12 replies to this topic

[Draco_Americanus]

last night i was useing my ball mill (lortone QT6) and it started making a scraping sound so i checked it out and found the bolt that holds the L bracket on fell off, this bracket has the slot that holds the drum away from the frame. It was dark and to my dismay whitnessed an arc from the drum's aluminum lid to the frame. my guess is this charge is being built up on the rubber drum in the form of static electricity, this of corse could be dangerus with a flammable mix in the mill. any one else had this problem?

[Bonny]

last night i was useing my ball mill (lortone QT6) and it started making a scraping sound so i checked it out and found the bolt that holds the L bracket on fell off, this bracket has the slot that holds the drum away from the frame. It was dark and to my dismay whitnessed an arc from the drum's aluminum lid to the frame. my guess is this charge is being built up on the rubber drum in the form of static electricity, this of corse could be dangerus with a flammable mix in the mill. any one else had this problem?

Doesn't sound good! If the bolt falling out caused the problem, put a lock washer on it or lock-tite so it won't fall out again. You should look into reducing the potential for static using increased humidity or a grounding strap of some sort. Do you have a pic of the ball mill?

[Draco_Americanus]

http://www.lortone.com/tumblers.html
mine is the QT6, i have my humidfier fixed so i am working on upping the humidity, I need to find my loctite and grounding the fame will now be planed, thanks

[Bonny]

http://www.lortone.com/tumblers.html
mine is the QT6, i have my humidfier fixed so i am working on upping the humidity, I need to find my loctite and grounding the fame will now be planed, thanks

See how that works. You may need a grounding string that is in contact with with drum and (grounded) frame to carry away any charge that builds up. Humidity is great at controlling static. We have static problems where I work from time to time and use grounding strings, ionizing blowers etc...but the best by far is humidity.

[dr thrust]

hope you don't mind me butting in, although its a well made tumbler, its not designed for the job its doing, with all that steel framework around the rubber drum you've got the beginnings of a "van Der Graff generator", better to sell it on and use the money to build your own on a wooden base, and also! tumblers tumble, you need something faster, so there!

[cooperman435]

Just a note to everyone, backing up Chris M's comment. I've found that quite a few people that I've sold lead media too, who have been using rock tumblers, have gotten back to me with either problems simply due to the weight being excessive for the machine resulting in slipping, or machines wearing out very quickly. Best idea is to make one, not buy something and use it for something it wasn't intended for!

[Draco_Americanus]

whats funny is i have seen the cheaper china made rock tumbblers advertised on fireworks web sites http://www.pyrocreat...l_mills___media
I will add a ground strap and at the moment i cant build a replacement but i do have some parts i can work with. I use eaither ceramic or stainless steel balls and the media.
as for it running too slow? I thought the whole idea was to have the contents tumble?

[pudi.dk]

it's not only about the media grinding against eachother.
You want impact in your ball mill, which is a balance between too fast and too slow.
Too fast and the centrifugal force will keep the media against the walls resulting in little or no grinding.
Too slow, and it takes forever to grind, plus the media don't get the chance to drop at their full weight because there is not high enough cascading. Imagine letting a rock drop from a height of 1 meter, compared to dropping from 10 cm.

Edited by pudi.dk, 06 January 2008 - 01:01 AM.

[cooperman435]

I use eaither ceramic or stainless steel balls and the media.

WHY when lead is cheaper and safer? Also in my opinion its faster and better, due to the weight.

[Draco_Americanus]

I wanted something harder and less toxic then lead, i dont have a back building or shed to run the ball mill in so i dont want lead contamination in my home

[Bonny]

I wanted something harder and less toxic then lead, i dont have a back building or shed to run the ball mill in so i dont want lead contamination in my home

Why not use brass then? That's all I use now. I have a mess of different size and shaped pieces that work very well, heavy,hard,non toxic and non sparking.

[cooperman435]

I honestly think lead contamination is the least of your worries especially when milling in your home. The danger of heavy metals in your home is so insignificant especially when you asses the risks of milling bp with anything else in your house!

[Draco_Americanus]

too true, i have about a 5 pounds of mercury on my kitchen table(thats for high current switching for other experments) and i know the toxicy of some pyro comps is higher then just lead. but i had the stainless steel allready so why not use what i allready had? they worked poor for titantium, i can get a unlimited free sorce of titatium but its so hard to mill, i may try my ceramic next but i think it may fail as well, mady time to make a hammer mill?

also i dont use ceramic for milling BP, i have read that is a bit dangerus

Edited by Draco_Americanus, 16 January 2008 - 04:04 AM.