As part of the cinema camera rig, I've been designing and making parts to assist me with operating the camera. It's a functional thing.
I design parts in 3D or CAD, depending on the part itself, and then either 3D print it as a prototype, or get it CNC machined out of aluminium. I have a 3D printer, which is handy to make things for proof of concept. But I don't have a CNC machine or milling machine (yet!?), so these I get made offshore.
One of the parts I'd been designing is a set of arms and handle bar that I can use to grab the camera with. Now, there are production parts that will do this kind of thing for you, but I thought it'd be good to try make something of my own and to learn about the process of getting things made out of metal. So I designed the arms and got them made.
I was quite impressed with their machining, accuracy and tolerance. Not so much with my measuring though. Silly me misunderstood how I'd measured the length required between the two handles, which led to the bar between the arms being the incorrect length. The bar had some extra 5mm length on the ends that went into holes on each of the arms. In the design however, I accidentally added the ends to the length, not take it off. So instead of having 5mm at each end lathed off, it was added, which made the bar section itself 10mm too long.
Now, there was no error in the fabrication itself. They made the part as per the specs in my file, and to the tolerances I gave. So the error was with me. The image above shows two versions of the handle bar, one with the incorrect length, and one with the correct length.
I put the grips on myself by the way, they're just fishing rod-style heat shrink grips. Actually worked quite well!
Unfortunately, I can't fix the machining issue myself. It could be machined down at one end, but I threaded the holes inside the ends, which means I'd have to drill further into the ends at the risk of damaging the threads. But I don't have a lathe in any case, so I'm not able to do it myself anyway. And to get a local engineer to do it would cost as much as to just get another part fabricated at the correct length. So, I ordered a new one.
I'm going to try and re-purpose the first bar and use it somewhere else, so it's not all lost. And I do have some ideas for how else I could use it. Learning as we go here, so I'm OK with it.