Small scale wheel mill idea

[Pirotecnia]

I'm thinking about building a very small scale wheel mill, inspired in the real ones used in the black powder industry, but for batches of about 100 grams of powder.

Each wheel of a real size wheel mill weights about 5.5tons and obviously in a small scale, the wheels (I'm thinking of using bronze) will weight just some 3 or 4 kilos.

My question is, due to the small size/small weight (but also equivalent small batch of composition to be milled), will it be as efficient as a real one?

[PyroGb]

Yes I think so just so long as you scale everything down the same amount exe (all parts= 1/50 scale) or however small you want. however I think you could make it even more efficient by useing something like machined aluminum  (again I’d have to do reasearch on the quality and efficiency of the real one) I think just so long as it is big enough for the balls to roll freely you should be good. I think it’s a great project good luck show us when your done 😄

[Arthur]

My biggest fear would be spillage, spreading highly flammable powder all over the place. Remember that wheel milling for BP was done wet.

[cmjlab]

What would be the advantage of a small scale wheel mill besides historical accuracy?  I feel like it would cost significantly more to make, and would mill less in the same amount of time you could with a cheaper to build "efficient ball mill".  Just curious is all.

[cmjlab]

Cool idea, id sure like to see a scaled down version I could use to make milled Mg/Al so that it has constant exposure to oxygen and could eliminate some of the risk of ball milling Mg/Al.

[Pirotecnia]

The main reason is for safety, I think wheel mills are a bit more safer than ball mills in case of ignition inside the container mainly because the composition is not confined.

Edited January 6 by Pirotecnia
text fix

[cmjlab]

Makes sense.  I guess it is probably safer from a impact / friction standpoint as well.  The grinding wheells don't actually touch the surface in the trough where you add the chems right?  It floats above by a tiny distance was the way I understood it.... But I've never actually seen one in person.

Edited January 6 by cmjlab

[Pirotecnia]

Yes, thats true, the latest mills of this kind are made in a way that the wheels don't touch the pan and also the wheels are suspended by rods with shafts independent from each other, so in the case of some strange particle in the mix (a nail for example), they can lift individually preventing excess of friction. This kind of mill and also ball mills (drums) and the whole industrial process of making black powder and even the refining of its ingredients is well described in the book "The Manufacture of Explosives - Vol I" by Oscar Guttmann (about the mills from page 194 to 201).

[Zumber]

In all aspects of safety concern wet miiling is excellant though it would take a time to dry powder and sieve again.

I personally prefer it a lot.

[Arthur]

I have once seen a picture of a "Spice Mill" that was for sale. It was NOT a blade mill but a flat stone disc with two stone rollers exactly like a Royal Gunpowder Mills wheel mill in desk top scale. Sadly this was the ONLY mill I've seen like this, and this was a couple of years ago. 

HOWEVER what I do like about mill jars is their ability to contain the dirty dust that is part milled powder. 

[Pirotecnia]

Just found a new video about Parente Fireworks factory in Italy - it seems they use a ball mill to mill charcoal and a relatively small wheel mill to incorporate the 3 ingredients: 

 

[cmjlab]

Thanks for sharing the video, I've never seen that one.  Makes me want a wheel mill too!  I just don't have the $3k+ required to buy a used small version, nor could I truly justify it.  Still - a man can dream!