Ballmill speed issues...

[usapyro]

Anyone notice that the all the ballmills that are sold for rock polishing are WAY too slow for pyrotechnic use? I worked out a way to modify those ballmills. I just take rolls of black tape and expand the drive roller... Then finish with a layer inverted black tape sticky side out. It stays tacky and works as good as rubber for a long time.

 

Does anyone know of a place that sells high speed pyrotechnic ballmills or chemical grinding ballmills? I want to find a ballmill that can handle 5lb's of composition (Yes, composition... So that would be a 20-30lb ballmill I think...) that is high torque and can handle the amount of lead required for long duration runtime...

 

I was thinking about building my own but I have no idea what motor torque, rpm, etc I need...

 

These motors are nice looking here... I was just searching around and found this company. They sell every single RPM, Torque, and Gearing motor you can think of!

http://www.bodine-el...otor&Model=0649

 

Speed (rpm) 340

Rated Torque (lb-in) 25

Motor HP 1/6

Gear Ratio 5

$400

 

I have no idea when it comes to engineering though. 1/6th HP and 25 lb/in could be totally overkill for a 30lb ballmill... Or it could be too weak for all I know. Tempted to make a dual belt ballmill myself that can handle multiple different size bottles without slippage because of dual powered rollers.

 

Tired of playing around with small 3-10lb ballmills. Time for something bigger!

 

Was searching around some more and found these marathon series motors... These sound good (Marathon) and are simpler and not as expensive.

http://www.emotorstore.com/productDetail.asp_Q_catID_E_65_A_subCatID_E_467_A_productID_E_955

 

Hmmm...

Edited October 13, 2012 by usapyro

[usapyro]

Oh wait... Here is what I need...

 

Marathon Explosion Proof Motors: Single Phase Explosion Proof Motors

http://www.emotorsto..._subCatID_E_470

 

LoL...

 

 

Honestly, I'm too lazy to make a ballmill... I am thinking of adding either of these as the 3rd ballmill in my collection. Anyone have any experience with these mills?

 

15lb from hobfir

http://www.ebay.com/...sn=hobfir&rt=nc

 

 

15lb from pyrocreations

http://www.pyrocreat...l_mills___media

"NEW SPECIAL BUILT HIGH SPEED!

15 Lb ball mill (HEAVY DUTY) This is not like we used to stock. These are high speed tumblers with even heavier duty high speed electric motors. These run much faster then the old style tumblers we had before and much heavier duty electric motors but same style tumbler."

 

Sounds good...

Edited October 13, 2012 by usapyro

[Col]

I want to find a ballmill that can handle 5lb's of composition

 

A 3.6 gallon jar and 42lbs of 1/2" lead media would be about right.

Edited October 13, 2012 by Col

[TheArchitect23]

Have you thought about using DC voltage? You Can Have More Torque, Variable Speed.

my star roller is 90V DC Via a rectifier And Set Of Gears. which takes 115V and makes it Dc losing about 10-12V in the process.

Most All DC Motors ( 90V - 115 V DC ) Can Handle This Rectifier. Once You Have You're DC You Can Control The AC Side With A Speed Controller.

For A Less Than 10 Watt Motor You Can Use A Router Speed Controller, But Be Warned A Motor Rated Over That Will Blow Up You're Unit....

 

A Treadmill Motor, Controller Board, Or Rectifier, Router Controller, And A Sealed Box Around The Motor Should Be Enough For Variable Speeds ( Heavy Or Light Loads Like Switching Media )

[usapyro]

I think I am just going to buy one of these for now... Maybe next year ill think about building something bigger.

 

35lb from hobfir

http://www.ebay.com/itm/35lb-cap-Rock-Tumbler-Ball-Mill-Case-Debur-Polish-/261110815239?pt=LH_DefaultDomain_0&hash=item3ccb6ada07

 

Anyone around here have one of these?

Edited October 13, 2012 by usapyro

[TheArchitect23]

I once thought about one of those too. looks like a great deal. keep in mind tho they are not TEFC motors.

[Mumbles]

I once owned one of the 15lb versions. It worked very well. The 1 gallon jar took about 25lbs of lead, and produced a kilo of BP after 4hr of milling. Either model should be quite sufficient for what you want. Replacing the motor with at least a TEFC model would set some minds at ease.

[Algenco]

I think I am just going to buy one of these for now... Maybe next year ill think about building something bigger.

 

35lb from hobfir

http://www.ebay.com/...=item3ccb6ada07

 

Anyone around here have one of these?

 

you could build a mill for 1/3 the price

[usapyro]

you could build a mill for 1/3 the price

 

I have been searching around and just a motor costs as much as one of these ballmills... Unless your referring to buying a used motor from some other piece of equipment or something.

 

I'm too busy with work nowadays to dedicate too much time to this hobby. Id rather just focus more on my current business and take the money from the extra effort I put in and buy good stuff. I don't mind paying others for their effort if they are building good equipment.

[usapyro]

Nice... Four hours of milling produced perfectly milled grey meal?

 

I'm thinking of sticking with 1/2" lead. I have heard it mills faster than 3/4" even in the larger mills. Any thoughts?

 

I once owned one of the 15lb versions. It worked very well. The 1 gallon jar took about 25lbs of lead, and produced a kilo of BP after 4hr of milling. Either model should be quite sufficient for what you want. Replacing the motor with at least a TEFC model would set some minds at ease.

Edited October 14, 2012 by usapyro

[taiwanluthiers]

The issue with DC motor is that many of them (so called universal motors) have brushes which produces a lot of spark during operation, meaning any composition that gets inside is ignited. TEFC is recommended since they're enclosed so that there's less chance of stuff getting inside, but also the fan allows the motor to run for long periods of time without burning out. You can't control a TEFC motor so you have to build pulleys to get it down to the correct speed. The bonus is that the lower the speed you gear down to, the higher the torque.

[Bangkokpyro]

Anyone notice that the all the ballmills that are sold for rock polishing are WAY too slow for pyrotechnic use? I worked out a way to modify those ballmills. I just take rolls of black tape and expand the drive roller... Then finish with a layer inverted black tape sticky side out. It stays tacky and works as good as rubber for a long time.

 

A better solution is to remove the rollers and get some plastic or rubber tubing with an ID a fraction larger than the OD of the existing roller covering. Push it over the existing tubing ( you can apply some glue to make sure it stays in place and does not slip) and time the RPM again. If it's still too slow just do the same thing again with larger tubing until you get the roller OD big enough to turn your jars at the speed you want.

I used this approach to get a 15 lb 'gem tumbler' mill from 50 RPM to over 70 RPM. Original OD was around 1/2 inch and when I had put extra sleeves onto it it was 1 1/2 ich OD. Works well.

Edited October 14, 2012 by Bangkokpyro

[mickyp]

Self amalgamating rubber tape is good for rollers, you just wind it on tight and in a short time it becomes a solid rubber roller on your drive shaft and its a tight fit, you can also if you prefer wind it around your jar instead.

[Bobosan]

Some info that may be useful in ball mill design is located at;

 

http://www.mine-engineer.com/mining/ballmill.htm

 

It has a formula for determining optimal rotation speed for large mills but can also be used for smaller. I was searching the web for info on ball milling copper when I came across this information. Anyone do any copper ball milling?