calebkessinger Posted July 14, 2015 Share Posted July 14, 2015 (edited) Nah.. the base / bearings , motor bracket, and rollers are just under 100 bucks delivered to my door. barrel is the same. Takes me a few hours to make and mount all the parts, - rollers, new motor, pulley, cord. Then you have a mill that is bulletproof and you can get replacement parts very easily if needed. The base/motor assembly only weighs 12 lbs I think. easy to move and use. look how simple it all is. Edited July 14, 2015 by calebkessinger Link to comment Share on other sites More sharing options...
Merlin Posted July 14, 2015 Share Posted July 14, 2015 CalebWish I had known you modified these things. I just got a 40 lb MJR yesterday. Link to comment Share on other sites More sharing options...
starxplor Posted July 15, 2015 Share Posted July 15, 2015 I guess I will just have to wait until I start milling to truely understand, heh. Nice pic though, it does look sleak. Link to comment Share on other sites More sharing options...
jakespeed Posted May 9, 2016 Share Posted May 9, 2016 First post. I have a Frankford Arsenal Rotary Tumbler that I use for cleaning reloading brass (works great). It has a seven liter rubber lined drum, is direct drive and rated at 30 pounds capacity. The drum has a six sided design. I thought I would try it out as a ball mill, so I cast up a large batch of .575" (58 cal) hard round lead balls. The trouble is that 30 pounds of lead balls only fills it to about 1/3 full. I know that it is desirable to have the mill 1/2 full of media. Will I get acceptable efficiency with only 1/3 of the mill full of media? Should I try to find brass instead? http://www.btibrands.com/product/platinum-series-rotary-tumbler-7l/ how well does your Frankford work ? does anyone else run a Frankford Arsenal ? wondering how the rubber lining affects the crushing of the material Link to comment Share on other sites More sharing options...
OldMarine Posted May 10, 2016 Share Posted May 10, 2016 (edited) how well does your Frankford work ? does anyone else run a Frankford Arsenal ? wondering how the rubber lining affects the crushing of the material Ned Gorski (ala Skylighter and fireworking.com) swears by the hexagonal rubber lined jars. He says it virtually eliminates clumping. Edited May 10, 2016 by OldMarine Link to comment Share on other sites More sharing options...
Mumbles Posted May 10, 2016 Share Posted May 10, 2016 Is Ned talking about the metal jars that are lined with rubber, or the hex jars that are all rubber? It may not matter, just curious. Link to comment Share on other sites More sharing options...
OldMarine Posted May 10, 2016 Share Posted May 10, 2016 (edited) I forget the brand name but they're metal with a rubber insert. They have thumbscrew lids. Ned posted a link in his article:http://www.therockshed.com/tumbler2.html#Parts I'm thinking the bounce between the can and rubber liner causes enough flex to pop powder off the wall and stop the clumping. Edited May 10, 2016 by OldMarine Link to comment Share on other sites More sharing options...
Merlin Posted May 10, 2016 Share Posted May 10, 2016 I have had clumping in the Sponnenbrough 40 lb MJR setup but this was eliminated by drying Chems prior to milling and limiting milling time to what is optimal about 3 hrs.I never had clumping in the hex flats type rubber. I can run two one gallon jars on the MJR at 60 rpm rather than the lortone. Either way it works well as long as the RPM is around 60. Link to comment Share on other sites More sharing options...
Arthur Posted May 10, 2016 Share Posted May 10, 2016 Hex jars work, rubber lined jars work, even round 100% rubber jars work, you may have to adjust the time. Most if not all "tumblers" will fail to turn optimally loaded with lead balls, either you work with fewer balls or you chose brass or ceramic media. Rubber (lined or solid) drums absorb much of the mill noise which makes life much more civilised and neighbour friendly. Clumping in my experience has been entirely caused by milling moist ingredients. Start by drying the ingredients for a good while separately paying particular attention to the charcoal. remember that if you weigh out damp ingredients the final product will not be what you expect as the water will dry out of the weighed materials. Ingredients dry for an hour separately at 100+ C (200+ F) Mixtures dry gently not exceeding 30c for a long time, dry to the point of constant weight. Link to comment Share on other sites More sharing options...
vtbassmaster Posted June 17, 2016 Share Posted June 17, 2016 I have been searching the forum for a comprehensive set of plans for DIY ball mill like Old Guy's? Maybe either a 6" or 8" diameter. I am looking for the HP rating, pulley sizes and the size and quantity of lead media. Seems like this is probably out there and I am just not seeing it. I find parts and pieces of the information but it would be nice if it was all in one spot. Thanks! Lou Link to comment Share on other sites More sharing options...
otto Posted June 17, 2016 Share Posted June 17, 2016 (edited) @ Lou: It sounds easy but it's more complicated than that. First you need to decide 6" or 8" and determine your motors RPM. I think OG was using a 1/2 HP on that rig. I can turn 3 of the large Thumblers style hex jars with a 1/3 HP but I'm driving both shafts. That's the next thing is the diameter of your driving shaft (axle / roller) as that is part of the equation to getting to your optimum jar RPM. From all that you can then calculate your necessary pulley sizes. I'd suggest a copy of the ball milling bible: "Ball Milling Theory and Practice for the Amateur Pyrotechnician" written by some Lloyd guy........ That would tell you everything you need to know to get started and more. Edit: As I think about it, you should start at page 67 and read to the end. I think about this and other experiences I have read on this forum frequently. In my other hobbies I am always mindful of legislated limits because I want to stay on this side of keeping it fun. In this hobby we have to police ourselves to insure our safety (and keep it on the fun side). Thanks Lloyd (and Dave and Burrito Bandito)! Edited June 17, 2016 by otto Link to comment Share on other sites More sharing options...
vtbassmaster Posted June 20, 2016 Share Posted June 20, 2016 Thank you Pyromaniac. I am heading over to the local piping place to see what I can pick up reasonably for some short pieces. I have some 6 pvc already but would like to build it with 8". I am an engineer, so I can easily figure the pulley ratios. This is a new hobby for me and I would rather build a machine that can turn out the amount of BP in a shorter amount of time so that I am not constantly having to set up the bunker for protection. I will pick up a copy of Lloyd's book. Is there another source for those rubber lined hex barrels? $90 each seems kinda steep. Link to comment Share on other sites More sharing options...
memo Posted June 20, 2016 Share Posted June 20, 2016 vtbassmaster.you really need a bunker of some kind, just in case... sand bags work. memo Link to comment Share on other sites More sharing options...
OldMarine Posted June 21, 2016 Share Posted June 21, 2016 At my mill site I've got a fiberglass bathtub buried to within an inch of the rim with a sloping wall of sandbags. If it looks like rain I'll toss a couple of 4x4s across it with a sheet of plywood and more sandbags. After heaving those roof bags once, I started looking more closely at the forecast! Link to comment Share on other sites More sharing options...
FelixLiu Posted June 24, 2016 Share Posted June 24, 2016 This is worth considering Link to comment Share on other sites More sharing options...
pyronoob Posted August 8, 2016 Share Posted August 8, 2016 Im gonna upgrade to an MJR 15# mill from a HF 6#....my question is i can mill 200 grams in my HF jar....what is the charge weight of the MJR?? Link to comment Share on other sites More sharing options...
Merlin Posted August 9, 2016 Share Posted August 9, 2016 I run a 40# MJR with 30 lbs lead and mill 2.5 lbs of BP. Maybe that will give you an idea. My jar may not be optimized but I dont want to overload it. Im guessing you could run 10-12 lbs lead and mill 1 lb BP. Link to comment Share on other sites More sharing options...
pyronoob Posted August 9, 2016 Share Posted August 9, 2016 Thanks Merlin....The way i understand it i should be able to increase my jar size later without having to buy a new mill. I hope to be able to run the same amount as you. Link to comment Share on other sites More sharing options...
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