Nuts and Volts - June 2015

72 June 2015

PRACTICAL 3D PRINTING n BY CHUCK HELLEBUYCK

ecently, I purchased a low cost rotary instrument that is similar to a Dremel style tool, but far less powerful and a whole lot cheaper. I just needed it to drill small holes or grind off some plastic from a 3D print. The tool came with a whole bunch of tiny interchangeable bits. If I laid them all out on my bench top, there would be no more room for anything else. Since they were all round, a tiny bump to the bench would find them rolling on the floor. So, with the help of Tinkercad software, I set out to create a 3D printable tool stand customized for this specific device.

The design started out simple enough. Just a block with holes for holding the tool bits. However, after counting the number of bits, I found I would need a lot of these blocks, so I started stacking them like stairs. Before long, I had a back section that was half the height of the rotary tool — just perfect for a large slot to hold the tool when idle.

The bits came in two basic diameters: 0.090 inches and 0.120 inches. Then, there were different loose collets of various sizes for inserting into the rotary tool chuck. I located the 0.090 holes along the bottom rows, and the 0.120 holes along the top. In the front block, I added a tray for loose bits and larger holes to fit the collets.

Construction

I don’t think you can ever get a design right the first time. Not a problem if you have your own 3D printer vs. sending the design out to be printed. The print took about eight hours to complete, then I was able to test it out. It didn’t take long to find that the holes needed to be enlarged a little because as the printer builds the design layer by layer, it leaves ribs of plastic at each layer. The center of that plastic filament is at the dimension, however, it gets squished down a bit, leaving a little plastic inside where there should be an open hole. It made some parts

Organizing my bench is always a challenge. I like to

keep everything visible so I can see and use it without digging around. That requirement can easily make my bench messy as many tools are scattered about.