Open Source Ball Mill

Basics

• Part of the Open Source Laboratory Construction Set
• It is essentially a cylendar placed on its side, it has an axis going down the center of it's axis as well (preendicular to the circle faces), this is spun causing the material placed inside to repeatidly fall carying ball bearings with them, these then meet and collide on the cylendar walls. This process is repeated untill the internal materials are powderized to the desired consistency. Then the contents are removed and seperated. (PS Sorry if this rambled a bit, feel free to simplify it)

Generally Used For

• Making powder for Selective Laser Sintering 3D Printers
• Powderization of solids
• Mixing of said powders

3D Printing Uses

Ball mills can be used to grind down a medium to a powder, which could be useful for the application of selective laser sintering, where a powder (ie: plastic, aluminum, stainless steel, titanium, etc) is sintered into a 3d model by a laser.

Comments

Comments by Michael Altfield

I (Michael Altfield) used to make ball mills for grinding shredded aluminum foil into a fine powder for thermite.

My first ball mill I bought for $20 from unitednuclear.com. It was the simple 3lb rotary rock tumbler. Iirc, the rubber belt-drive broke on it, so I ended up making my own. I would scrap motors from wasted electronics like standing osculating fans, hook the drive up to a long threaded rod, and use that to spin the cylindar.

The aluminum powder I made was very, very fine. The aluminum was sourced from aluminum foil passed through a nice-ish paper shredder then grinded in the ball mill.

Could we 3D print aluminum parts from aluminum powder produced from a ball mill?

Also, it's worth noting that there is a strong correlation between aluminum exposure and Alzheimer's Disease. If we ever did work with Aluminum Powder, we should probably wear protection like the workers do at Materialize.com

Eric's Comments on Your Comments (Comment-ception)

• First of, cool respirator + face sheild! I was looking at the version that added a flip down welding mask. Expensive, but useful. How often do you need to relace the blower cartriges?
• Anyhow on the note of using aluminum powder, it might work, but I am unsure if the oxidzaion of the powder could effect anything. Otherwise though it might be fine.
• Another option is to start with plastic sls/slm and work our way up from there? This design that was at MRRF could work, albeit in a less gittery and more D3D form.

Existing Open Source Designs

• [This one might honestly be ready to use with the addition of a housing, motor, and motor control system (also maybe scale up/down)]

Minimum Viable Products

• Scaleable
• Modular
• Quick Removal of Main Container for Little Delay Time In Use
• Noise Reduction
• AC or DC input power

Basic Design

Container

• A cylendrical container in which the grinding takes place
• Needs to Be Durable
• Also has the addition of the axis through the middle

Mechanism

• The part that takes the rotation from the modor and adapts it to the axle of container
• Could be as simple as direct attatchment or much more complex

Housing

• The shell in which all the above componets are contained

Balls

• Stainless Steel Ball Bearings work well for most cases
• Ceramic or Teflon are better for more reactive substances

Other DIY Ball Mills

• Gizmology version - [1]

Internal Links

• 3D Printer

External Links

• [Wikipedia Page on Ball Mills]
• Wikipedia:Sintering