and others what options he has. I have been using CNC metal cutting, CNC milling, FDM and SLA 3D printing, aluminium sand casting (most externally) for years. There are some interesting metal techiques which are interesting in low quantities (3D printing) such as the V-process aluminium casting. Which requires a mould (say 8000 euro's) but has the smoothness and thin wall abbility what you would expect from injection moulding! OK, this is just another option.
I think whatever is choosen, we might be happy that it is designed and made.
Thats it, have a great day all of you,