----------------------------------- Mircea Pteancu 03 Iul 2008 21:47 ----------------------------------- Salut neox pentru ca te vad incapatanat sa realizezi fapte marete pe taramul ATM,lucru care este foarte pe placul meu ,iata o solutie ,discutata de Mitchell R. et cie pe lista ATM: ............................................................................................ In the recent thread on parabolizing fast mirrors a lot of people mentioned ball milling rouge. I have some .3 micron black rouge, but when a small sample is left in water it is obvious some larger particles settle down. How does one go about building one of these simple ball millers? I take it you need a closed container, and it needs to spin with some heavy objects inside to break up the rouge. I have a bunch of marbles, could these work if the container is plastic so they wouldn't break? I suppose the truly simplest method would be to put some in a container with some metal balls and shake it like hell, but of course spinning it continuously for a few days is much easier on the arms, and more effective. Mitchell .............................................................................................. iar Jeff Row raspunde ,si sugereaza: Mitchell; There are alot of possibilities, IIRC in my research at the time, your spin rate has to be fast enough so the bearings fall, but not too fast, so they stick to the wall of your tumbler. I think mine spun about ~30 rpm. I would emphatically not use marbles, you'll shatter their surfaces and introduce glass dust into your product. I don't think you can tumble any old junk and hope to have a satisfactory product. I would suggest going down to a machine shop and asking them for their busted junk bearings on the floor, ( with the price of steel these days they might recycle everything : ( ). Maybe soak em in acetone to clean the oil off em. Robert C. suggested they used a variety of diameters at the Mirror Lab.IMHO let a machine mill this stuff, shaking is way too much work. I also saw bags of bearings on Ebay. I will send you a small movie file in my next email to you off list so you can see one in action. Best JR .............................................................................................. Curt Diggs adauga : Mitchell, I picked up a single cylinder rock tumbler from Harbor Freight back a couple of years ago for about $25, NAICR. The container is plenty big enough. These things work fine but the rubber drive belt will break eventually. Ping me off-list if you decide to go this route and I'll mail you a replacement belt or two. I picked up a bag of O-rings of exactly the same size that work fine as a replacement. I got enough to last a couple of lifetimes for a few bucks. I also picked up a pack of steel ball bearings from somewhere (Home Depot or maybe Ace Hardware) of about 1/2" dia. but I don't think size is critical. You can order these on-line from several places like McMaster-Carr. Stainless steel is probably best but just don't use chrome-plated balls (it'll flake off). Curt Diggs .............................................................................................. George Blahun Jr. completeaza: Mitchell: I recently ball milled some black rouge I received from Got Grit. I used a rubber drummed rock tumbler and some stainless steel ball bearings and let it run for two weeks. After straining the material I used the technique in Texereau and poured filtered water into the beaker with the rouge mixture and carefully poured off the upper layer of water and stray particles. After a dozen or so cycles, I was left with a uniformly thick layer of rouge and practically no stray floating particles. George ................................................................................................ neox insa ce zice ? se pare ca problema este rezolvabila.Mircea