cplmac Posted June 21, 2011 Share Posted June 21, 2011 Almost done with the big mill, here are a few pics I took tonight after mounting the sprockets and half the chains, also some pics from painting. Frame extensions welded upprepped for paintnew sprockets installedhalf the chains installed Link to comment Share on other sites More sharing options...
Bonny Posted June 21, 2011 Share Posted June 21, 2011 Almost done with the big mill, here are a few pics I took tonight after mounting the sprockets and half the chains, also some pics from painting. That's a lot of chain!! What size are you using??I'm not sure I understand why so many chain attachments, speed selections? Link to comment Share on other sites More sharing options...
cplmac Posted June 21, 2011 Share Posted June 21, 2011 The chain is #60, I have to do a lot of gear reduction so I have to use a lot of sprockets. I am reducing speed from the motor output of 3400rpm to 180rpm. Link to comment Share on other sites More sharing options...
oldguy Posted June 21, 2011 Share Posted June 21, 2011 Why use sprockets & chain?Isn't that costly?2 pulleys & a belt with an idler arm to adjust belt tension is toilet flush simple. Link to comment Share on other sites More sharing options...
PersonGuyDude Posted June 21, 2011 Share Posted June 21, 2011 Why use sprockets & chain?Isn't that costly?2 pulleys & a belt with an idler arm to adjust belt tension is toilet flush simple. Geez that thing is a beast. I've been avoiding ball mills because I am now trying to do all my manufacturing at club events. I always figured that 3 days is not long enough to ball mill any substantial amount of anything and have it wetted and dried in time to assemble. However, it seems that people who build their own mills can mill good BP in like 2-4 hours, damn! Guess I am gonna have to get that book about Ball Mills, authored by Lloyd something or other... Link to comment Share on other sites More sharing options...
dagabu Posted June 21, 2011 Share Posted June 21, 2011 Geez that thing is a beast. I've been avoiding ball mills because I am now trying to do all my manufacturing at club events. I always figured that 3 days is not long enough to ball mill any substantial amount of anything and have it wetted and dried in time to assemble. However, it seems that people who build their own mills can mill good BP in like 2-4 hours, damn! Guess I am gonna have to get that book about Ball Mills, authored by Lloyd something or other... Lloyd Sponenburgh http://www.fireworksnews.com/product/54/2 -dag Link to comment Share on other sites More sharing options...
PersonGuyDude Posted June 21, 2011 Share Posted June 21, 2011 Lloyd Sponenburgh http://www.fireworks...om/product/54/2 -dag Wow your a fast one Dag. I can see what you mean by having to stay inside when all you want to do is making something, can't wait till I can GTFO of this nanny state. Oregon is close enough, and I've heard that the firework laws are... Decent there. Link to comment Share on other sites More sharing options...
oldguy Posted June 21, 2011 Share Posted June 21, 2011 Zirc M media In a rubber HF jar with Zirc M media I can finish perfect BP in 90 minutes. With a PVC jar on the beast about 80 minutes. The BEAST with a big pvc jar & Zirc M media will do 5 + lbs of about anything (even prill) in 100 minutes. Exception is 50/50 mg/al to about air float size, which takes slightly longer. Link to comment Share on other sites More sharing options...
stckmndn Posted June 21, 2011 Share Posted June 21, 2011 I love my Zirc M media. Thanks again for the ebay link, oldguy! And PGD, check out the MJR 15lb Cap Tumbler in the Ball Milling FAQ thread. You can't go wrong. Sure, it might seem a little expensive but it's worth every penny and will save you the expense of buying the book. With two HF rubber jars and lead media you can mill your powder in 2 1/2 to 3 hours. With the Zirc M media the time is cut down to 1 1/2 hours. Link to comment Share on other sites More sharing options...
moondogman Posted June 21, 2011 Share Posted June 21, 2011 (edited) Old Guy Got any of that airfloat mgal for sale 1/2 lb would be great.Steve Edited June 21, 2011 by moondogman Link to comment Share on other sites More sharing options...
cplmac Posted June 22, 2011 Share Posted June 22, 2011 Why use sprockets & chain?Isn't that costly?2 pulleys & a belt with an idler arm to adjust belt tension is toilet flush simple.It is ridiculously costly, and I'm using sprockets for a couple of reasons. First I have to reduce the motor speed almost 19:1 which will take several pulley reductions to achieve. Second I'm turning between 50-150 pounds with a 5 horse motor, that takes positive traction which I don't think I can achieve with a V-belt. However, I got the last chain on this evening and fired it up and there is definitely a problem. The motor is turning so fast that the chain is spitting off all the oil and grease and running very hot. I'm not sure if the chain will break if used for prolonged periods of time, but I'm considering using a timing belt and timing belt pulleys because they are built to run at high speed. The real main problem is that I'm using a motor that is just too damn fast. I really wish I had three phase, I'm considering switching the whole damn thing to hydraulic. Link to comment Share on other sites More sharing options...
oldguy Posted June 22, 2011 Share Posted June 22, 2011 Old Guy Got any of that airfloat mgal for sale 1/2 lb would be great.Steve Using up all I have & make.Try hobbychemicalsupply, they have decent proces. Link to comment Share on other sites More sharing options...
cplmac Posted June 22, 2011 Share Posted June 22, 2011 Just about done, couple of bugs to work out. Link to comment Share on other sites More sharing options...
vladou Posted June 22, 2011 Share Posted June 22, 2011 I bought a 12lbs rock tumbler (Star Diamond) on ebay. It is from the 70's and has a 20x20cm rubber barrel. The problem is that it runs only at 26 rpm and should normaly run at 96rpm with 2cm glass media right? I can put some tape arround axes to make them bigger but won't the motor burn out? Link to comment Share on other sites More sharing options...
dagabu Posted June 22, 2011 Share Posted June 22, 2011 I bought a 12lbs rock tumbler (Star Diamond) on ebay. It is from the 70's and has a 20x20cm rubber barrel. The problem is that it runs only at 26 rpm and should normaly run at 96rpm with 2cm glass media right? I can put some tape arround axes to make them bigger but won't the motor burn out? I suggest that you get rid of the glass media, it is inefficient and will chip off into your comp. I dont think that tape is a good idea, it will debond, unravel, get sticky, give uneven support or foul the barrel and roller. I suggest that you use radiator hose to build the size of the rollers up. It is much stronger and it is smooth but made from rubber so it will grip the roller and the barrel. Keep an eye on the temp of your motor, if it is too hot to touch, you are working it too hard but keep in mind that if the motor is from the 70s, the motor may not last long in any case. -dag Link to comment Share on other sites More sharing options...
vladou Posted June 22, 2011 Share Posted June 22, 2011 Thank's for your answer. So I definitely won't be able to make hot BP at 26rpm? But if I had more media (let say about 75% of the barrel's capacity) it could be more efficient couldn't it? Link to comment Share on other sites More sharing options...
dagabu Posted June 22, 2011 Share Posted June 22, 2011 Thank's for your answer. So I definitely won't be able to make hot BP at 26rpm? But if I had more media (let say about 75% of the barrel's capacity) it could be more efficient couldn't it? No, 75% would actually reduce the efficiency of the ballmill. Lloyd Sponenburgh has written the book (literally) on the subject, and depending on the media and the chemical(s), the best efficiency is achieved at around 50% media and fill the jar with comp to just cover the media. BALL MILLS -dag Link to comment Share on other sites More sharing options...
vladou Posted June 22, 2011 Share Posted June 22, 2011 Why? If the speed is too low, I suppose we need to put more media to make a better cascading effect. Am I wrong? Link to comment Share on other sites More sharing options...
dagabu Posted June 22, 2011 Share Posted June 22, 2011 Why? If the speed is too low, I suppose we need to put more media to make a better cascading effect. Am I wrong? All things considered, having the correct load of media and chems is better then the correct speed of rotation. If there is not enough media to cascade correctly, the efficiency will suffer dramatically as the media will often just slide along the bottom of the jar. If the jar is under loaded with the comp, there is speculation that there is not enough cushioning and the comp can be pinched enough to cause a runaway ignition. I suggest that you read Lloyds book, it will answer all of your questions. -dag Link to comment Share on other sites More sharing options...
vladou Posted June 23, 2011 Share Posted June 23, 2011 (edited) Ok, I see. Maybe it could be a good idea to put some bars to retain the media and therefore make a bigger cascade like in this picture? http://img204.imageshack.us/img204/7296/bm7o.jpg Uploaded with ImageShack.us Edited June 23, 2011 by vladou Link to comment Share on other sites More sharing options...
dagabu Posted June 23, 2011 Share Posted June 23, 2011 Ok, I see. Maybe it could be a good idea to put some bars to retain the media and therefore make a bigger cascade like in this picture? http://img204.imageshack.us/img204/7296/bm7o.jpg Uploaded with ImageShack.us There have been suggestions that a ball mill explosion two years ago was caused by lifter bars and an undercharged ball mill jar. BP ignites at 300 C (572° F) and it is said that a ball traveling fast enough within the ball mill jar all alone and not cascading down in a group may pinch fine BP dust hard enough to cause enough friction to cause ignition. This may very well be all BS, I do not know but I personally will not use lifters for that very reason. Now... lifters in a jar that is used for single chems? Expect high wear on your media but from a safety standpoint, I see no real hazard, after all the ball mill is outside and in a barricade right? -dag Link to comment Share on other sites More sharing options...
vladou Posted June 23, 2011 Share Posted June 23, 2011 Ok thank you for your help. Of course I don't want my ball mill explodes. For that reason, I won't make any modification but just mill my BP longer as BJV told me. Link to comment Share on other sites More sharing options...
Bonny Posted June 23, 2011 Share Posted June 23, 2011 The chain is #60, I have to do a lot of gear reduction so I have to use a lot of sprockets. I am reducing speed from the motor output of 3400rpm to 180rpm. #60 chain is pretty heavy even for the drum size. It is ridiculously costly, and I'm using sprockets for a couple of reasons. First I have to reduce the motor speed almost 19:1 which will take several pulley reductions to achieve. Second I'm turning between 50-150 pounds with a 5 horse motor, that takes positive traction which I don't think I can achieve with a V-belt. However, I got the last chain on this evening and fired it up and there is definitely a problem. The motor is turning so fast that the chain is spitting off all the oil and grease and running very hot. I'm not sure if the chain will break if used for prolonged periods of time, but I'm considering using a timing belt and timing belt pulleys because they are built to run at high speed. The real main problem is that I'm using a motor that is just too damn fast. I really wish I had three phase, I'm considering switching the whole damn thing to hydraulic. The speed looks pretty fast, watch your fingers! I doubt the chain will break anytime soon unless it gets very hot. Why not look for a slower motor, or a DC motor so you can reduce the speed. It would also reduce the number of sprockets needed, thus lowering the power used by all the sprockets and chains. Link to comment Share on other sites More sharing options...
cplmac Posted June 24, 2011 Share Posted June 24, 2011 The number 60 chain is definitely overkill, but at least I don't have to worry about the chain being the weak link, plus it looks pretty cool. The speed on the first sprocket is very fast, I did the math and it's traveling at about 2500 feet per minute. The only slower motor with the power I needed was 3 phase and I don't have three phase. I had to run a 240 line just to get this motor running. I did some thorough testing tonight, and after 2.5 hours of running a 50 pound nitrate load with 500 golf balls the chain was maintaining it's temperature at 220 degrees. The motor was maintaining 175 degrees, the primary drive sprocket was running at 130 degrees and every other chain and sprocket was under 110 degrees. If 220 is as hot as it gets then I'm not worried and I'll run it as is. The next big issue is where to set it up, the thing is damn loud. I might set a small fan up in front of the motor where the chain is the hottest to try and cool the chain and motor just a little bit. Unfortunately the motor's internal fan pulls it's air directly from where that chain is, either way the motor is thermally protected so I'm not worried. Link to comment Share on other sites More sharing options...
Bonny Posted June 24, 2011 Share Posted June 24, 2011 The number 60 chain is definitely overkill, but at least I don't have to worry about the chain being the weak link, plus it looks pretty cool. The speed on the first sprocket is very fast, I did the math and it's traveling at about 2500 feet per minute. The only slower motor with the power I needed was 3 phase and I don't have three phase. I had to run a 240 line just to get this motor running. I did some thorough testing tonight, and after 2.5 hours of running a 50 pound nitrate load with 500 golf balls the chain was maintaining it's temperature at 220 degrees. The motor was maintaining 175 degrees, the primary drive sprocket was running at 130 degrees and every other chain and sprocket was under 110 degrees. If 220 is as hot as it gets then I'm not worried and I'll run it as is. The next big issue is where to set it up, the thing is damn loud. I might set a small fan up in front of the motor where the chain is the hottest to try and cool the chain and motor just a little bit. Unfortunately the motor's internal fan pulls it's air directly from where that chain is, either way the motor is thermally protected so I'm not worried. Based on the amount of gear reduction, I think you could proabably get away with a lower HP motor. I remember reading that everyone recommends 1/4- 1/2hp on standard hobby size ballmills. I ran mine with 1/15 HP for years. The only reason I switched was because I got a reversible motor. Link to comment Share on other sites More sharing options...
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