Stovetop Coffee Roaster

My sweetie roasts coffee. She orders big boxes of raw beans from a site called Sweet Maria's and roasts them using a stovetop popcorn popper. She's got an automated hot-air convection roasting bot, but she says she likes manual stovetop roasting because it allows her to roast by sound and smell. It's actually pretty cool; as she explained it to me, there's the sound of the first crack, where water in the beans turns to steam, then the second crack, where the oils in the beans start to boil and the temp starts to increase dramatically, then you go by smell to get whatever roast you're after.

The problem is that she's gone through four or five popcorn poppers so far. They're made for stirring a batch of popcorn, which weighs a lot less than a batch of coffee, so they give out after awhile. She saw some of the parts I've been making for a CNC machine and said "Hey big boy, why don't you direct some of those bearings my way?" So this is my crack at solving the wimpy popcorn popper problem. If I can get my CNC machine working, we might even try making a cottage industry out of it. I thought I'd post it on the Interwabs because it included some cool fabrication experiments that someone out there might find interesting, or at least amusing.

31 allen head machine screws, 2 set screws, 4 nuts, 23 parts (mostly aluminum), and 36 1/8" 440 steel balls went into this thing. A little box made out of 1/4" thick 6061 contains 4 bearings and a clamp collar that locks an 8 mm steel shaft (one of the guide rails from a broken scanner we had... I'm a borderline hoarder of electronics and electromechanical junk) between two thrust bearings (bears loads along the shaft's axis) and two radial bearings (bears loads perpendicular to the shaft's axis).