Tumbling is a good way to process large amounts of material on the sidelines, while you occupy yourself with other chores or frolicking in play. They are readily available turnkey, as well as easy to build on your own.
The principles are simple. You load the material into a mesh drum, which you rotate on its horizontal axis. The material tumbling about inside, breaks off the trichomes, which fall through the mess sides of the drum where they can be recovered.
While I have extensive experience designing tumblers for chemical milling Titanium, I've never personally designed on. Just as I was gathering the parts to do so, I stumbled across the Rosin Reaper, from which I designed the Grinning Reaper, and built it instead.
Soooo, I will describe to you what I've discovered to date regarding tumbler design, and promise to return to this page later with a DIY design for a ma and pa home unit, as well as an DIY industrial sized one.
In the interim, here are some pictures from my collection or from the internet to demonstrate my point. Both DIY and polished commercial. If you Google Kief Tumblers on line, you will see offerings from personal sized to commercial units processing 5 to 10 lbs per batch.
One of the purdiest DIY examples from my archives. No clue who the craftsman is, but my hats off to them.
Key visible features to notice, is the harvest tray underneath, and the door seal, as tumbling is a dusty operation. Not visible with lighting, is the insides of the drum itself, so lets look at another example that you can see inside the drum of.
Another DIY from my archives
The above picture shows stay bolts that separate the two ends of the drum, but they also perform another vital function for effective tumbling. Specifically they trap and hold the material as the drum rotates up and drops it once it starts over the upper swing of its rotation. Without this feature, the material would try to stay in one spot as much as possible and let the drum simply rotate under it. The material doesn't make it halfway up the drum before sliding back.
In a chemical milling application the stays would be short lived, so as an alternative we designed the sides of the drum as a hexagon, which performed the same function without dinging up the parts and corroding away.
This picture also gives a good idea of the drum suspension. One end sticks on the drive motor shaft and the other spins in a loop made from 3/" round stock. It could just as easily be a vee block, or a set of sealed bearing set in a vee, but the point is that the drive end of the drum is inserted and the idler end is just dropped into place.
A highly polished stainless commercial unit by https://thekiefthief.com/
A drive motor is required and rotation speed depends on the diameter of your drum, because the critical factor is surface feet, not RPM.
I've seen designs using everything from rotisserie motors, to angle head gear motors and Grainger.com has a good selection of the latter in both AC and DC.
Stainless mesh at: