Milling Enclosures

I got a few questions about engraving enclosures with the desktop mill. Here is a quick explainer.

I use a BantamTools OtherMill Pro. They don’t sell this anymore and have it listed under Desktop PCB Milling machine.

What can you do with a desktop mill?

You engrave and shape 3d solid materials. I think of it as the opposite of a 3d printer. A 3d printer builds up a 3d object from nothing. The mill starts with a solid block of material and removes material until you have the final shape.

You can make 3d objects like tools, sculpted objects, custom parts, and circuit boards.

The OtherMill makes pretty good circuit boards. It’s one of the reasons I bought it. The software is able to import Eagle .brd files and generate a PCBs from these. The process is seamless and easier than you would think it should be.

It’s able to generate one-sided or two sided boards. There is a limit to trace size. The boards also do not have vias. To connect the top and bottom planes you need to solder a wire through both sides of the board.

Lately I haven’t been using the Othermill for PCBs because the cost of ordering boards through PCBWay.com is so cheap and the quality and durability of the boards is better. The cost of ordering manufactured boards is so cheap these days it’s easier to use the service.

What materials can you mill?

The OtherMill will mill a wide variety of materials.

• Wax
• Plastic
• Wood
• Aluminum
• Brass
• FR-1 PCBs

When it comes to PCBs you have to mill FR-1 which is a phenolic resin. FR-4 boards should not be milled! FR-4 is made of fiberglass and the particles generated by the mill are a health hazard.

How large a think can be milled?

The bed of the mill is pretty small. The working area is: 5.5 × 4.5 × 1.6 in. This fits 1590B, 1590BB, and 125B sized enclosures. The DD and XX enclosure don’t fit.

Where file types can you mill?

The software accepts:

• Eagle BRD (.brd)
• Gerber RS-274X (.gtl and .grb)
• G-Code (.nc and .tap)
• SVG (.svg)

I’m using Eagle .brd and SVG files. The .brd files for making PCBs and SVG files when I’m doing art for enclosures.