by spro745 on Thu May 14, 2009 8:17 pm
Well I have a few things to report on the burr swap. The fact is the round channel the stationary burr sits in is slightly smaller than the Mini burr, maybe .5mm at most. Thought of a few different approaches to this and broke out my Dremel with a proper bit and slowly ground this channel a bit larger, staying in as perfect a circular motion as possible. Did this little by little until the burr almost dropped in. Then finished it up with 150 then 400 grit sandpaper by hand. Now the burr lays perfectly in the channel and there is no play. Found the perfect stainless screws with concave heads that sit well below the burr edges. Easiest to modify was the spinning burr carrier, basically by first measuring with a digital caliper to center the Mini burr, then a final inspection by good old eyeballing. Drilled and tapped all holes and have achieved proper alignment. After assembly there is indeed a bit of space (maybe 1/8") between the burrs and I will first shim with cardboard to get an idea of proper thickness needed. Then will finalize it all by making a shim out of plastic of some type. Maybe even sheet aluminum. Something fairly easy to work with that will not crush under stress.
So far I see nothing that I'd consider a big deal for this modification. There was a comment made about grounds being trapped behind the burrs. The Mini burrs are dished out on the backside, whereas the PL burrs are solid. A quick and effective fix for this might be to put something on the backside of the burrs, maybe foam or something similar. Something that would be easy to work with, not permanent and will prevent grounds from building up anywhere. A good thick foam pad that would be held in place by the pressure of the burrs and simply fill the space.
As far as the inside diameter of the Mini burr not allowing the auger to feed the burrs quick enough....... I can't see any issue this could create, but if it does pose a problem I'm sure I can come up with a fix for that as well. I'll keep you guys posted. Later!