stckmndn Posted June 26, 2011 Posted June 26, 2011 How much powder do you estimate you can mill at a time, cplmac? And how long do you think it will take?
cplmac Posted June 26, 2011 Posted June 26, 2011 In the video I posted it's got 50 pounds of potassium nitrate in the drum, I think it could easily mill 100 pounds, possibly 150. The mill time would totally depend on what I'm milling and the media I'm using but I don't plan on milling anything for longer than 10 hours. Bonny I started with a 1/3 HP motor, not nearly enough power, then the 2 HP motor was still short but definitely closer, the 5 HP motor I'm using now does the trick really well.
guntoteninfadel Posted June 27, 2011 Posted June 27, 2011 (edited) 50 pounds of potassium nitrate in the drum, I think it could easily mill 100 pounds, possibly 150 Kinda redefines the whole "go big or go home" thing now doesnt it. I fully understand the need for copious amounts of chemicals. I calculated today that I am needing 700+ one inch stars or 3500+ half inch stars just for the 10 mortar cans...... I really had no freaking idea. And this does not account for lift or breaking powder. My little quart sized ball mill is going to be really really tired before all this is over. Good news is I think I bought an appropriate motor today (ya know how reliable ebay is) and will start my build after the 4th. Edited June 27, 2011 by guntoteninfadel
cplmac Posted June 27, 2011 Posted June 27, 2011 (edited) I agree GTI, the little Thumblers model B just wasn't able to do what we needed anymore. Almost forgot, bought two racks of pool balls on ebay today and bid on a lot of 72 pool balls a few minutes ago. 100+ pool balls should be a really nice media in the new mill. Edited June 27, 2011 by cplmac
cogbarry Posted June 27, 2011 Posted June 27, 2011 I did the same thing after cooking the motor in my 3 lb harbor freight mill. I use one drum. I'm not filling it half way but do use more media than the 3 lb cap mill would take. I used to use airfloat (hardwood from skylighter) charcoal but have moved on to my own pine charcoal. I run it for a good 6 - 8 hours - not a problem, it's not like you need to attend it constantly. My BP is definitely more powerful than the commercial stuff. Granulating by moistening with dextrin and pushing through kitchen seive (about the same granularity of commercial 2g) produces a powder in which 20 grams will launch a baseball in the air for 11 - 12 seconds. I have a six pound double Harbor Freight mill. I run only one drum with 200, 50 caliber lead balls - these weigh 5 pounds and half fill the drum - and I mill half a pound of powder at a time (200-250g). With willow charcoal it makes powder as fast as Goex in three hours, and running it longer doesn't make it noticeably better. I don't think the size or quality of the mill matters as much as getting the quantity of media right - two drums with half the balls each doesn't work nearly so well. The single drum 3 pound model can't handle enough weight to do the job properly.
cplmac Posted June 27, 2011 Posted June 27, 2011 You'll need much more than 100 pool balls, no?I don't think so, but I won't know until I run it at that charge.
stckmndn Posted June 27, 2011 Posted June 27, 2011 I don't think so, but I won't know until I run it at that charge. I assume you're not going to be using the traditional 50% charge? Or would that just be much too heavy? BTW, I'm really enjoying following your project.
cplmac Posted June 28, 2011 Posted June 28, 2011 I assume you're not going to be using the traditional 50% charge? Or would that just be much too heavy?I think it would be too heavy, but I also don't think it's necessary.
pyrogeorge Posted January 6, 2012 Posted January 6, 2012 I forgot to share my ball mill in this topic. http://img52.imageshack.us/img52/4361/dsc02425nr.jpghttp://img17.imageshack.us/img17/3218/dsc02426m.jpghttp://img404.imageshack.us/img404/5330/dsc02427u.jpghttp://img703.imageshack.us/img703/5784/dsc02435ix.jpg I love my ball mill!I have perfect BP in 1.5hour!
marks265 Posted January 7, 2012 Posted January 7, 2012 PyroGeorge, Nice mill that you have made. There are two things that I would suggest changing. Threaded mill jars are considered to be an explosive hazard, so please come up with a different design. Second the small wheels at the end of the jar should be higher or lower so that they roll instead of rubbing in the center. What you have creates a much higher friction potential for heat. I once screened out some milled powder and found a nail in the screen. The nail had to be in my homemade charcoal. I guess one never knows when our number is up I guess. Mark
Col Posted January 7, 2012 Posted January 7, 2012 I don`t think a threaded jar should be any more hazardous than a non threaded. If the bp ignites, the jar will be in pieces whatever closure is used.
marks265 Posted January 7, 2012 Posted January 7, 2012 I don`t think a threaded jar should be any more hazardous than a non threaded. If the bp ignites, the jar will be in pieces whatever closure is used. I suppose your right, I wouldn't mind increasing the odds to calling attention to what I'm doing, losing all my media, and blowing up my mill either. At the very least ,anyways. Mark
californiapyro Posted January 7, 2012 Posted January 7, 2012 here's mine... total cost $5 for the home depot bucket. the rest is a free computer and treadmill from craigslist. the sawzall did the rest i guess about 6-8 hrs of labor http://www.youtube.com/watch?v=0z-IfQLQvmo
guntoteninfadel Posted January 7, 2012 Posted January 7, 2012 I don`t think a threaded jar should be any more hazardous than a non threaded. If the bp ignites, the jar will be in pieces whatever closure is used.I think the danger in the threaded jar comes from friction of opening and closing. Whereas no threads reduces friction.
Col Posted January 7, 2012 Posted January 7, 2012 I guess it depends on the type of jar, mine are hdpe with o-rings set in the lid so the bp can`t get to the threads. You`d have to be pretty unlucky to ignite the bp by unscrewing a plastic lid..although stranger things have probably happened http://i770.photobucket.com/albums/xx341/colinspyro/ballmillwithtwo1galjars.jpg
pyrogeorge Posted January 7, 2012 Posted January 7, 2012 PyroGeorge, Nice mill that you have made. There are two things that I would suggest changing. Threaded mill jars are considered to be an explosive hazard, so please come up with a different design. Second the small wheels at the end of the jar should be higher or lower so that they roll instead of rubbing in the center. What you have creates a much higher friction potential for heat. I once screened out some milled powder and found a nail in the screen. The nail had to be in my homemade charcoal. I guess one never knows when our number is up I guess. MarkDo you mean the danger when i open the jar?
marks265 Posted January 7, 2012 Posted January 7, 2012 Yes, that it is what I am referring to. The mechanical action of the threads during opening, closing, and milling of the mill jar. I have done this myself and I have chosen to stop using a jar with threads. It is a bit far fetched, but it is a possibility. I feel doing something like this teaches me complacency. If I can do a short cut here, where else can I cheat a little. All I hoped to accomplish here was remind people of the possibilities and the risks that we are taking. I can be a pretty bad gambler, even with good odds sometimes. By choosing not to gamble, I get to keep my money a bit longer.Also let us not forget that this is a good time of year for electric static discharge for some of us with dryer air.Be safe and cheersMark
dagabu Posted January 7, 2012 Posted January 7, 2012 I guess it depends on the type of jar, mine are hdpe with o-rings set in the lid so the bp can`t get to the threads. You`d have to be pretty unlucky to ignite the bp by unscrewing a plastic lid..although stranger things have probably happened I agree, the friction it takes to light off BP is quite high. I un-stick others tooling all the time and clean out the rammers as part of the operation and I have found that I can get whistle to pop when using the lathe to twist-pull rammers from the spindle but even at 200RPM, I have not been able to ignite BP when turning metal on metal with BP in between them. I don't use a twist on lid for my jars but as long as it is BP, I wouldn't miss any sleep over it. -dag
pyrogeorge Posted January 7, 2012 Posted January 7, 2012 Marks265,what type of jar do you use?can you share a photo please?
marks265 Posted January 7, 2012 Posted January 7, 2012 Marks265,what type of jar do you use?can you share a photo please? I started another blog and decided to make another jar for you from scratch with the steps that I take. I have pics of a used one but I decided to make a small tutorial in my blog which is in draft right now. Then I will have some part numbers and such to detail the blog hopefully. I will try to get it posted by the next 4-6 hours. Oh what the heck, for now it looks like this: Mark
marks265 Posted January 8, 2012 Posted January 8, 2012 (edited) For those who are interested I have added the 6" jar to my blog and it is live. I have been using these jars for many years and have not had a failure. I did drop a full jar once and it survived......so did I. edit to add link Blog found here: http://www.amateurpyro.com/forums/blog/14/entry-111-6-ball-mill-jar/ Mark Edited January 8, 2012 by marks265
Zmuro Posted January 8, 2012 Posted January 8, 2012 I guess it depends on the type of jar, mine are hdpe with o-rings set in the lid so the bp can`t get to the threads. You`d have to be pretty unlucky to ignite the bp by unscrewing a plastic lid..although stranger things have probably happened http://i770.photobucket.com/albums/xx341/colinspyro/ballmillwithtwo1galjars.jpg Where did you buy those jars? I'm looking for something similar, but a little bigger.
pyrogeorge Posted January 8, 2012 Posted January 8, 2012 Your opinion about these jars? http://www.curtec.com/en/products/conductive-drums/21 Zmuro check the other jars at home page..maybe you will find the jar you are looking for.
Recommended Posts