635 replies to this topic

[miniskinny]

Well, I made a Ball Mill with a drill, with adjustable speed . I attached a 3/8 metal rod onto the drill bit entry, and put a rubber tube over the aluminum rod for a bit a traction. I then put the other end of the rod into the center of a lawn-mower wheel. I then just had a wooden dowell to the left of the rotating rod; same thing, just no motor moving it. Works perfectly! I can adjust the speed to be around 50 rpms, all the way up to an rpm that is unusable. I can also adjust my ball mill to make it a slow metal grinder!
EDIT:
Got my camera, about 10 minutes after I posted
Don't have a picture of the metal grinder addition yet though...

Overhead View
Close-Up of Speed regulation

Edited by miniskinny, 11 September 2004 - 11:01 PM.

[alany]

I suspect that won't last long... Electric drills are not rated for continous operation.

It is also a universal motor, meaning it has brushes, which is a potentional ignition source.

[Patrick]

I suspect that won't last long...  Electric drills are not rated for continous operation.

It is also a universal motor, meaning it has brushes, which is a potentional ignition source.

Yes, A drill will overheat. I'd look into a appliance recyling center. I picked up two 1/2 HP 1145/1725 motors off of washing machines and a 1/4 HP 1725 motor off of a dryer. I also got the plugs, belts, and pulleys. Took a bit to find some, as most were rusted or already removed. The nice thing is they are all free!

I made the ball mill out of passfire.com, as I had plenty of 2x4's lying around. I purchased regural bearings and just mounted them between two pieces of 1x2 with a 1 3/8" indent drilled to hold the bearings.

I'd submit a pic, but as I said it is basically the same as passfire.com. I was thinking of making a smaller one for smaller quanitys of chemicals.

[mleech]

Hm, United Nuclear's 3 pound ball mills look a lot like the one chim-chim just mentioned...But as for me, I found that a cheap little rock tumbler, and some fishing weights (I believe they mostly stopped making them out of lead, since fish eat  them and get fairly sick  ) milled up my Potassium Chlorate 80 % and red wood charcoal 20 %, came up with some plenty fine gun powder. I suppose I may be needing a larger-sized rock tumbler later, or perhaps I'll make one. That formula up above works fine despite it not having any sulfur in it, since it's not a good idea to have sulfur and chlorate getting mashed together.
mini

With the possible exception of carbonate colouring compounds, it's not a good idea to
mill Chlorates with *ANYTHING*. While H3 (Chlorate and Charcoal) is relatively
tame in use, the proper method for making it is to screen the two ingredients together,
having milled them separately.

Milling Chlorate/Fuel mixtures is asking for a large and possibly-lethal explosion at some point.

In fact, milling any oxidizer/fuel combination OTHER THAN BLACKPOWDER in a ball mill
is extremely hazardous. Don't do it!

[miniskinny]

Actually, a lot of comets involving KNO3 and Charcoal require ball-milling...But I do now agree with you mostly about what you just said...Except in most cases you can ball mill a compound that only has KNO3 as an oxidizer...One of the exceptions is KNO3 flash powder...obviously.

[Creepin_pyro]

Just thought this might possibly be of some use.......

Everyone who has made a ball mill will know about gearing, getting the rollers spinning at the right RPM, but once you've got it set, there's no way to change the speed without changing the gears, right?

At first, I couldn't work out how the RPM dial on my ball mill changed the speed, but upon further inspection..... The motor sits on a sliding metal platform, rather like a vice. Turning the knob slides the motor forwards and backwards, varying the tention on the drive belt. This speeds up and slows down the rollers, just by pulling the motor further away.

I'm still confused about quite how this works, but I thought the principal wouldn't be too hard to implement on a home-made mill.

[BigG]

Just thought this might possibly be of some use.......

Everyone who has made a ball mill will know about gearing, getting the rollers spinning at the right RPM, but once you've got it set, there's no way to change the speed without changing the gears, right?

Well, not really. The motors on both my BM and Star Roller are variable speed. I change the speed by verying the voltage going in. At 240 they go max RPM, at 120 they go 0 RPM, anything in between changes the speed - so 180 will run the thing at 50%.... (Actully - on my star roller the motor is 0-24 volt, resulting at 0-500 rpm)

[Jerronimo]

Turning the knob slides the motor forwards and backwards, varying the tention on the drive belt.  This speeds up and slows down the rollers, just by pulling the motor further away.

I would think that when you've got more tension on the drivebelt you will get a higher rpm.
When the tension is lower however some slipping of the drivebelt on the pulley will slow down the RPM.

[Patrick]

Just thought this might possibly be of some use.......

Everyone who has made a ball mill will know about gearing, getting the rollers spinning at the right RPM, but once you've got it set, there's no way to change the speed without changing the gears, right?

At first, I couldn't work out how the RPM dial on my ball mill changed the speed, but upon further inspection.....?? The motor sits on a sliding metal platform, rather like a vice.? Turning the knob slides the motor forwards and backwards, varying the tention on the drive belt.? This speeds up and slows down the rollers, just by pulling the motor further away.

I'm still confused about quite how this works, but I thought the principal wouldn't be too hard to implement on a home-made mill.

Sounds like belt slippage. Also if you have too much tension it will slow the mill down due to higher friction (a break). You really don't want either of those, as the motor work will then be turned into heat .. either added work to the motor from bogging down, which could overheat the motor. The other would be with the slippage and the pulley heating up the belt and eventually wearing it down.

I have dual speed motors for my ballmill and corning machine. They are 1/2hp 1145/1725 rpm motors off of washing machines. I run them on the 1145, but could easily switch them to 1725, with making a change in the wiring. I actually have about 6 extra lying around, need a few spares I guess!

I would think that when you've got more tension on the drivebelt you will get a higher rpm.
When the tension is lower however some slipping of the drivebelt on the pulley will slow down the RPM.

The more tension = more work for motor = slower operation

Too much or not enough tension is bad. You need a happy medium that has little to no slippage, but not a lot of added tension.

Edited by Patrick, 09 October 2004 - 01:14 AM.

[Creepin_pyro]

I thought the design was a little strange myself, but it is a commercial mill, so there must be some merit to it

[Arthur Brown]

suggest a spring loaded V-belt pulley, more latteral force pulley opens further and belt goes closer to the centre, changing the effective diameter.

[broadsword]

continued from http://www.ukrocketr...opic=1176&st=30
I only have a small container and it seems to do the jb of crushing and mixing all my chemicals together! But it jus seem that the Bp that comes out has no real difference to the stuff i was using before? Any Ideas?

[Pretty green flames]

For how how long do you mill your BP

Any difference in burn rate when testing it

[RegimentalPyro]

continued from http://www.ukrocketr...opic=1176&st=30
I only have a small container and it seems to do the jb of crushing and mixing all my chemicals together! But it jus seem that the Bp that comes out has no real difference to the stuff i was using before? Any Ideas?

First of all - well done for breaking off a side discussion into a more appropriate area.

What sort of charcoal are you using? It's quite important when making good BP. Softwoods [Willow, plum, grapevine] make the best charcoal for good fast lift BP.

Also how long, and what are you milling? I mill the KNO3 for 2 hours, and the Carbon & Sulphur [+Dextrin if making pulvorone] for two hours. Then I mix them together and mill the mix for three hours.

NB: I do this more as a risk reduction strategy than as a mechanism for making good BP, but it does seem to work.

Your milling jar should also be half full of media and a quarter full of whatever you are milling for good results.

[broadsword]

well i have finishd some 6hr milled BP today and it seems to be ok. But i will be making my own charcoal soon out of some dry cherry tree i have in my garden! But i figured that using lumpwood BBQ charcoal would be OK whilst i am still perfecting the art of making BP.

What sort of time should i be looking at to make a good allround BP suitable for many things, or is this not possible?

If i was to make lift powder out of it would i need to make it in to pulverone?

Edited by broadsword, 13 December 2004 - 12:25 AM.