alanc
off to a rocking start
Member since January 2004
Posts: 12
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Post by alanc on Feb 23, 2004 15:34:38 GMT -5
Just got it rolling yesterday. I wish I had a digital camera, I'd post pictures. (I'm real proud of it.)
It's like an elongated Thumler's, using 4-foot rods as axels, and turns 4 barrels at once. I made the barrels out of 4-inch PVC pipe coated on the inside with silicon caulk--it's really quiet. I have the ends sealed with big rubber sink washers and screws, sort of like the way Thumler's does it. Totally leak-proof, so far. I had an old fan motor, and rigged up pulleys and vacuum cleaner belts to gear it down. The whole set-up maybe cost $80. I imagine the motor won't last forever, though, running all the time. That'll brobably set me back another $80 or so.
I think maybe I should have used 6-inch pipe or bigger, but this works pretty well. Each 11 inch barrel holds maybe 60% of what my big Thumler's holds.
I'll let you all know how the finished rocks come out!
Alan
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Post by sandsman1 on Feb 23, 2004 17:00:13 GMT -5
alanc sounds like its gonna work real nice only thing i can think of that would make me not want home made barrels is the noise and you got that fig out and you can find a motor for that alot cheaper if you bargain shop alittle if you get stuck give me a yell i just got three real cheap ill turn ya on to the guy see what he offers to sell for he said hes got a bunch ok seeya john
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Post by stoner on Feb 23, 2004 20:46:41 GMT -5
Hey alanc. I'm just about done designing the exact setup you built. Since you got yours running already, I have a few questions if you don't mind. 1.Did you use any type of support in the center? Each barrel weighs about 6lbs. and it seems the rollers would sag in the middle. 2.Are you using any type of bearings or something to keep the barrels separated? I've been using a homemade tumbler (single barrel-4" ABS) and it has been doing a great job, but it is alittle noisey. Let me know if the lining on yours holds up. It seems to me that the rocks and grit would knock it off fairly quickly and also the grit would stick to it. later, Ed
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WarrenA
fully equipped rock polisher
Member since November 2003
Posts: 1,530
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Post by WarrenA on Feb 23, 2004 21:52:15 GMT -5
All Right!!!! get some pictures and send them in, can't wait to see it. I like the idea of the vacuum belt it should last a long time. How many amps does the motor pull it should say on the label on the motor. Another good idea with the caulk on the inside of the barrels. I am very curious on how long the caulk will last, but it is cheap enough to repair and not worry about.
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alanc
off to a rocking start
Member since January 2004
Posts: 12
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Post by alanc on Feb 24, 2004 9:38:51 GMT -5
Ed, I used 3/8" rods for axles, so they'd be way too flimsey without in-between suports. I made the 5 supports out of wood, drilled out so that 3/8" (inside diameter) nylon bushings would fit snugly inside the holes. Sort of like the nylon bushings on the Thumler's units. You can get the bushings at Lowe's or Home Depot.
For the drilling, I clamped all 5 blocks together and drilled through them all at once so the holes would be true with each other. (Be sure to number each block so that they stay in order.) Then I glued in the nylon inserts with a tiny bit of silicon caulk. Before you glue or bolt the support blocks onto your base board (I've been afraid to glue mine so far), line them up on the base board with the axle rods running through them and twist the rods to be sure they're not binding. (Of course, be sure the rods are straight before you insert them--just roll them against each other and work with them until neither one bows.) Then clamp them all down to the base board and drill vertical bolt holes through the tops (and/or glue them, if you're confident enough).
Having said all that, I think now that instead of having the rods go through all those holes, I'd just have holes on the two end blocks, and have cradle-like supports for the three support blocks in between. That way, you wouldn't have to worry so much about having them spot-on--they'd tend to bind less. I'd maybe just cut a 1-inch "v" in the tops of the wood blocks, and line the notches with a couple of little strips of plexiglass (which you can cut like wood, pretty much).
I don't know how the caulk will hold up inside the barrels. I scored the insides really well with real coarse sandpaper and used the top grade silicon from Home Depot. (The tubes have varying levels of adhesion--I got the $5.00 "Silicon II" lifetime/forever stuff that says "oustanding adhesion" on it.) I've had to pull that stuff off of door jambs and it's like iron, but who knows how well it'll stick to PVC.
I coated the insides with probably a 1/8" layer of silicon. I used rubber surgical gloves and used my fingers to make lengthwise "gullies" in the silicon so that the rocks will tumble real good. I can't believe how quiet it is. It's about 1/3 as loud as my big Thumler's (A-12?) rubber barrel. It's so quiet that--if the silicon holds up--I'm going to bring it into the house this summer. (In Dallas, garages get plenty hot--too much stress on the motor.)
Hope this helps, Ed. Let us know how yours comes out!
Warren, my motor is 1/8 horsepower, 1550 rpm and pulls 1.6 amps. It seems like about the right amount of power--no noticable strain on the motor. I think 1/10 or 1/12 horsepower would be plenty. The less amps you pull, the more economical, as you know. Some of those little motors pull 3 and 4 amps--lots of torque that you don't need, and I bet a buck a day in electricity.
Mine's geared with the pulleys to about 1:5, so it doesn't take much motor power. The barrels go around about once every 5 seconds. You can fine-adjust the barrel speed by the size of the rubber 'traction' tubing you use on the axles. I started out with 1/4" (outside diameter) tubing--get it at Home Depot or Lowe's. It wasn't moving fast enough, so I added some more tubing around the first tubing (1/4 inside diameter and 1/2 outside diameter)
If I did it over, I'd try a 1:4 pulley ratio and use bigger barrels, though I'm sure they'd be noisier. Might take a bigger motor, too.
Alan
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alanc
off to a rocking start
Member since January 2004
Posts: 12
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Post by alanc on Feb 24, 2004 10:10:22 GMT -5
Sorry, I said 3/8" axles above. I meant 3/16".
Alan
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thewiz
has rocks in the head
"What good is money if you don't spend it"
Member since January 2004
Posts: 735
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Post by thewiz on Feb 24, 2004 10:19:35 GMT -5
alanc do you feel that an rpm of 20 is enough. my lortones seem to go about 35ish. i've been getting parts ready to build one also. i have 1\2 stainless steel rods and two 24 inch conveyer belt rollers to take the weight and self alining pillow blocks
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alanc
off to a rocking start
Member since January 2004
Posts: 12
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Post by alanc on Feb 24, 2004 12:04:26 GMT -5
Wiz, that's something I've wondered, too. I made mine a little faster than my Thumler's, but the Thumler's is a much bigger barrel, so theres way more surface area going around per minute. I figured I'd just see how this goes and change it up if necessary.
I'm using the big Thumler's for Stage 1 and the smaller homemade ones for stages 2 and on. Since Stage 1 seems to take forever, I was thinking that a little slower might be better for the finishing stages so that I could have every stage finishing at the same time. My objective here was to have all stages in the mill at once so that whenever I finish a batch, I'm starting a new one. I may be kidding myself unless I start rounding off the rocks with a grinder before I start stage 1. Stage 1 is taking up to a month with the rocks I'm using--flint mostly.
Sounds like a Lortone really goes a lot faster than a Thumler's. I wonder if Thumler's has less breakage. Anybody compare the two?
That's a heck of a hotrod you're building, wiz.
Alan
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thewiz
has rocks in the head
"What good is money if you don't spend it"
Member since January 2004
Posts: 735
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Post by thewiz on Feb 24, 2004 12:28:58 GMT -5
for my barrel i have been trying to get strips of pvc from another 4 inch peice glued to the inside to help tumble the rocks with no luck at 12 and 6 o'clock. going to try liquid nails and shoe goo next
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RedwoodRocks
freely admits to licking rocks
Member since March 2003
Posts: 762
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Post by RedwoodRocks on Feb 24, 2004 12:36:41 GMT -5
If the Silicon Caulk does not work. I wonder if using the plastic dip stuff would work better. The Plastic Dip stuff is used to put a soft Plastic coating on tools. I used some stuff many years ago (16 years) on a pair of pliers. And, the plastic is still like new.
Just an idea. Cal
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thewiz
has rocks in the head
"What good is money if you don't spend it"
Member since January 2004
Posts: 735
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Post by thewiz on Feb 24, 2004 12:40:49 GMT -5
great idea was thinking that for the 1/2 drive rods for traction so the pvc barrels don't just slide on the spinning rods
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alanc
off to a rocking start
Member since January 2004
Posts: 12
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Post by alanc on Feb 24, 2004 13:32:33 GMT -5
I sawed 3 little 3/4'' PVC strips for my first one and just used PVC cement--squished them in and held them down for a minute or so and they're permanent as anything. After I siliconed the barrel, though, I realized I didn't need the strips--just made the furrows with my finger tips all around.
Alan
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WarrenA
fully equipped rock polisher
Member since November 2003
Posts: 1,530
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Post by WarrenA on Feb 24, 2004 13:56:58 GMT -5
I shoot for 35 to 40 rpm on the barrel, I was at 20 but found it to be to slow took forever to get anything done.
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Post by stoner on Feb 25, 2004 1:23:35 GMT -5
Thanks alan. You're right, letting the rods rest on V shaped blocks would be alot easier to deal with. I used that method when I made an outfeed roller for my table saw. I had a roller from a blueprint machine that had individual tires on it, (it was about 4' long) and the center support v block was all it needed. Hmmm... maybe I'll use that for my drive roller on the tumbler. The silicone sounds like it may work and the plasti-dip was a good suggestion also, I just don't want the stuff coming off and then have to deal with picking it out of the rocks. I was in our local hardware store today(Orchard Supply for those in Calif.) and saw some hard black rubber sold in sheets and different thickness. Maybe using contact cement I could line the inside with 1/8" rubber. Well, for me, building these things is just about as fun as the whole rock tumbling hobby is. Good thing I got laid off last month, I'd be going crazy if I had to go to work and didn't have the time to work on it!
later, Ed
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alanc
off to a rocking start
Member since January 2004
Posts: 12
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Post by alanc on Feb 25, 2004 12:22:29 GMT -5
I was just reading something that suggested Rhino Lining--the stuff they use to line pickup truck beds--for the inside if the barrels.
Also, from another website:
From: lapidary@mindspring.com Date: 04 Oct 1999 09:22:07 -0700 Subject: LapDigest #236 To: LapDigest@mindspring.com
<MSG5>
Subject: Home-Built Tumbler
I spent a little while doing your avoided search out of curiosity because I have made several tumblers and wanted to see what other's looked like. I gave up after a while and decided to answer your question myself...
Our goal is to rotate a cylindrical container containing rocks, water, and grit/polish (working thru a series of grits/polishes with cleaning between) to bring the rocks to a high polish. Rubber lined containers are probably the best. Plastic can be used. With metal containers you probably need one for each grade of grit/polish to avoid grit/polish grade contamination.
The classic tumbler rests the barrel on two revolving shafts, one driven, one free. The rotation of the driven shaft revolves the barrel, which then drives the free shaft. A motor is pulley/belt connected to the driven shaft. The power train -- motor RPM, motor pulley/shaft pulley ratio, shaft to barrel ratio -- causes the barrel to rotate at an appropriate speed; a four inch barrel rotates 50-100 RPM, bigger barrels more slowly. I suggest keeping towards the slower end of the range.
Start by finding a barrel. The widest part of the outside needs to make a cylinder. Narrower in the middle (wider top and bottom) is ok if it is the same size cylinder at the ends.
Get a motor, wire, plug, and switch so you can hook it up, plug it in, and start or stop the motor.
Visit your hardware store and get four bearings that can be surface mounted and two matching shafts at least 4 inches longer than your barrel; 3/4 or 5/8 inch diameter shaft works. Get a couple of V-pulleys for the shafts -- 2 1/2 inch for one and 8 for the other is a good guess with a 1750 RPM motor, 5/8 shaft, and 10 inch barrel. Pick up a belt long enough to connect half the barrel diameter plus half the motor diameter. Pick up nails, screws, etc to put it together.
Stop at your local lumber yard and get a couple 2x4s twice the diameter of your barrel. Pick up a couple sheets of plywood; one twice the diameter of your barrel X the length of your barrel cylinder plus about 4 inches, and one the diameter of your barrel X the length of your barrel cylinder plus about 4 inches.
Lay down the big sheet of plywood, set the 2x4s along the sides, and lay the small sheet of plywood across one end of the top. The barrel should fit on the other half and just slide between the 2x4s. Fasten it together.
Mount the motor on the top of the small plywood sheet with the shaft hanging off one side. Mount the two shafts about 3/4 barrel diameter apart on the other half of the top with bearings on the 2x4s; the drive shaft should extend past the edge the same length as the motor shaft and on the same side (and be the shaft closer to the motor). Big pulley on the drive shaft, small one on the motor, and the belt connecting them should be fairly tight.
Connect both shafts together on the opposite sides with the same size pulleys and a belt if you want them both to drive.
Hook up the motor, put on the barrel, and start tumbling.
I'm leaving the description of another type of tumbler, the 45 degree single shaft tumbler, for next time.
Kreigh Tomaszewski Mailto:Kreigh@Tomaszewski.net ________
From: lapidary@mindspring.com Date: 11 Oct 1999 13:21:35 -0600 Subject: LapDigest #238 To: LapDigest@mindspring.com
<MSG8>
Subject: RE: Home-Built Tumbler
In my first post I covered the traditional tumbler that has the barrel rolling on its side supported on shafts that support and drive it. This posting will cover the more difficult 45 degree tumbler. With this tumbler you can use an open top barrel making it great for schoolrooms (add some Plexiglas guards over the moving parts for safety in a classroom).
In this type of tumbler the shaft is attached to the bottom center of the barrel, and the barrel and shaft as a unit are tipped to a 45 degree angle, shaft down - open top of barrel up. The shaft is supported by a base block. The motor shaft has a small wheel on its end that rides on the bottom outside edge of the barrel to drive it. It can be made to spin faster by moving the drive wheel closer to the center of the barrel bottom or enlarging the size of the driving wheel.
The barrel and shaft are really a single unit. For a small tumbler you could use a large plumber's helper plunger) - the type that is shaped like a wine glass instead of a cereal bowl. For a big tumbler a steel shaft with a floor flange on one end, a circular plate attached to the floor flange, and the barrel base attached to the top of the plate. Fastening a holder (large bucket?) container that your bucket just fits into on the top of the plate is an easy solution and makes the barrel removable for cleaning. The plate will be used as the drive surface. For the plunger you need a washer shaped plate and a floor flange that you can slide down the handle and fasten on. It is important that the drive plate be at right angles to the drive shaft and be rigidly attached (and thick enough not to flex) - plywood works.
Get a motor, wire, plug, and switch so you can hook it up, plug it in, and start or stop the motor. You need to be able to fasten a small wheel to the end of the shaft. Alternately, the wheel can be on one end of another shaft that is pulley/belt driven by the motor - and this actually helps since most motors you will find are probably a little fast unless your drive plate is larger than the barrel by a few inches. The drive wheel and the plate make a pulley system, so you can figure a reasonable speed ahead of time and make your drive plate large enough, or reduce the speed with pulleys by using drive from the second shaft.
The end of the barrel shaft is going to support weight and needs a thrust bearing. The top end of the shaft can use a regular bearing. If you are making the plunger type you might be able to do without a bearing if you drop a large marble or ball bearing in the support hole before putting in the shaft (and lubricate the shaft with bar soap). Make sure the barrel shaft is long enough to support the barrel weight; its a lever and probably should be near the height of the barrel.
We're going to need a large cube of wood. Your shaft will need to be about the length of the diagonal of a face. Stacked 4x4s with side bracing can be used in place of a block of wood. For something large, you might want to use a concrete base with a 4x4 imbedded where the shaft will go. This base block will be fastened to one half of a board twice as long as it is wide (and at least as wide as the support block). The barrel will hang over the part of the base not covered by the block, which is there to keep the whole thing from tipping over.
With the base assembled, the shaft/barrel assembled, and a motor we're ready to put it together. One side of the cube rises up from the base at its center. At the top center of this edge we're going to drill a hole 45 degrees downwards to the center of the bottom edge that is at the outside of the base. Don't drill all the way thru if making a plunger tumbler and make sure the shaft just fits the hole; otherwise drill a hole large enough for the shaft, mount the bearings (thrust bearing at the bottom, regular bearing at the top), and line them up with the shaft. The drive plate should be a little ways above the block when the shaft is inserted. If you are not using bearings, make sure the hole is smooth and closely fits the shaft - drill a smaller pilot hole first.
Mount the motor so that the wheel on the end of the drive shaft pushes up against the bottom of the drive plate at its edge. The axis of the drive shaft on the motor should point at the center of the barrel shaft. As the drive wheel turns, friction against the base plate makes it turn.
Hook up the motor, put on the barrel, and start tumbling. Don't fill your barrel too full or it will splash out the top. If the barrel has a small neck, like a wide mouth mason jar, that is a good thing.
Kreigh Tomaszewski Mailto:Kreigh@Tomaszewski.net
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Post by stoner on Feb 25, 2004 21:45:13 GMT -5
WOW! Nice reading. A 55 gal. drum and 3hp motor would be awesome on that 45 degree tumbler!
later, Ed
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