I have two Thumlers, which are now retired, except for the drums. They do a good job of cleaning, but are too light in the arse for serious handgun shooters, as they lack capacity. The weakest link in the system is the rubber band that they call a drive belt. I have now resolved the problem.
I built my own tumbler, which carries two Thumler drums that are loaded to more than twice, perhaps three times the capacity they will carry on the Thumler base. It consists of two 1/2 inch shafts, thirty inches in length. Each shaft is supported by three pillow block bearings, and the drive shaft is turned by a 6" pulley mounted just to the side of the center pillow block. The motor, a 1725 rpm, 1/3 hp unit is mounted under the top deck, and carries a 2" primary pulley driving a 40" drive belt. Given that the shafts are encased in a piece of 1/2" heater hose, their outer diameter is .75", which mated to the 1725 rpm motor, 2" primary pulley, 6" secondary pulley, and Thumler drums, yields a drum rpm of 46 rpm, which works just right.
Initially I thought that given the fact that I was loading the drums MUCH heavier with lots more brass, and nearly full of water, I might not get good cleaning. I was wrong. I just upped the amount of soap and Lemishine, and the brass came out just as clean as ever. I can now do in one cleaning cycle, what once took me three.
The wife broke the digital camera, so I can't post pictures. I can tell you that I built the chassis of plywood and 2x8 lumber that I ripped and shaped as needed on my table saw. Everything else needed except for the drums can be bought on ebay. Once I learn how to make my own very large drum, I will build another one engineered to carry it.