29 Nov Finishing metal with a vibratory tumbler
One of the unusual machines we have in a quiet corner of the workshop is a vibratory tumbler. It’s like a great big potato rumbler for metal parts and was designed and manufactured in Coventry, UK.
Our man Dick who has refurbished the vibratory tumbler and installed a new motor to keep it running for many happy years.
Increasingly we use laser or plasma cut parts in our ride manufacturing and whilst they are cut with almost perfect precision they do arrive with us with mill scale from the original rolling process and carbon and oxidation on the surfaces. All of these will make welding more difficult as you really don’t want carbon on the surfaces when it comes to welding them together.
A plasma cut metal part arrives and you can see the burred edges before treatment
What this little machine does is automatically process batches of components that require a separation of those components from the media it’s finished in. In other words, you put the components in, set the machine running and when you want them out again, the system separates them back out and delivers them back out looking clean, tidy and ready for welding. They are also coated with a rust reducing liquid, so when they do come out, they remain pristine.
Before and after showing the finish we need from the rumbler
The media is a tactile ceramic product and as you can see above, is an irregular prism shape or 3d angle cut triangle. To you and I, it’s just like a small Toblerone shape that has been sliced at an angle at both ends. This particular media is designed for deburring and edge finishing, but with a different media, it could be used to produce a highly polished finish instead.
Another close up of an edge showing a little spatter from the cutting process before the vibration surface finishing
The separation is perfectly Heath Robinson and simple using a mechanical flap which directs the media and components onto a separation grid. The grid has holes in it, which allow the media to fall back into the bowl and the finished components to be driven out of the side opening.
A whole pile of pieces about to go in for a second finishing
When you see it like this, it’s hard to get a sense of scale of the machine running. So to make that easier, here’s a short video of it in operation.