Powderman Posted March 30, 2021 Posted March 30, 2021 I would like to know if someone successfully made very small ball mill for milling samples like 5 to 10 grams. From what I learned so far, I is not a good idea to grind 5g of material in standard sized ball mill. It requires proper fill to work. I should mention that the samples would have no big particles. I can make 5 grams with mortar and pestle, but it is too much time and labor...
ChrisPer Posted March 30, 2021 Posted March 30, 2021 (edited) My newbie experience has not been encouraging for using small amounts; the 5g of material would end up as a fine coating caked on the balls and be difficult to recover! The tiny rock tumblers I decided to avoid (eg from National Geographic) might be suitable but I think you would want to go to a bit larger cylinder media to make it easier to clean the material out. A good tool might be a tungsten ring and puck mill as used in analytical laboratories for pulverising rock samples. They certainly do a great job fast, and easily give up all the material before being cleaned by a blow-out with compressed air. However, I have no idea how to implement this at a reasonable cost for a hobbyist. This webpage shows three sizes of machines, down to 1-10g of sample in the smallest: http://minerva.union.edu/hollochk/ringmill/index.html Also, click the link for hydraulic crusher, that looks like a great rocket press!http://minerva.union.edu/hollochk/crusher/index.html Edited March 31, 2021 by ChrisPer
BasedAndRocketpilled Posted March 31, 2021 Posted March 31, 2021 Any reason for shying away from a cheap blade mill?
BasedAndRocketpilled Posted March 31, 2021 Posted March 31, 2021 Small coffee grinder. Perfect for small quantities of chems. This is the one I use for oxidizers and bentonite. https://www.amazon.com/Hamilton-Beach-Coffee-Grinder-80335R/dp/B005EPRFKO/ref=mp_s_a_1_3?dchild=1&keywords=coffee+grinder&qid=1617154489&sprefix=blade+mill&sr=8-3
SharkWhisperer Posted March 31, 2021 Posted March 31, 2021 I would like to know if someone successfully made very small ball mill for milling samples like 5 to 10 grams. From what I learned so far, I is not a good idea to grind 5g of material in standard sized ball mill. It requires proper fill to work. I should mention that the samples would have no big particles. I can make 5 grams with mortar and pestle, but it is too much time and labor...I have never met one individual in my life, until now, who has ever considered attempting to ball mill 5-10 g of anything. Not trying to be a dick, but just....why????
Richtee Posted March 31, 2021 Posted March 31, 2021 Small coffee grinder. Perfect for small quantities of chems. I don’t think a blade mill will give the results of a ball. But,,,I do not know the OP’s purpose.
ChrisPer Posted March 31, 2021 Posted March 31, 2021 Small coffee grinder. Perfect for small quantities of chems. This is the one I use for oxidizers and bentonite. https://www.amazon.com/Hamilton-Beach-Coffee-Grinder-80335R/dp/B005EPRFKO/ref=mp_s_a_1_3?dchild=1&keywords=coffee+grinder&qid=1617154489&sprefix=blade+mill&sr=8-3Oooooh, I use one of these to get everything down below 100mesh, before incorporation in a ball mill. I have read very persuasive advise never to use it for incorporating the chemicals. So I do not.
Powderman Posted March 31, 2021 Author Posted March 31, 2021 My newbie experience has not been encouraging for using small amounts; the 5g of material would end up as a fine coating caked on the balls and be difficult to recover! The tiny rock tumblers I decided to avoid (eg from National Geographic) might be suitable but I think you would want to go to a bit larger cylinder media to make it easier to clean the material out. A good tool might be a tungsten ring and puck mill as used in analytical laboratories for pulverising rock samples. They certainly do a great job fast, and easily give up all the material before being cleaned by a blow-out with compressed air. However, I have no idea how to implement this at a reasonable cost for a hobbyist. This webpage shows three sizes of machines, down to 1-10g of sample in the smallest: http://minerva.union.edu/hollochk/ringmill/index.html Also, click the link for hydraulic crusher, that looks like a great rocket press!http://minerva.union.edu/hollochk/crusher/index.htmlThank You for Your insight, now I have more options to consider and better understanding of problems with small amounts of material in ball mills. I forgot to mention that it would be nice if the mill was BP compatible. I was thinking about having very slim bal mill, something two to three times the ball diameter, or if I can find it use cylinder media in one row only... Mill diameter I suppose should be at least 10cm / 4"...
Powderman Posted March 31, 2021 Author Posted March 31, 2021 Any reason for shying away from a cheap blade mill?I am using coffe grinder and big blender at the time for pre-milling. But I need something to finish the milling to ball-mill spec and make it safely with combined ingredients (BP for instance). I am using blender/grinder only for one chem at a time.
Powderman Posted March 31, 2021 Author Posted March 31, 2021 I have never met one individual in my life, until now, who has ever considered attempting to ball mill 5-10 g of anything. Not trying to be a dick, but just....why????Because I am playing with various compositions and it is definitely safer and cheaper to use only small quantities. When I sort out what suits my needs and/or the joy of research fades away, I will probably step up to normal quantities.
BasedAndRocketpilled Posted March 31, 2021 Posted March 31, 2021 (edited) Because I am playing with various compositions and it is definitely safer and cheaper to use only small quantities. When I sort out what suits my needs and/or the joy of research fades away, I will probably step up to normal quantities.One thing you should definitely consider is that as your scale of production decreases the margin for error increases proportionally. +-1g of a chem in a 100g batch will be fairly negligible, while the same gram can drastically alter the properties of a 10g batch. Edited March 31, 2021 by BasedAndRocketpilled 1
Powderman Posted March 31, 2021 Author Posted March 31, 2021 My scales go to 0,01g and I am skilled at working with small quantities.
Arthur Posted March 31, 2021 Posted March 31, 2021 The cost of a specialist mill for one purpose only may horrify you, or the time taken to make one. Realistically a commercial rock tumbler of the smallest size available could be useful. If I really had to make something I'd be looking at a drum 4 to 6 inches diameter and ONLY about 0.375 to 0.5 inches long. I'd then be looking for some roller bearings to be carefully placed in about half of the drum volume in one layer. With all the design and machining time the mill would cost hundreds and still probably need 50g inside to make it work. 1
Powderman Posted March 31, 2021 Author Posted March 31, 2021 (edited) Hmm... Would shaking in small container with small balls work? Force is greater than in free falling device... And could be easy and cheap to do... There must be way :-)Media also comes really cheap:https://www.ebay.com/itm/5mm-50PCS-Brass-H62-Solid-Bearing-Balls-High-Precision/322264446074 Edited March 31, 2021 by Powderman
justvisiting Posted March 31, 2021 Posted March 31, 2021 There is a way. I don't know how safe it would be, but pharmacists use ceramic tiles for grinding and compounding. You might look into that.
Richtee Posted March 31, 2021 Posted March 31, 2021 Hmm... Would shaking in small container with small balls work? Force is greater than in free falling device... And could be easy and cheap to do... There must be way :-) Well, sure. IF you got nothing to do for 5 or 6 hours....
Powderman Posted April 1, 2021 Author Posted April 1, 2021 Motor will do it for me, motorized solution is what I am looking for... This part should not be an issue.
24pyro97 Posted April 2, 2021 Posted April 2, 2021 i have a normal sized ball mill for when im actually milling large amounts of composition. and for things like testing star comps and etc. i usually make about ten grams and i have a small pvc pipe that i add my media into to mill it ( if i need to). if I don't I just use a blade mill coffee grinder and blended some of the components separately and that gives me a good idea of what the comp will look like.
Powderman Posted April 3, 2021 Author Posted April 3, 2021 i have a normal sized ball mill for when im actually milling large amounts of composition. and for things like testing star comps and etc. i usually make about ten grams and i have a small pvc pipe that i add my media into to mill it ( if i need to). if I don't I just use a blade mill coffee grinder and blended some of the components separately and that gives me a good idea of what the comp will look like.Interesting idea, what dimensions is your PVC tube? Do I understand it correctly that it is inserted to empty ball mill to roll inside? What is your media size?
SharkWhisperer Posted April 5, 2021 Posted April 5, 2021 (edited) Interesting idea, what dimensions is your PVC tube? Do I understand it correctly that it is inserted to empty ball mill to roll inside? What is your media size?That's not milling. That's just the lazy man's way of shaking things together in a jar, and will give the same incorporation/results, i.e., minimal improvement and nothing like actual milling. You'd probably be just as well off, or better, screen-mixing your comp. I cannot envision a composition that you cannot afford to make 100g of (not 5 or 10 g) in a small ball mill, doing actual milling if required. Diamond dust? Platinum powder? The most expensive chem you're talking about is titanium for $15-18/lb (unless you're getting ripped off from SkyRobber) or bismuth trioxide for $20/lb. Often cheaper if you look around, at least in the US. And I hope you're not milling Ti except alone, certainly not with any oxidizer... Edited April 5, 2021 by SharkWhisperer
Powderman Posted April 9, 2021 Author Posted April 9, 2021 It is not that I can not afford it, it is just unreasonable to make 100g batch only to find out it is no good... Making small batches is safer, cheaper, cleaner... Sometimes I test 5 or more slightly different compositions in a day... There are so many combinations and ratios to try... Seeing how it performs and how the ratios change its properties is very interesting and educational for me. And sometimes I need as little as 0,1g to know its properties. Then I have to find some fun way to spend remaining 4,9g... I live in the EU by the way... Huge ban on all kinds of useful chemicals came in to action 1.2.2021 here, so my comeback to (pyro)chemistry gets quite complicated... So another reason not to waste supplies...
Arthur Posted April 9, 2021 Posted April 9, 2021 I understand the/your desire to make a small mill. Most of the rules of thumb for mills refer only to diameter, so you'd be as well to make a jar the same diameter that you usually use but far shorter. You could look at making a mill 100mm or 150mm diameter and only say 10 to 15mm long, maybe you'd have to make it inside a longer piece of pipe. Use steel or lead or ceramic cylinder media (Cylpebs come to mind as do bearing rollers). However not everything in pyro scales up and down well. You'd have to do tests to confirm that a batch tested at 50g scaled well to 500g. 1
BetICouldMake1 Posted April 11, 2021 Posted April 11, 2021 I understand the desire to experiment with small batches, though I really can't think of many things that could be tested in a meaningful with only a 5g sample. Seriously. 5g is the mess I wipe off into the burn bucket when I'm done building. That aside, there are very few compositions that are ball milled as a complete mix apart from black powder and a handful of charcoal streamers. Why not screen mix your test comps?
Powderman Posted April 11, 2021 Author Posted April 11, 2021 That makes sense... I was thinking the same as possible solution, diameter is needed for the mill to work, but it can be short. At the moment I am able to buy relatively cheap stainless steel 12mm balls, I am thinking to buy some to try it. I could scale it to work for maybe 50-100g batches, so at least I could mill separate ingredients in reasonable amounts and then use mortar and pestle to combine. And I am thinking how daring woud it be to mill my sulfurless BP with SS media. Composition is KNO3, charcoal and sugar containing 3% Fe2O3 (66/29/5). It granulates well with 25% isopropyl and burns good. Absence of sulfur seems to make it more inert compared to standard BP.
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