Good Product Manufacturer? - Page 1
Forum section: electronics / projects

author: SenSeS
author_rank: Contributor
timestamp: January 11, 2015, 09:01:03 pm
content: Hi,I’m working on a project that involves both electronics and CAD product design. I found a lot of information about how PCB’s are made and was very quickly able to have my electronic circuits fabricated for me. For my project I would however also need a custom casing around the PCB and I was wondering how I would go about having this manufactured. One option is to have it 3D printed but this seems like an expensive option and only worth the cost for rapid prototyping. I was therefore wondering whether there are companies that will take my 3D CAD design and manufacture my product for me. Does anyone know of companies like this? And what is the minimum order quantity for this (since I’m not planning to make a million cases, more like a couple dozen)? Thanks in advance!P.S. I'm located in Europe.

author: rx8pilot
author_rank: Super Contributor
timestamp: January 12, 2015, 06:02:36 pm
content: This is a very general question that will lead to hours, days, and weeks of questions.First, was your design done with a specific process in mind? machining, casting, injection molding, welding, extruding, etc...Is it confirmed to be manufacture-able by that process(es)?Has it been optimized for the process(es)?The answers to these questions will have a massive impact on the answer to your original question. There is no ballpark answer to your question with the info provided. Rapid proto is helpful to confirm size, shape, feel of a new design but not practical for much else. It is rough, and imprecise for real product release. Generally limited to plastics until you get into the very expensive processes.Short run of anything is expensive - the costs are dominated by setup expenses. So prototyping is never for the faint of wallet. 3D printing can help avoid mistakes, but you still have at least one round of prototyping to do. I have personally designed, setup, and machined thousands of parts when I was in that business (left it last year). It is slow and expensive.As the qty's go up, the price per part goes down as you probably already know. How much? Again, it depends on a myriad of factors. It was very helpful for me to do basic research on the various manufacturing options like sheet metal, extrusions, CNC machining, casting, etc so that my designs were not breaking the laws of physics. I could also have a reasonable conversation with the companies that may make the parts. You don't need to be an expert, but you should have an idea of what the strengths and weakness of each process as well as what design features are typical. If you walk into a sheet metal shop asking for a part that should be cast, you wont get very far. Also, if you have a mixed part/assembly that may require more than one manufacturer - you need to be able to coordinate the effort. There are very few manufacturers that invite people to walk in with concepts, they want actual manufacturing data. They do not want to be in a position where they have to interpret your ideas because you may reject the interpretation and create an ugly situation. ie "I don't like the finish", "This is a little looser than I thought", "These parts don't fit together", all of which I have seen countless times. Presenting an enclosure design for CNC that has small inside radii that are 8x taller than the radius will send you back to the drawing board - it's too difficult or plain impossible. On a side note, almost anything is possible if you throw enough money and time at it.Tolerances are deadly and they have to be settled based on the manufacturing processes. Imagine you have a slot for a PCB that is .063" because your PCB is .063". You have to have some space for a PCB to fit into a slot - they cannot be the exact same size. What variation can you expect on the PCB and what can you expect the variation of the slot to be? If you are machining from aluminum, the slot will get smaller when you anodize. How much? Depends on whether you choose Type II or Type III anodize - one is .007" thick and the other can be .0025 thick. This is the difference between the box working and not working at all. The learning curve is steep and therefore expensive. I got through it and you can too, as long as you are expecting some bumps and bruises along the way.Do some research. Focus on the prototype houses since they are more accustomed to working with un-documented, un-proven ideas. I am in the USA, so don't have specific companies to recommend.