Why do you want to make a kief Tumbler if there are so many wonderful products perfectly manufactured out there. Give you an example based on my experience The Pollen master from Canada is one of the best ones out there .The PollenMaster150, formerly Pollinator, can process 150 grams at a time of leaf, flower or trimming per cycle. The entire process takes only 15 minutes and may be repeated if needed. The PollenMaster uses a 145mc screen however you may order one of our other Canadian made silkscreen drums in a 125mc or 165mc.The RPM on all the PollenMaster motors is 30-35, quite slow so that the crystals have time to gently drop through the screen. We are not trying to spin them through by force. if you want to see all the models visit PollenMaster Extractors