What sets this trommel apart from my other is that instead of endless hours printing the main tube (which you might well break the minute it's called on to do any real work) is that for this one I supply the files for three drilling jigs which fit neatly over 4" waste pipe and allow you spend endless hours happily drilling instead. The three jigs are for 6mm 12mm and 20mm holes - the 20mm ones of which are first drilled to 6mm then run through with a 20mm hole saw. to enlarge them If you're not into metric fear not because the nearest imperial sizes will work equally well (1/4 1/2 and 3/4).
You'll need two 12v 37mm (1.5") gear motors for this thing. One to turn the trommel itself and another to drive the auger (which lives in the hopper), both of which I'm driving with a single 3A PWM controller. Look for motors in the range of 100-250 rpm for the trommel and 20-60 for the auger. Do a quick google search for "37mm 12v gearmotor" and you'll find plenty of suppliers and they're generally not too expensive. Err on the slow side for the motors if you want realism and endurance. NB: The motors shown in the video are NOT the same as the ones I just recommend above... I just happened to have those two slower/lower powered ones laying around and was too impatient to see built to wait for the faster ones to arrive.
One thing to watch for when printing is that the auger is a 2-part print. I can only tell you how I combined them in cura but other slicers more than likely have similar features.
Load both parts into your slicer.
Select only the screw part of the auger then using Cura's per model settings find and select the Make Overhang Printable option.
Select both parts of the auger, right-click, then Merge Models.
By doing the above the screw part (only) will have additional material added to it which helps greatly with bed-adhesion (not to mention strength and durability) while leaving the shaft to be printed without change.
Remember to come back and post what you've printed as Make.
It's good for the designer and the community (that means you)!
To post a Make, come back to this Thing and click Post a Make.
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and the Apple App Store.