Yoseti,

Thanks so much for your post! This was very close to what I was designing after giving up on the drill press. I was going to fabricate it out of square hollow tube or an upright I-beam as the guy in Stuttgart. It looks like he is using two bearings, which I was going to use as well. It will make changing the belt harder, but could be better in the long run. I was going to use those adjustable link belts.

He doesn't seem to show a way to tension the belt (I'm thinking of hinging the motor) and I couldn't tell from the drawing exactly how the lower burr is adjusted.

But this is really inspiring and timely, so I thank you for letting me know.

dan

I've gathered the parts (scrapyard stainless uni-strut), burrs, bearings, motor, etc. to make a prototype. I decided to weld the frame out of stainless unistrut, bolt on two pillow bearings and a motor mount. The shaft is the most complicated part of the design with threads at two ends, slots for the pulley and the lower burr and a shoulder. I'll start with 3/4" material.

The only motor I had around was a DC 1/4 HP, which is less than I'd want, but its what I have. Speed controllable. The speed will be adjustable from 0 to about 800 rpm, though at low range it might not be powerful enough. I'll use an adjustment nut similar to OE's, but I won't have the shaft go through the bottom of the burr, relying instead on two bearings with a pulley between them.

Input on this thread has been very helpful. My meeting with my machinist friend was not! Next update will be with some luck, the finished working prototype.

I've been reading about seasoning burrs. A close look at the Robur burrs shows a lot of "wire edges" from the machining process. I wonder whether that is what must be removed for the burrs to be seasoned? If so, half an hour with the right tools and a steady hand would do it... I'm not going to to, however.

dan

I'm ending my contribution this thread and have started a new one titled, modestly, "Making a grinder using Mazzer Robur burrs". It became clear that a drill press, at least a cheap one, would not do the trick. So, I'm building more from scratch. I will make it hand powered to test and then add a motor, so it will be able to be used either way.