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Posted (edited)

I thought I would share some pictures of my ball mill.

 

Here it is, ready to run. post-18901-0-41464100-1406767730_thumb.jpg The whole thing, jar, box, & all weighs about 100 lbs., so I needed the handle & wheels to get the rig from my van the couple of hundred feet to the woodpile I use for a bunker. The handle is designed to come off for stowing in the back of the van. The box isolates the jar from the motor. post-18901-0-17023800-1406762235_thumb.jpg I can lift off the box for easier transport or service. post-18901-0-70746600-1406767739_thumb.jpg

 

I built it myself from pipe scraps, angle irons, bar stock, lumber, etc. I had lying around. I cast the bearing blocks from zinc.(I was going to use aluminum, but it wasn't heavy enough). The bearings & various nuts, bolts, etc. were from the hardware store. I got the wheels at Harbor Freight. The jar is made with 6” PVC pipe & fittings, as per Sponenburgh's design.

 

This 1/3 h.p. motor has plenty of power. post-18901-0-50325300-1406762236_thumb.jpg It was only a bit warm after 3 hours of turning the 40# jar. I got it new for $100 & free shipping from:

 

http://www.automationdirect.com/adc/Shopping/Catalog/Motors/AC_Motors_-_General_Purpose_and_Inverter_Duty_(0.25_-_300HP)/AC_Motors-General_Purpose,_Rolled_Steel,_IronHorse_(0.33_-_2HP)/1-Phase_Motors,_56C_(0.33_-_1.5HP)/MTR-P33-1AB18

 

Their service was great; it arrived 2 days after ordering.

 

 

There are three shafts, one drive & 2 idlers. post-18901-0-98221500-1406762235_thumb.jpg This is so I can run either a gallon or a quart size jar. The idler shaft on the left is the one for the Gallon size jar. The idler shaft on the right is the one for a Quart size jar( I haven’t used it yet ). The gallon jar runs at 68 rpm. Note that there is a caster that prevents the jar from rolling into the bearing mount.

 

All up, the total cost, not counting the jar, was about $140. The jar was another $30. The 30 lbs. of .500 lead balls were essentially free, cast from my stock of wheel weight lead.

Edited by Eagle66
  • Like 1
Posted

PVC Should Not be used, if that blows up (They can and they will if your not careful ) it will be like a big pipe bomb , and can injure you ,

I dont want to see a friend get injured, or killed, so just be careful please :)

Posted

Isn't PVC a very common jar material? If it's in a bunker like it ought to be, the risk is minimal.

Posted

The jar design, and the material choice is very common. PVC isn't a perfect material for a jar, both as it will produce shrapnel if there is an accident, and since PVC parts can rub against stuff and build a static charge. It's still used, a lot, and i think the reason is simple. There isn't really other alternatives that are significantly better, available for the home builder.

I would say the risks shouldn't be ignored, but they don't really need to take priority either. That type of jar is one of the recommended ones, and have been in use for.... Years.

I don't really like the band clamps, but i also don't have a good alternative. So it stays.

 

On the topic of the motor, and not getting very warm... Dude. Your motor is larger then your jar. Your far in to "overkill" territory ;- )

B!

Posted

Nice write up and mill, Eagle. As mentioned, PVC is most commonly used for mill jars but it does have hazards. You bunker it behind the wood pile, you're good to go. When I built mine, I opted to go with the Thumblers (Rebel 17) 15lb metal hex and rubber lined barrels. Sure runs a lot quieter with all that lead.

Posted

Don't fret about the PVC. It looks great!

  • Like 1
Posted

Yeh I agree, looks great!

I run dual 6" PVC and remote on and off. Just don't get in the habit of having lunch in front of it ;)... As all have said be careful and common sense tells you to limit your time near a loaded mill.

 

Great work!

  • Like 1
Posted

Nice ! and you can run two size jars, great for large coal compositions. I am working on tweaking mine to run a larger jar for large batches of TT, C6, spider stars, etc.

Posted

Dude. Your motor is larger then your jar. Your far in to "overkill" territory ;- )

B!

Well, it looked a lot smaller in the picture on the supplier's web site.

 

Mark

Posted

Nice design on the ball mill, as others have stated PVC is a well used choice for jars, if the ball mill is used in a remote location ( one of the important safety rules) an explosion will only ruin your ball mill not your life. Such unloading of jar should also be done in a safe careful manner with PPE being worn.

  • Like 1
  • 3 weeks later...
Posted

why would you want one so big?

 

A lot of BP is used in pyro for lift, burst and even some star comps. BP rockets can also use quite a bit of BP. It is the basic component of most fireworks.

  • Like 1
  • 4 months later...
Posted (edited)

Thanks for this. Your link to the motor is out, now it seems to be:

http://www.automationdirect.com/adc/Shopping/Catalog/Motors/AC_Motors_-_General_Purpose_and_Inverter_Duty_(0.25_-_300HP)/AC_Motors-General_Purpose,_Rolled_Steel,_IronHorse_(0.33_-_2HP)/1-Phase_Motors,_56C_(0.33_-_2HP)/MTR-P33-1AB18

 

Edit: Given the potential for sparking, are there any thoughts on using a motor drivcen by compressed air?

Edited by vizzer
Posted

A TEFC (totally enclosed fan cooled) motor is generally considered safe enough. You really should still be milling somewhat remotely anyway. TEFC isn't quite explosion-proof, but still quite safe. The enclosed motor will contain any sparks. AC motors really don't spark anyway, as opposed to DC.

Posted (edited)

A TEFC (totally enclosed fan cooled) motor is generally considered safe enough. You really should still be milling somewhat remotely anyway. TEFC isn't quite explosion-proof, but still quite safe. The enclosed motor will contain any sparks. AC motors really don't spark anyway, as opposed to DC.

 

Good bets for a ball mill motor:

-Totally Enclosed Wash Down (TEWD) Expensive

-Explosion-proof Enclosures (EXPL) Expensive

-SOME Hazardous Location (HAZ) Expensive

 

TEFC are very cheap: TEFC MOTOR 3/4 HP

Edited by dagabu
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