The Dremel Lathe - Prototype

After the difficulty I had with the blue foam in the last project, I decided to try something a bit different.  In the absence of an accessible CNC router I decided to try my hand at building my own lathe so I could turn perfectly cylindrical blue foam columns.

I'd never used a lather before, and wasn't sure if ti would work with blue foam, so I decided to prototype it with Lego and see what sort of effects I could achieve without having to spend time and money building something that might not work.

I was actually kind of surprised by the results.  I was skeptical that the Lego would hold together under the speed of the Dremel, and also that it would be stable enough to get accurate shapes, but it performed well in both areas.  If the Dremel was set too high then there were some issues (check out 1:16 in the video), but at this speed the friction between the cutting tool and the foam caused it to melt slightly and change colour, so even if structural integrity was not a concern, having the Dremel set to 2-3 gave better results than 6-8 anyway.

I reinforced the part which fell apart in the first attempt and was able to make a few more cylinder.

There were a number of other kinks that I was glad I worked out in the prototype stage as well.  The method of attaching the foam to the lathe was an issue as if the two ends were not aligned or slightly loose then you would get an oval cross section rather than a circular one.

There was also an issue of having the pins I was using to hold the foam onto the lathe coming lose.  I solved this initially with a bit of tape, but after a while decided that if I ran a length of metal though the centre of the foam I could solve both problems.  Unfortunately I could find a piece of metal of the right size and length, so instead used bamboo skewers which worked quite nicely.

I also discovered that spinning causes friction, friction causes heat, heat causes melting.  Lego had a slightly higher melting point point than I thought, and after going through several of these pieces I decided to deign and make a MDF lathe.