My home-built rotary tumbler cabinet

A few weeks ago I mentioned in another forum that I had built my own tumbler cabinet.  Somebody asked for pictures, so here it is.

I don't consider it to be finished.  I have been running it for a little less than a year now, and have a few issues that I still need to resolve.

I chose to make the unit 3 shelves, but the motor is internal, occupying one of those shelves.  I have two sets of axles for running barrels.

The motor has a (roughly) 6:1 reduction to an axle on the first shelf.  This first axle transfers power to the second axle on the first shelf with a 1:1 ratio.  It also feeds an axle on the second shelf with a 4:5 reduction, so the second set of axles runs about 25% slower than the first.  I'm running 3/4" axles with (iirc) a 1600rpm motor.  These ratios mean that my top shelf runs 3lb barrels at 78rpm and 6lb or 12lb barrels at 44rpm, while my bottom shelf runs those barrels at 62rpm and 36 rpm respectively.  Lortone tumblers turn these barrels at 64 or 30 rpm, so my tumbler runs them a little faster than Lortone standard.  I may experiment with a further reduction to see if it makes a difference.

The whole tumbler frame can be removed from the cabinet for easier maintenance.  This is necessary if I need to change any of the belts or pulleys.

The interior sides of the cabinet are covered with a sound insulating material.  It does not seem to be very effective, but I have yet to add it to the cabinet doors.  Since it runs in the garage I haven't felt it's necessary. 

Having the motor internal to the cabinet means that all the heat generated by the motor stays in the cabinet.  I have put air vents on both sides of the cabinet and added a computer fan to pull air through the cabinet.  With the fan running, the internal temperature is several degrees higher than ambient.  Without the fan, internal temperature is 20 or 30 degrees warmer than ambient.  So I run the fan in the summer.  In the winter I shut the fan off, and this lets me run the cabinet even in temperatures well below freezing.  I guess I could add a temperature sensor and have the fan start or stop automatically based on temperature.  Maybe next year.

One mistake I made was in the width of the cabinet.  I cut the axles based on the usable width I wanted, after accounting for the width of the bearings and pulleys.  When I went to put it together, I found the pillow block bearings didn't let me get the axles close enough together -- 3lb barrels would fall between.  Other designs I've seen staggered the bears, but this would require extra axle length.  I couldn't make the axles longer without starting over (new axles, new shelves).  Instead I cut the feet of the bearings so they could sit closer together.  It worked, but it's a hack.

A problem I've encountered is that the thing is terribly filthy.  It generates a fine black dust that coats everything.  This is either the cheap aluminum pulleys being worn away, or the link belts wearing away.  I'm hoping that the pulleys and belts will wear together and stop wearing down.  Maybe I'll need to replace the pulleys with more expensive steel ones.

Would I recommend this is a project?  I'm not sure.  It was a fun project but I'm not sure it saved much money.  Given the cost of the barrels, motors, belts, pulleys and everything else, I don't think I saved much relative to buying several Lortone tumblers.  A pair of Lortone 33Bs, and QT66 and QT12 all together would cost around $800.  The barrels alone would cost half of that.  I did spend somewhat less than $400 on the cabinet, but only if you count my time as free.  So if you like building things, sure, it's a good project.  If building things is a chore for you, just buy a bunch of separate tumblers.

Here it is, in situ in the corner of my garage where it normally lives:

Here it is, pulled out into the sun:

And here it is with its guts exposed: