635 replies to this topic

[italteen3]

I got mine at UN and it is true, the drum is considerably less than half full of media.
There is enough to mill 100g or so of most powders, but you'll likely want more.

Harbor Freight sells the same model much cheaper (half-ish, wish I knew then...), I believe it comes with no media, but if you were getting more anyhow-cheaper mill, same brand
Don't know if they ship to U.K.

Yeah I purchased the dual drum rotary tumbler from Harbor Freight for a fraction of the cost and am very satisfied cost wise. On the other hand the barrels can only hold 3 lbs and since 50 1/2" lead media's fill only an 1/8 of the jar thats not good. Considering each media is about 12 grams if I fill the jar 1/4 the way thats already almost 3 pounds and leaves enough for a very small batch.

So hopefully brass media weighs much less and can fill in the void. Does anyone happen to know how much a 1/2" cylindrical piece of solid brass weighs(approximately)?

If anyone does deside on getting the chicago electric tumbler, also the one found at United Nuclear and Harbor Freight, it does tend to get hot near the plate next to the motor where the switch is. The heat is shielded by another metal plate. I have only run it for 6 hours straight the most and did not notice any heat on the jars themselves but I always gave atleast 15 minute cool time before another running. Cant hurt to be too careful. I will also be installing a fan in the table and run the tumbler secured over the fan so it cools the engine better then the small fan.

[paul]

Brass wights ca. 8,5 g/cm?. So if you use a length of 1/2" and a diametre of 1/2" it would weight ca. 3,4g


paul

Edited by paul, 18 July 2004 - 11:48 AM.

[RegimentalPyro]

0.5" diam cylinder is 1.27 cm

Therefore radius is 0.635cm

Volume = PI.r.r.h
Volume = 3.141 x 0.635 x 0.635 x 1.27 = 1.608 cc

Density = 8.5g / cc
Therefore weight of brass cylinder 0.5" x 0.5" = 8.5 x 1.608 = 13.66g

[The_Djinn]

That sounds better, thought 3.4g sounded a bit light for brass .5 x .5

Mark

Edited by The_Djinn, 19 July 2004 - 09:30 AM.

[paul]

Jepp I found my mistake. A very stupid one. My calculation was "8,5g / ...." and not "8,5g * ..."

Sorry

[pyrotechnist]

I am thinking of building an old time gunpowder-milling machine with weights, which you use for doing weight lifting it will give better mixes and they are very heavy, most likely. I will use very heavy weights for it and with a powerful motor. Is this a good idea? Can these also do other chemicals like sulphur, perchlorate, charcoal, red gum, magnesium, potassium nitrate ect ect ? Thanks.

Michael

Edited by pyrotechnist, 21 July 2004 - 12:02 PM.

[miniskinny]

Wow...I had no idea that chlorates are so crappy. Hm. Well, I'll stop making gunpowder with chlorates then ....That's why they call us novices.

[Richard H]

I've said this time and time again, but I really recommend you get some good books and read, read, and read! I spent a couple of years researching the subject before I did any small experiments, and I'm glad I did.

There is much to learn, chemical compatibilities perhaps being the most crucial to your future prosperity and chances of survival. Making chlorate blackpowder is a bit like playing Russian Roulette, you might get away with it a few times but you can bet that something really bad will happen eventually.

Be careful. Please.

[pyrotechnist]

I am thinking of building an old time gunpowder-milling machine with weights, which you use for doing weight lifting it will give better mixes and they are very heavy, most likely. I will use very heavy weights for it and with a powerful motor. Is this a good idea? Can these also do other chemicals like sulphur, perchlorate, charcoal, red gum, magnesium, potassium nitrate ect ect ? Thanks.

Pleas i need help .

[Richard H]

I think you are going to find it very difficult. Put it this way, my ball mill is just fine, and the blackpowder it produces is equal, if not better than european commercial powders that I have made comparisons with.

[lord_dranack]

If you are sitll interested I could scan in some plates showing the old type of mill from a reprint of an 18th century french book on cannon making I managed to get today.
It also has a section on fireworks and rockets, with some quite wacky looking designs.

[pyrotechnist]

Ok lord dranack i would like that thanku.

[Arthur Brown]

Please remember that ALL fine powders are highly reactive, so when designing machines please ensure that there is NO way that the electrics and motors can come into contact with any powder. The old two wheeled powder mills were shaft driven from water mills, to reduce sparks.

[Patrick]

I'm going to try that as a ball mill jar. I discovered those candy containers fit perfectly into the cardboard containers ice cream stores buy their ice cream in. I can get both items for free, so I figure I'll give it a shot.

The plastic seems thick enough and the ice cream containers have nice sealing lids. Will probably have to run a little kraft around it to give it some more strength, and the cardboard tube will hold the cover on the mill jar.

That has solved my 2 week search for the best / cheapest mill jar! Can never beat free!!