635 replies to this topic

[newtoolsmith]

Hi friends,

I try...

@BrightStar:

when talking about 95rpm at the milling jar and ratios of 0,28 and 0,27 the motor speed is 1257rpm.

That seems to be very slow. The motor should be able to run much faster.


@adamw:

No attachments optin available.

MfG
newtoolsmith

Edited by newtoolsmith, 02 September 2006 - 08:22 PM.

[newtoolsmith]

I found a server to host my pics. they will be visible for you all soon!

MfG
newtoolsmith

[newtoolsmith]

Hi friends,

here are the pictures I promised.

The first shows the mills casing made from waterproof plywood.

http://picture.digim...41_phpxD6H9.jpg

On the second picture you can see the sifted out electronic. This includes the power supply and the speed regulation.

http://picture.digim...06_phpITgZ7.jpg

The milling jar is placed on the platform in picture three. The two parallel shafts are driven synchronous by a bike chain and gearwheels. This gives excelent traction. The DC motor with mounted gearbox needs 24V/5A.

http://picture.digim...30_phplfePd.jpg

The casings top contains a ventilator and a noise reduced airchannel. The needed 12V are made by soldering in a resistor in series. The resistor itself needs intense cooling! It terminates approx 6W!

http://picture.digim...17_phpyTQU9.jpg

Last but not least the way from alu foil to powder is shown. Reached mesh size unknown but screens are beeing built... Its realy fine and feels smooth so 300 ore more mesh might be real.

http://picture.digim...59_phpiPHJt.jpg


I hope the links work and you enjoy them.

MfG
newtoolsmith

Edited by newtoolsmith, 13 September 2006 - 09:52 PM.

[Stew]

Hey all just wondering if the lead balls at the bottom of this page would be non-sparking and ok for milling some BP? http://www.sutlers.c...ssories_39.html Cheers.

[newtoolsmith]

Hi friends,

I told my Al-foil-milling-story before and here is another result:

I sieved the resulting powder a,d found that approx

25% are bigger than 50 mesh

25% are bigger than 150 mesh and

25% are bigger than 325 mesh.

The fourth 25% are -325 mesh.

I dont have a sieve finer than 325 mesh but I hope the -325 mesh fraction will be good enough for flash. The particles will be very flat flake shape so the chance is quite good.

MfG
newtoolsmith

[EnigmaticBiker]

Hey all just wondering if the lead balls at the bottom of this page would be non-sparking and ok for milling some BP? http://www.sutlers.c...ssories_39.html Cheers.

Yes, there should be no problem, as far as I know they are lead/antimony mix.
They seem a bit small but should be adequate.

I use copper pipe (22mm) filled with lead/antimony alloy.

There are loads of threads here on this subject.

[Stew]

K cheers. Yeh i looked on the milling media thread but cudnt find nething specific so i just posted on here because this is where found the link in the first place thnks again.

[BrightStar]

At last, my ball mill is back in action! I promised details, so here they are:





A video of the thing in action with a jar full of media is here:

Ball mill video - (3.6 MB divx avi)

The motor is a 0.25hp cap-start 4-pole induction motor (approx 1400 RPM speed) found as surplus on ebay for ?20 - definitely bargain of the year. First measurements suggest that it consumes about 140w. The thing is fan cooled, non sparking and sealed to IP55.

The rest of the contraption, as before, uses 8mm studding, roller blade bearings secured with pipe clips, cheap Tufnol pulleys and 30mm PVC tube rollers painted with primer for grip. The 'drive belts' are a few turns of cotton twine. The woodwork is painted with white gloss to resist evenings in the garden...

It's running a bit fast for the jar at the moment at 110 RPM, so I'll slow it down to the optimal 95 RPM before use.

newtoolsmith: Enjoyed seeing your new mill - how are you controlling the DC supply to the motor for variable speed? Is the sound insulation effective? Mine is LOUD!

Edited by BrightStar, 27 September 2006 - 06:48 AM.

[Asteroid]

Why is black powder milled in a ball mill as a complete compostition? Surely if it was milled as seperate ingredients it would eliminate the need for non-sparking media?

Also, how do you use a microscope to deterrmine the size of particles (below 1mm)?

[fishy1]

Why is black powder milled in a ball mill as a complete compostition? Surely if it was milled as seperate ingredients it would eliminate the need for non-sparking media?

Also, how do you use a microscope to deterrmine the size of particles (below 1mm)?

Blackpowder's milled in a ball mill as it mixes them together better and beats all the components together. It's one of the few comps it's safe to mill as it's RELATIVELY insensitive.

[BrightStar]

Can I just say, there is nothing more satisfying that the rumble of a happy ball mill after a hard day at work.

Mine's making up a small batch of Tiger Tail out in the garden. Shouldn't take long...

Yours, a contented pyro

:Asteroid - search and you will find...

[fishy1]

Can I just say, there is nothing more satisfying that the rumble of a happy ball mill after a hard day at work.

Mine's making up a small batch of Tiger Tail out in the garden. Shouldn't take long...

Yours, a contented pyro

:Asteroid - search and you will find...

I remember before I had a ball mill and I made up 200g of TT with a pestle and mortar. Never again, took hours, I like my ball mill. Mark 2 will be built soonish, with at a guess 15kg of lead media.

[karlfoxman]

15kg! How much composition are you planning on milling?

[Andrew]

15kg of lead media equates in volume to about 5kg of ceramic media.
This in turn equates to a 5L (give or take) mill jar. In terms of bp a jar like this could mill a batch of around 700g.

All roughish estimates!

[fishy1]

15kg! How much composition are you planning on milling?

at a rough estimate, 1kg at a decent speed.