Ball mill motors

[moof]

Hello, I am trying to build my own ball mill and I'm shopping around for a motor on ebay. I know I'm looking for something in the 1/2 horsepower to 1/4 range but I'm not sure about rpm and other specifications. What is the ideal specs of a ball mill motor. Also, does anyone know a store that sells pillow block bearings?

-Thanks

[qwezxc12]

Basically your wish list should include: Capacitor start, fan cooled, & continuous duty rated. A fully enclosed case is best. Most motors of this type are 1750rpm, but you'll be calculating your optimum mill jar speed using pulley diameter, jar diameter, and drive shaft diameter, right?

 

As far as bearings go, either McMaster-Carr or Grainger carry them. I ordered my pulleys, 5/8" hardened driveshaft, block bearings, and idler roller all from McMaster-Carr.

 

http://www.apcforum.net/files/Ballmilltop.jpg

 

http://www.apcforum.net/files/BallMillback.jpg

 

Link to original post.

 

I haven't bothered making a set-up for the smaller jars...I never use them, because I grew into larger batches and never mill anything less than the capacity of the 6lb "small" jar (about 500-600g of any chem, except fluffier charcoals)

Edited July 28, 2008 by qwezxc12

[Mindphreak]

I made one out of k'nex and a pint sized paint can. So far it works great although I have not used it to make big batches yet. My biggest batch so far is 50 g not including the grinding media, however I'm sure it could easily take 200 grams.

[Frozentech]

5/8” pillow block bearings Grainger p/n 2X898 www.brooksco.com

5/8” Diameter steel rod 36” long McMaster Carr p/n 9120K16

Roller and Bracket set Northern Tool p/n 11295 www.northerntool.com

Sheave, 2” pitch, 5/8” ID" Grainger p/n 3X901 www.brooksco.com

Sheave, 6” pitch, 5/8” ID" Grainger p/n 3X919 www.brooksco.com

 

The ID of the 2" sheave depends on the shaft dia. of the motor you select, but Grainger has them in a variety of ID and OD.

[Swede]

Unlike the awesome motor pictured above, most of the motors I've seen on homemade mills tend to be too small, and of the incorrect type. A good, all-around motor for a modest ball mill would be TEFC (totally enclosed fan cooled) capacitor start for single phase, 1/2 HP or so, and thermally protected. Look for good ball bearings, not sleeve bearings that will require maintenance. An AC motor's speed depends upon how it's wound, and the frequency of the line power. They'll typically either be 1700 RPM or 3400 RPM, and since you are slowing the output with pulleys, you may as well make the job easier by going with a 1700 RPM motor. Be sure as well that it will run on 115 VAC and will not require 220-230V.

 

If the motor is not TEFC, then you might consider mounting a cooling fan, like a muffin fan, inline with the ventilation holes. Look also for a mounting plate welded to the motor case. Some motors have "face mounts" and would be very difficult to mount and adapt to your mill frame. So a summary:

 

TEFC

Ball bearings

Thermally protected

continuous duty

1/2 (or more) HP

Capacitor start/run

115VAC (or whatever your mains are)

~1700 RPM

and a mounting plate

 

If you can find an "explosion-proof" motor with the above features, even better. Good luck!

[Mumbles]

Just out of curiousity, what is the advantage of capacitor start over a non-capacitor start? Is it just to provide extra power and torque in the beginning to get it spinning?

[jacob]

Exactly, that way you can start you mill remotely, without it (and without assistance) the motor will just sit there, get dangerously hot and maybe trip a breaker.

[Swede]

Another simple way to look at it, a lot of motors on eBay (or surplus) are three phase, and 99.99% of homes have single phase. A three phase motor is useless in a home without a converter. Because three phase motors DO NOT require a capacitor, if the description of the motor says "capacitor start" then that pretty much guarantees it is single phase and good to go.

 

Look for cylindrical protuberance(s) on the body of the motor... they are capacitors. If they do NOT have them, the motor may still be single phase, and OK to use, but if they DO have them, it is pretty much assured.

 

Here is a pic of a motor with a capacitor in a shell, welded or bolted to the can:

 

http://www.harborfreight.com/cpi/photos/36500-36599/36550.gif

[marks265]

You don't need 3 phase on the line side (the power supplying the drive). I am running 115 volts AC to the drive and I bought a 220 volt AC 3 phase motor for the load side (motor connections).

 

If you would like to ask more tech questions visit this link and call them if needed.

 

http://www.wolfautomation.com/Product.aspx?ProductID=23167

 

Because I did not know how much work (amperage) I would need I bought the half horsepower drive and adjusted some parameters to reflect a smaller motor which I am using a quarter horse power. I felt if I ran into trouble buying a second motor alone would be cheaper than buying both a motor and a drive if I needed more power or the pyro machine got bigger!

 

I think one of the pics had a clear picture of motor specs. If not just ask me.

 

Cost was about ;

 

$150 for the drive (less if you bought the smaller drive)

$142 for the motor

$83 for the NEMA 4 enclosure

$6 for back panel of enclosure

$20 for the cooling fan

$6 for a small roll of wire

a toggle switch I had

$10 for a speed pot (potentiometer)

$2 for the knob for potentiomter

$5 for 5 feet of 4 conductor 14 awg copper wire

$15 for cord grips

$10 for an extension cord

$1.50 for cable restraints to hold cord to cabinet

 

$450.50 total for electrical

$450.00 total for hardware

 

$900.50 total TO BUILD THIS plus gas for the many road trips!

 

Everything was bought new. I can't stand messing around with used stuff anymore. If you were to shop around on the net and dig around your house I'm sure you can do it cheaper.

 

The speed pot is a 10K ohm linear potentiometer that uses a 10 volt DC signal from the drive.

 

 

Another simple way to look at it, a lot of motors on eBay (or surplus) are three phase, and 99.99% of homes have single phase. A three phase motor is useless in a home without a converter. Because three phase motors DO NOT require a capacitor, if the description of the motor says "capacitor start" then that pretty much guarantees it is single phase and good to go.

 

Look for cylindrical protuberance(s) on the body of the motor... they are capacitors. If they do NOT have them, the motor may still be single phase, and OK to use, but if they DO have them, it is pretty much assured.

 

Here is a pic of a motor with a capacitor in a shell, welded or bolted to the can:

 

http://www.harborfreight.com/cpi/photos/36500-36599/36550.gif

 

 

I disagree! A 3 phase motor is not totally useless at home. Please refer to my quote and the rest of the thread (http://www.apcforum.net/forums/index.php?showtopic=2306) that I pulled this from. I usually hold back from replying to these types of things because it is not optimal where the budget is concerned but is the ultimate in speed control for AC motors.

[qwezxc12]

I dug up the material list that I ordered from McMaster-Carr for my mill and attached it as a picture below. I used the 2-1/4" OD pulley for the motor, IIRC. You can also see I used a conveyor roller for my idler roller. Much cheaper than another shaft, hose and pillow-block bearing set. It works great. My motor is 1/2hp and was a display model at Harbor Freight; got it for ~$60.00, I think.

Edited July 29, 2008 by qwezxc12

[TheSidewinder]

Pretty good deal, I'd say.

 

Your parts cost about $75 less than my Lortone Tumbler.

 

And by building it yourself, you got a real Ball Mill. Not bad!

[qwezxc12]

Well, you have to add the other stuff in to be fair:

 

~$9 for 14AWG SO cord, plug, single pole switch and duplex j-box

~$20 for misc hardware (deckmate screws, brackets for conveyor roller, idler wheels to keep the jars centered on the rollers, nuts/bolts/washers/hinges to mount motor)

~$10 for 3/4" finish plywood and 2x4s

~$10 for odds and ends (gorilla glue, V-belt, etc.)

 

So, add around another $50 to finish it up. Plus, I went with the Lortone jars, rather than make PVC mill jars, so those were something like $55 and $42 ea...then add for media. I think the media for the big jar cost ~$80 alone. All I had before I built this was a Lortone 33A, so stepping up from 150g of passable BP in 15 hours, to 1200g of kick-ass BP in 6 hours was worth the effort and the cost.

 

Still, it's a cheaper hobby than golf...

[Swede]

Marks, I know where you are coming from re: the 3P motor. A small VFD + 3P is an awesome setup, but wouldn't you agree, budget-wise, that it is more than most people want to spend? A new Hitachi VFD for a 1HP 3P motor will run about $200, then the motor, another $100. eBay would be cheaper, but I would be concerned buying a used VFD on eBay. Who knows what sort of glitches or problems it might have?

 

I was concerned that someone who didn't understand motors would buy a three-phase motor by accident, not knowing it wouldn't work at home without support equipment. The 3P motors go really cheap on eBay, and for someone who wasn't aware of the difference, it could cause a lot of grief.

[Bonny]

Exactly, that way you can start you mill remotely, without it (and without assistance) the motor will just sit there, get dangerously hot and maybe trip a breaker.

 

 

I start my mill remotely and it isn't a capicitor start. The motor I have is off a barn exhaust fan. It is ONLY 1/15 HP, spins at 1075 RPM and is reduced about 6:1 with pulleys to slow the roller down. I regularly mill batches of 1lb of comp, plus media. The only problem with the motor is due to its intended use as a fan motor, it needs a cooing fan, for which I use a 120V computer type fan. W/O the fan it will overheat and shut off. In winter here in the Great White North, no cooling is needed though. I am going to rebuild (enlarge) the frame one of these days but the I'm happy with its performance...it's been chugging away for almost 3 years.

[marks265]

Marks, I know where you are coming from re: the 3P motor. A small VFD + 3P is an awesome setup, but wouldn't you agree, budget-wise, that it is more than most people want to spend? A new Hitachi VFD for a 1HP 3P motor will run about $200, then the motor, another $100. eBay would be cheaper, but I would be concerned buying a used VFD on eBay. Who knows what sort of glitches or problems it might have?

 

I was concerned that someone who didn't understand motors would buy a three-phase motor by accident, not knowing it wouldn't work at home without support equipment. The 3P motors go really cheap on eBay, and for someone who wasn't aware of the difference, it could cause a lot of grief.

 

 

I agree with ya Swede. I just feel it is unfair not to let people know of as many options as possible reguardless of cost. In my example a choice means to have many things to choose from and not just 2 or 3. With that in mind someone might have a motor laying around and all they need is the drive. Lots of possibilities from different people's worlds I guess. As far as the grief part goes you are right there too. But that is what good suppliers are supposed to do, is to help you through the grief.

[jacob]

I start my mill remotely and it isn't a capicitor start. The motor I have is off a barn exhaust fan. It is ONLY 1/15 HP, spins at 1075 RPM and is reduced about 6:1 with pulleys to slow the roller down. I regularly mill batches of 1lb of comp, plus media. The only problem with the motor is due to its intended use as a fan motor, it needs a cooing fan, for which I use a 120V computer type fan. W/O the fan it will overheat and shut off. In winter here in the Great White North, no cooling is needed though. I am going to rebuild (enlarge) the frame one of these days but the I'm happy with its performance...it's been chugging away for almost 3 years.

 

Really?, huh, I have a 3/4 HP washing machine motor sans capicitor, and it won't start a jar at all by itself, maybe the gearing on yours plays a part, mine is geared almost 1:1.

[Bonny]

Really?, huh, I have a 3/4 HP washing machine motor sans capicitor, and it won't start a jar at all by itself, maybe the gearing on yours plays a part, mine is geared almost 1:1.

 

I guess having the small pulley on the motor must give me enough torque to start it up.

[moof]

Thank you for all the replies. Can anyone tell me if this motor is suited for the job: http://cgi.ebay.com/RELIANCE-DUTY-MASTER-A...1QQcmdZViewItem

[smomi]

For my ball mill I use a pretty old supposedly washing machine motor. The thing is that it spins 8000 rpm. So instead of using regular switch I connected it with a lamp switch that can regulate how darkly or lightly the lamp burns. So now I can get the rpm down to normal. I also have this overheating problem. Could it be because of the lamp switch?

I'm already searching for a new motor that has correct rpm already. Passfire calculators really come in handy .

[Swede]

Thank you for all the replies. Can anyone tell me if this motor is suited for the job: http://cgi.ebay.com/RELIANCE-DUTY-MASTER-A...1QQcmdZViewItem

 

Moof, that motor SIZE is great, but it's a 220V three phase motor. Note that the plug has FOUR prongs, not three. One is ground, the other three are T1, T2, and T3, the three "legs" of the three-phase power. Unless you have a phase converter, or have three phase power in your shop (very, very few homes have 3P) it won't work.

 

Here are some suitable motors:

 

Motor 1

 

Motor 2

[Arthur]

The lamp dimmer idea will slow the motor BUT will cause it to overheat. Use the dimmer for fine speed adjustments, and get the pulleys close first so that all the dimmer needs to do is a max of 5% speed changes. -No get the right pulleys and dump the dimmer, it's heat, unprotected spark risk, and wasted power.

[Senz]

looking for a motor, i found one at a pawn shop, 1/10th horsepower, 850 rpm, will this work? 110V so idk if i would plug it into wall or what. help please?

[Arthur]

I've just spent less on a ready made rock tumbler than I spent on bits to not complete a ball mill! Unless you have space and a workshop buying is cheaper easier and likely to be more successful.

 

1/10hp is plenty for a small mill 800ish is too fast for direct connection but easy to get to 60 - 80 rpm with belt and pulleys. Is the motor that you see complete? Are you wise enough to check? does it need start or run capacitors?

[Bonny]

looking for a motor, i found one at a pawn shop, 1/10th horsepower, 850 rpm, will this work? 110V so idk if i would plug it into wall or what. help please?

 

 

If you are in North America, you can plug it into the wall, but in Europe they use 220/230 or something like that. Not sure about Austrailia...

[Senz]

perfect. im in canada.

 

but it it powerful enough?