My new tumbler!

[rfrey]

Hi! I've been in hiding for a few weeks while I prepared to launch my line of frames in Toronto in early November. I'm very excited! Some of you expressed interest in my processes, though, so I thought I'd update on my newest piece of equipment.

Because of some very generous advice from Jerry Huang, I realized my tumbler was too small (2' diameter) and I'd need a better one. So I ordered one! It arrived a couple weeks ago.



OK, it was more of a KIT than a real tumbler.

The design is like many commercial designs - round barrels rolling on powered steel rollers. First I laid up the steel for welding and got to it.



(continued)

[rfrey]

After a bit of sunburn the tumbler started to look like something. Not a tumbler, but something.



My company colors are red and black, so out came the spray bomb, and the base is done:



Next up: the rollers. I originally drew in 1" rollers to get the right speed reduction with my planned 42" barrels, but finding some deflection equations (thank you AGAIN, google!) showed that they would bend too much under the weight. So I'm using 1.5" rollers and a 2:5 reduction from the motor to the roller.

First I had to machine the ends of the rollers for the bearings. It was pretty hairy because they stick so far out of the lathe.



This is a problem because the bar will start to whip and centrifugal force will suddenly (and violently!) make it bend to 90 degrees, probably tipping my lathe over. However by blocking it with the bench I prevent the bar from whipping - it just pounds against my makeshift platform! It was kinda scary but it worked. Here's a pic of me actually machining the end.



Finally I mounted the bearings and pulley, and put it on the frame. Just have to add the motor and it'll be alive!


Next up.... The barrels.

[vcom]

This is great!!! Very exciting stuff! p.s. can I move in to your workshop?

[chaoticneutral]

Im in awe, fantastic

[rfrey]

OK, yesterday and today was spent on the barrels! I think it was a success, but I'll wait until they're spinning to uncork the champagne.

First I cut 42" disks from 3/4" baltic birch plywood and put dados for the octogonal barrel walls.



That center hole is for a vent, another hint from Jerry. I guess the heat can build up enough to distort the frames - I plan to put a computer fan on there for active air changing.

Next I cut the barrel walls from 1/2" plywood. Each end was beveled to 22.5 degrees. I inserted them all the way around on one side of the barrel, screwing them in from underneath.



The last wall segment had a port cut out of it, along with four holes. I put t-nuts into the four corners so I could screw on a cover with 1/4-20 knobs. The groove around the outside of the port is for a gasket in case I need it... much easer to cut that groove before the barrel is assembled.



With some coaxing from my Steel Persuader (big friggin' hammer), the top disk went onto the walls and was screwed down. I put it onto the tumbler rollers and it rolled sweet as you'd like. Good feeling!



The inside of the barrel needs some protection from the abrasive media that will be sloshing around inside it. Also it's better if the glasses have a bit of cushioning. So I rolled on two layers of rubber membrane in a can - usually used for roofs, etc. but I think good for this application too.



(continues)

[rfrey]

Only one picture left!

Finally I added some steel strapping to the edges. That helps keep the barrel walls tied together and prevents them from bowing out. It also helps keep the dust inside the tumbler.



Almost done! All that's left is to make the port covers and attach the motor!

There's a good possibility the steel rollers won't turn the barrels, but will slip on the plywood instead. If that happens I'll cover the edges of the rolling disks with the rubber compound to give it more friction, and maybe spray the roller itself with rubber compound.

[rfrey]

OK, basically done! Hurray!

I mounted the motor this morning. Took a bit more time than I expected due to belt length, etc. Ended up using an adjustable belt. Chose an explosion-proof motor because Jerry recommended tumbling with kerosene as a lubricant.



Wiring the motor also took longer than I expected, because the motor didn't turn when I expected it to! Turns out the thermal switch needed to be reset.

And away she goes!!



Let me know if you need anything tumbled!

[Hayde]

This was a freakin' awesome thread.

[Gizzo]

Kudos

[Boldt]

Amazing! I saw some of the ones you posted before and hope you keep us up to date with how you're doing. :^)

[JERRY HUANG]

You are da man!