The main chassis for the my pan/tilt mount is made from 5mm steel plate. This is a rather difficult material to work with in my garage, so I opted for the services of some professionals with industrial size lasers and presses.
The lasers, as you would expect, are very precise. All the cuts are spot on. My main concern was with the bends. Even with a robotic press, bending thick metals can be a bit unpredictable. Even so, the bends came within 0.5 mm of where they needed to be.
I took the parts straight to the electroplater across the road and had him put a zinc coating on all the parts. The process cleaned off all the crumbs from the laser as well as the heat-scale and the zinc made them nice and shiny. Over all I’m very happy with the finish.
The parts are completely rigid, at least when tested with my puny human muscles. The structure should be capable of quite a significant load. The weakest point in the design will be the strength of the motors. This isn’t an issue if the load is balanced around the rotation axes.
The plastic bearing runs mate with the steel plate of the base and the chassis with six extrusions. The fit was actually quite tight, but after some squeezing they fit and stay together perfectly.
The steel balls fit the spacer perfectly as well. It takes a bit of force to insert them, but once they’re in, they stay in while still rolling freely. With all the balls inserted (I only have 9 at the moment), the spacer is sandwiched between the two runs. The two halves spin freely on the main bearing and the spacer doesn’t rest on the bottom run.
There is one last package to arrive containing bearings, nuts & bolts. Hopefully it will be here by the end of the week.