adrian65
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Post by adrian65 on Nov 21, 2008 11:58:38 GMT -5
Hello, everyone! Today I received the barrel for the tumbler I want to build: a Thulmers, 15 Lb, hexagonal barrel. It's a big upgrade for me, I only had a Lortone 3A. I know that many of you have home made tumblers. Would you tell me what type of electric motor did you use? I'm not interested about the brands, as I won't find them here, but I would find helpful to find out if some of you did use an electric motor taken from another device - washing machine, ventilator or anything else. Pictures of your tumblers are welcome here. Thank you for your help, Adrian
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Saskrock
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Post by Saskrock on Nov 21, 2008 15:46:30 GMT -5
I have been using old furnace fan motors, because I can get them free. The important part for any motor though is for it to be continuous duty or it will burn out.
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Post by johnjsgems on Nov 21, 2008 21:14:48 GMT -5
One thing to watch out for in furnace motors is they sometimes use "continuous air over" motors. They rely on the air the fan moves to cool the motor. They won't work without the air flow. You would need a motor that has a fan blade in the back of the motor. Thumler uses a tiny motor on the model B but Diamond Pacific uses a 1/3hp on their 12T which uses the same drum.
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Post by Hard Rock Cafe on Nov 21, 2008 23:01:11 GMT -5
Here is what I used before I bought my tumbler, because I have a couple spares from a heating system retrofit: www.bellgossett.com/productPages/Parts-SERIES-100.aspIt's a 1/12 HP continuous duty hydronic heating pump/motor assembly. I took the pump off. It was kind of a pain to mount because it was designed to hang off a pipe. It got hot, but ran fine. Don't know whether that helps. I've been told that washing machine motors work, too. Chuck
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adrian65
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Post by adrian65 on Nov 22, 2008 14:48:48 GMT -5
Thanks very much to all of you for advices. One more question though: what do you mean "continuous duty motor"?
Adrian
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Post by bobby1 on Nov 22, 2008 14:56:15 GMT -5
An imortant consideration is to use a large enough motor to turn the barrel under any circumstances. Most of the commercial units skimp on the motors to save on fabrication costs. You often have to fuss with them to keep them turning reliably (clean & oil the bearings, fuss with the belt tension, clean the belt and rollers, etc.). Because of this I made my own tumbler frame. I powered it with a 1/3 hp motor. It sure reduces the time and attention that I have to spend on keeping the tumbler rolling reliably. My tumbler has a 40lb barrel and this size motor works perfectly. Bob
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drjo
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Post by drjo on Nov 22, 2008 17:26:52 GMT -5
"continuous duty motor" is exactly as what it states, it can run 24/7/365.
Some motors are only for "intermittent duty" cycle (ie 50% duty cycle would be... on for 30 minutes, off for 30 minute (to cool)).
Washing machine motors are approximately 80% duty cycle, but under the lighter load of a tumbler seem to serve well and have the added feature of 2 speeds.
Dr Joe
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adrian65
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Post by adrian65 on Nov 23, 2008 0:56:51 GMT -5
Thanks dr Joe. I was afraid I might look for a continuous current motor.
Adrian
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Post by Jack ( Yorkshire) on Nov 23, 2008 2:49:55 GMT -5
Hi Adrian,
I have 2 units using old Central heating motors
The motor has provided power for a unit I run ,A 6lb Thumbler & Lortone barrell on which I built myself using some surplus 1" ball bearings and 10 mm S Steel shaft I got at a big industrial scrap yard in a 1" fibre board frame.
I covered the shaft with rubber piping to get a "grip" on the barrel
Final speed around 40 RPM
Have a good day Its snowing here and cold Brrrrrrrrrrrr
Jack Yorkshire UK
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drjo
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Post by drjo on Nov 23, 2008 8:53:11 GMT -5
Jack, can you post pix (with one showing the motor) of this Frankenstein tumbler ;D
;D ;D I just had a visual of you completing the unit and flipping the switch and screaming "IT'S ALIVE" ;D ;D
Thanks,
Dr Joe
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adrian65
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Post by adrian65 on Nov 23, 2008 10:43:48 GMT -5
... Its snowing here and cold Brrrrrrrrrrrr Jack Yorkshire UK Jack, you used to have the Gulf Stream didn't you? Is it sleeping? Thanks for the advices, Adrian
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Post by Jack ( Yorkshire) on Nov 24, 2008 3:50:02 GMT -5
Hi Adrian,
Gulf stream comes in on the west side we are on the East coast of UK, as my farther used to say "wind from the East , Not fit for man nor Beast"
Dr joe Not a big machine at all I will post a photo of it (or link) as soon as I can
Jack Yorkshire uk
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Post by rocklicker on Jan 12, 2009 14:25:43 GMT -5
I have a homebuilt tumbler with the same size barrel and use a 1/6HP motor. It's plenty strong. It doesn't even get warm. Consider that the bigger the motor, the more electricity you end up using. Steve
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adrian65
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Post by adrian65 on Jan 12, 2009 14:34:28 GMT -5
Thank you Steve. How did you get down the rotation speed? Some pictures would be very helpful to me, please.
Adrian
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chadman
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Post by chadman on Jan 12, 2009 17:51:34 GMT -5
Hello, everyone! Today I received the barrel for the tumbler I want to build: a Thulmers, 15 Lb, hexagonal barrel. It's a big upgrade for me, I only had a Lortone 3A. I know that many of you have home made tumblers. Would you tell me what type of electric motor did you use? I'm not interested about the brands, as I won't find them here, but I would find helpful to find out if some of you did use an electric motor taken from another device - washing machine, ventilator or anything else. Pictures of your tumblers are welcome here. Thank you for your help, Adrian Just one barrel? 1/6 hp should work. Furnace motors tend to be 3450 RPMs. A bit fast depending on how you want to reduce the speed. 1750 RPM 1/3 HP is what I use with a 2 inch sheave on the motor and a 9 inch sheave on the drive roller shaft.That gets me about 33 RPM. You can see my "little" tumbler somewhere back a few threads in this "home made equipment" area. I make my own roller shafts that end up 7/8 in diameter.
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Saskrock
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Post by Saskrock on Jan 12, 2009 21:16:15 GMT -5
Its usually the newer direct drive ones that are usually 3450, but they are also the ones that usually need air flow. the older belt drive ones tend to be 1750. The free ones I'm talking about are out of junked furnaces, not much new going on there.
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Post by Woodyrock on Jan 13, 2009 1:20:56 GMT -5
Adrian: Here are the formulae to determine speed of belt driven machines. Where, D = diameter of driven pulley, d = diameter of driver pulley (the one on the motor), N = revolutions per minute (rpm) of driven pulley, and n = rpm of driver pulley.
D = d X n/N d = D X N/n N = d X n/D n = D X N/d
For example, you have a 250mm pulley on the tumbler shaft, and you want to turn it at 40 rpm with a motor turning 1750 rpm. solution: D X N/n=250mm X 40/1750 = 57mm, round this to 60 mm, and turn a wee bit slower.
Can not wait to see the finished tumbler.
Woody
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adrian65
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Post by adrian65 on Jan 13, 2009 8:00:56 GMT -5
Thanks Woody. I think the formula is D x N = d x n, is it?
With this formula, it looks like if you have a motor having 1750 rpm and a driven pulley of 250 mm and if you want to get 40 rpm you need d = 40 x 250/1750 = 5.7 mm. Way to small, or in other words the driven pully would result a huge one for a decently small driver pulley.
But anyway, I don't need the shaft to rotate so slow, but the barrel. So the rotating speed of the shaft would be : nshaft = Dbarrel x nbarrel/dshaft
Let's say Dbarrel is 9 inches and dshaft is 3/4 inch, this means the shaft might rotate 12 times faster than the barrel does. So, about 40 x 9/0.75 = 480rpm (rotation speed of the shafts on which the barel sits).
Now, getting from 1750 to 480 with a pulley and two unequal wheels seems more easy than from 1750 to 40. The driven pulley might be 3.6 times bigger than the driver pulley, so 50 mm driver and 180 mm driven are some convenient dimensions I think.
And all of the above computations do not take at all into account the frrictions, thus the loss of rotation speed. But I think it's good to start from a theoretical rotation speed of 40, this way the real one might get close to that 30 rpm that most of you reccomended.
Anyone still with me? ;D
Adrian
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chadman
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Post by chadman on Jan 13, 2009 12:41:53 GMT -5
2" motor pulley and a 9" shaft drive pulley on a 7/8" shaft gives me 33 rpms with a 1750 motor. Decrease the 9" pulley to speed it up, increase it to slow it down. 33 rpms is okay. I prefer 30 but the cost the pulleys more than double after 9". Faster than 36 rpms and things are too rough for 1.5" plus material IMO
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Post by Hard Rock Cafe on Jan 13, 2009 12:52:46 GMT -5
I'm with you, but don't think you'll have much friction loss; at least, I haven't seen much.
The last piece of the puzzle is the actual rotation speed of the tumbler because the barrel diameter also determines rotation speed. Somebody correct me if I'm wrong. On the tumbler I built a 4" diameter barrel turned a lot faster than a 12" diameter barrel. This makes sense to me because the shaft rotations can be translated into linear motion of the barrel. A 1" linear movement on a 4" barrel (12.6" circumference) is a lot larger relative to the size of the barrel than a 1" linear movement on a 12" barrel (37.7" circumference).
So, back to the problem at hand. I got impatient with the calculations, so I just built it using the smallest driver pulley and largest driven pulley that I could find at the local hardware store (2" and 4", if memory serves) and the result was in the right ballpark for the barrel I was using. Theory is fine, but there's room for plain old empiricism*, too.
*Also known as "trial and error".
Chuck
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