My latest feat of post-apocalyptic engineering. Post-apocalyptic engineering is when you use parts on hand no matter what. There is no going to the hardware store because THERE IS NO HARDWARE STORE!!
When I built the Girl Genius Radio Theater Microphone I had some brass plates water-jet cut and I bought a vibratory tumbler to polish them. The tumbler came from Eastwood and while it did a very nice job on the parts for the microphone, it failed shortly thereafter. When I took it apart I found that the bearings in the motor were shot, they had been destroyed by the vibration.
So I keep the two plastic bowls and the media that came with the machine and I set about making a new, tougher, vibrating unit. I began with the vibrating plate, which I milled from a scrap piece of cast aluminum I had hanging about.
I mounted a ball bearing in the plate that was a couple of orders-of-magnitude heftier than the original bearings. I mount springs, using what I had (watch the video to learn why this was a mistake!).
The base was made from a pair of old Volkswagen brake drums.
The flexible shaft was fabricated on my CNC mill. I milled a couple of flats onto the bottom of an old lathe chuck that I had and then clamped that in the vice. It made making round parts WAY easier than having to find the center every time.
Short plates with screw holes retained the springs.
The first offset weight I tried proved to be too heavy, so I fabricated this system to let me try different weights.
The 1725 RPM dryer motor was held in place with a sheet metal bracket.
The finished tumbler! Watch the video to see it in action!