Paradise Posted September 3, 2016 Posted September 3, 2016 I own a Shimpo RK-10 electric potters wheel. 200 watts 0-250 rpm. A few minor mods and it seems like it would make a great part time ball mill. I can throw 20lbs Of clay into an upright cylinder without hindrance. I used it to throw stoneware and terracotta plant pots for the flea market in the spring. Anyone have any suggestions on how to figure out what size and type of mill jar might be best suited to something like this? Btw it would triple as a star roller.TY in advance!
NeighborJ Posted September 4, 2016 Posted September 4, 2016 If you bolt a bucket to the wheel you can slide other buckets inside it to make for an easy cleanup, you can keep several buckets and media for different comps. See if you can mount it at a 30 degree angle so you won't need to change positions for star rolling and milling. Mine is set up this way and is a dream to operate. You'd be surprised how much you can mill in a bucket, I've milled 13lb plus 15# of media at one time. If you want a little more agitation, you can always glue a couple dowel rods to the inside of your mill jar(bucket). Mine is powered by a bandsaw but I'm sure the pottery wheel will work great. I also use two castor wheels under the top of the bucket so it won't sag.
Paradise Posted September 4, 2016 Author Posted September 4, 2016 What size and type of buckets are you using? You mean something like a couple 3 or 5 gal plastic buckets with a lid one set inside of the other? Do you have issues with air lock?
NeighborJ Posted September 4, 2016 Posted September 4, 2016 I use food grade 5 gallon buckets with the lid which it came with. I can fill it with water turn it upside down and shake it without a spilled drop. The Lowe's buckets work. I only need to take the handles off and zip tie one inside the other thru the handle holes so it will lock into the drive bucket, but a string would work.
Paradise Posted September 4, 2016 Author Posted September 4, 2016 AWESOME IDEA! Now this is what I love about this forum, GOOD practical advice. I'll give it a go and let you know how it turns out. TY
NeighborJ Posted September 4, 2016 Posted September 4, 2016 Can I safely assume the potters wheel has a sealed motor? I can't imagine it wouldn't be. Clay would play hell on the internal workings of a motor, I only ask because it would be nice to eliminate any possible source of ignition. Also check the speed control and switches for openings which comp can get in and start a fire.
Paradise Posted September 4, 2016 Author Posted September 4, 2016 When I Tip it up sideways the motor is exposed (there is no bottom) I was thinking a piece of a.c. plywood mounted over the bottom and maybe a plastic bag over the foot pedal?
NeighborJ Posted September 4, 2016 Posted September 4, 2016 The motor may need to breath so it won't overheat under load. I built a box around my bandsaw and fed air from a cheap 50cf bathroom exhaust fan into it. This keeps the box cool and under a positive pressure so no dust can get into it. The exhaust fan is outside and uses a flexible dryer vent hose to pipe air into the box. That foot petal may generate heat also, but if it is a remote petal you may be able to put it farther away so it isn't anywhere near the mill.
Paradise Posted September 5, 2016 Author Posted September 5, 2016 Wow, that sounds like the ideal way to run it. I was thinking of an old floor register.... Scrap that one! I've got the flexible vent hose 4" and a 4" inline fan 100 cfm. Would I need to use a speed regulator to tone it down you think?
Arthur Posted September 5, 2016 Posted September 5, 2016 There is an optimum RPM for each size of mill jar, typically these would be 60 to 80 rpm, but there is a formula to calculate the speed for your size of drum and media. For a star roller slow but variable speed is good.
NeighborJ Posted September 5, 2016 Posted September 5, 2016 There is no concern about dead heading the exhaust fan air, it will only generate a few inches of pressure inside the explosion proof containment box. As far as finding the optimum rpm for the mill, I've found that the easiest method is to load the mill with a given amount of media and cover the top with an old lid with a hole in the center just big enough to see thru. Turn the mill on and watch to see where the media is falling, you will want an rpm which gives the greatest fall without sticking to the outer walls or just rolling down the slope. After setting the rpm you can change the lid for a sealed lid and load the mill with comp. You may not need the explosion proof box if all you are doing is milling, the sealed bucket can be removed and opened in another area, but for star rolling it is a must.
Paradise Posted September 5, 2016 Author Posted September 5, 2016 THANKS all for your input. I'm going to set it up when I get home from work this weekend. As far as to glue a dowel on the inside of the bucket I assume this would be a very small diameter dowel? Just enough to grab some of the media. Seems like it wouldn't take much to get it really thumping. That wouldn't be ideal I take it.
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