Pyro09 Posted October 29, 2009 Posted October 29, 2009 (edited) Hi , I've constructed my new Ballmill some days ago (it is my fourth version with "bugfixes") and now I wondered whether I should install an insert in the yar to ensure proper mixing (I hope you know what I mean by "insert", I don't know the correct word). Do you use just the jar and the media without an insert? It turns at 80 RPM, the ID of the yar is 150mm ( ~5,9 Inch) Some pics of my ballmill: http://img94.imageshack.us/img94/4459/p1000904j.jpg http://img692.imageshack.us/img692/756/p1000905.jpg Greetings, PYRO09 Edited October 29, 2009 by Pyro09
FREAKYDUTCHMEN Posted October 29, 2009 Posted October 29, 2009 Almost same concept as mine, it would be better to have your motor outside the case, this way it won't cool very much.Mine is running at about 35rpm, mills most compositions within 3hrs into dust. I'm using a 8" ID jar. You don't need those bars. Just try and see if you like it, every ballmill is different.
Richtee Posted October 29, 2009 Posted October 29, 2009 Hey...that's a pretty cool build there! May have a point about motor heat- having the motor outside the box... as I think one of the things that will make it a more efficient mill is to cut the DC voltage to the motor and run it a bit slower. (I am assuming that is a DC motor) That will cause the motor to run a bit hotter.
Pyro09 Posted October 29, 2009 Author Posted October 29, 2009 Hey...that's a pretty cool build there! May have a point about motor heat- having the motor outside the box... as I think one of the things that will make it a more efficient mill is to cut the DC voltage to the motor and run it a bit slower. (I am assuming that is a DC motor) That will cause the motor to run a bit hotter. No, the motor doesn't get hot due to the fan right beside. Is it more efficient to run it slower? I think 80 RPM are ok..but I could run it also at 6V , works too!
AdmiralDonSnider Posted October 29, 2009 Posted October 29, 2009 Here are some guidelines for optimum efficiency (given by L.Sponenburgh): optimum RPM= 0.65* (265.45/((jar ID-ball OD)^(1/2)))jar ID and ball OD are given in inches optimum media load (balls) is 1/2 of empty mills volume optimum material charge (e.g. BP) is 1/4 of empty mills volume
dagabu Posted October 29, 2009 Posted October 29, 2009 No, the motor doesn't get hot due to the fan right beside. Is it more efficient to run it slower? I think 80 RPM are ok..but I could run it also at 6V , works too! PYRO9, Nope, I think it will be fine the way it is. Remember, the ideal speed is where the media crawls up the wall and cascades down with force to crush the chems. Lifting bars will help with this cascading but there is a dark side that some don't talk about... wear. Your grinding media will last a lot longer if it does its job the most efficient way without shortening its life. Smooth wall jars work great with sticky comps like BP but lifting bars would make short work of charcoal. I would stay away from lift bars. Take a look here: http://www.pyrobin.com/files/media1.jpg These are the best grinding media anywhere! Why? The weight of lead and the durability of copper. The media charge is more important than anything else so pay special attention to what you choose. If you have a 1 gallon jar, it will take 500 pieces of 1/2" stainless steel balls to fill it and 387 of my lead rods. Thats $266.00 for the SST and $189.00 for mine. D
bonehead99 Posted November 11, 2009 Posted November 11, 2009 (edited) I just built a small mill with a 4" jar for making BP. I have a lift bar in it now should I take it out? I'll be using 1/2 lead balls for my media and the jar turns at about 80RPM. I'd post pics of it but it's really ugly compared to the stuff you guys are making. Edited November 11, 2009 by bonehead99
Mumbles Posted November 12, 2009 Posted November 12, 2009 I'd say leave them in for now. They certainly can't hurt. You can usually tell by the sound. It should make a nice even cascading sound. If you are getting kind of an occasional slamming, you might want to remove them, or lower the RPM a bit.
bonehead99 Posted November 13, 2009 Posted November 13, 2009 (edited) Thanks for everyones help. I'm getting some stainless media from a friend soon so right now I'm not planning to use lead. Here's a video of my mill running without lift bar, it's nowhere near fully charged with media (maybe 80 1/2" lead balls) and has no material in it. Ball Mill Edited November 13, 2009 by bonehead99
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