I am working on the third and final assembly piece for the Skateboard project, the hanger/axle!
Before working on the new part, I spent a few hours re-calibrating and testing all the probing systems on the VF1 due to some repeatability issues my boss had a couple of weeks back. What would happen is each tool's height would differ by two thou each time you probe it. After running through all the Reinshaw probing calibration and testing it many times, the machine finally gave consistent results of +-0.0002." I was then able to make these new parts with the little remaining time I had.
The skateboard hanger/axle part consists of a rod of aluminum with a hole straight through it and a few grooves that fit with the trucks' top grooves. It's a straightforward part in design, but machining it is a whole other matter. Because it's got a hole straight through it, I'm going to have to set it up on end in the mill and drill it out very slowly from one end to the other with a very sketchy five-inch drill. Then I can toss it on the 4th-axis to cut the grooves and drill the holes at the different angles.
My first step was to cut out soft jaws to hold the 1" raw stock aluminum rod in the Haas VF1 and drill out the center hole. I'm starting with the drilling before turning the outside of the part because the lathe at the shop doesn't have a large enough collet to hold the stock in and so will have to grip it from the inside of the hole once it's drilled out.
My boss suggested I start with a ten thou undersize drill and go halfway through the part, then flip it over and do the same to the other side. This way, when I come in with the final drilling operation, I can take one single pass all the way down and have an exact hole. I was able to program and machine the soft jaws in a few minutes but was limited and couldn't start the drilling.
I made a big mistake when cutting the soft jaws and accidentally put the parallel that spaces the two jaws apart too high up, and I accidentally cut a groove in them, making it essentially useless.