Detailed Guides for Every Material You Can Mill

2018-08-22 | By Bantam Tools

License: See Original Project

The magic of the Bantam Tools Desktop PCB Milling Machine is in the many materials you can mill. From plastics to metal to wood and wax, bringing digital files to life in the physical realm is even more exciting when you have a wide array of material options to choose from. We've put together detailed guides on each of the materials you can mill with our machine, complete with downloadable tool libraries, tips on fixturing, pointers on which end mills to use, and more.

Browse the materials below, listed in alphabetical order, and click on the headers to see each full guide.

ABS

ABS, or acrylonitrile butadiene styrene, is a terpolymer, meaning a combination of three polymers. ABS is a versatile, impact-resistant material that's easy to add color to and construct things with. It’s a little finicky to mill because it can melt and gum up your tool, but it’s also less expensive than some other plastics.

Community member Rodney Lobo made this milled ABS maze

Acrylic

Acrylic is a transparent thermoplastic derived from natural gas. It’s more brittle and has a lower melting point than polycarbonate but has better scratch resistance and comes in a variety of colors and textures. It can be tricky to mill because of its lower melting point, but its clarity is very desirable. It’s known commercially by such names as Acrylite, Lucite, and Perspex.

Mill acrylic to make your own Kinetic Magnet Clock

Aluminum

Aluminum is a lightweight, durable, and corrosion-resistant metal that is electrically conductive. It comes in a vast number of different alloys, each with different physical and thermal properties. The most commonly used, general-purpose alloy is 6061 aluminum, which has a great blend of strength and machinability.

Make your own custom aluminum rings with our how-to

Brass

Brass is an alloy of primarily copper and zinc. It’s desirable because it has a gold-like luster and color, a low enough melting point to be easily cast, and low friction. There are many kinds of brass alloys, each with different properties that make it suitable for different uses. For milling, we recommend 360 brass.

This tiny brass turbine was milled on the Bantam Tools Desktop PCB Milling Machine

Delrin

Delrin is the brand name for acetal homopolymer resin, which is a very hard, high-strength engineering plastic. It can withstand temperatures from –40°C to 120°C (–40°F to 248°F), and it holds its shape well over time. Despite being hard, it mills easily and gives an excellent surface finish with the right settings. It’s also self-lubricating, which allows it to be used for parts that slide against each other without wearing down or sticking.

Read how community member Eric Chu milled a yo-yo out of Delrin.

FR-1 Circuit Board (PCB) Blanks

FR-1 is a hard, flat material that consists of a thin layer of copper over a non-conductive phenolic resin. Usually about the thickness of two or three credit cards, FR-1 is primarily used for making circuit boards. The thin copper layer can be milled or etched away, leaving traces to which electronic components can be soldered. Dust generated by milling FR-1 is considerably less dangerous than dust from milling FR-4 (fiberglass).

A great beginner project is milling the Bantam Tools PCB Badge

HDPE

HDPE is an acronym for high-density polyethylene. It’s an inexpensive, lightweight, chemical-resistant, food-safe plastic that has a high strength-to-density ratio, which makes it well-suited for a vast number of applications. It can be blow-molded, injection-molded, extruded, and milled. You may recognize it as "#2 plastic" by its recycling symbol.

This is the custom HDPE fixture that Eric Chu milled for the Delrin yo-yo project mentioned above

Machinable Foam

Machinable foam is a hard, rigid foam that retains high detail, is very durable, and can be machined at high speeds, similar to machining wax. But unlike wax, it’s mostly air, so the amount of swarf generated during milling is significantly less.

Community member Eric Weinhoffer's fast engraving with air coolant, made in 5 minutes of cutting

Machining Wax

Machining wax, or machinable wax, is wax that has been mixed with plastic to make it very hard, tolerant of high temperatures, and able to retain extremely fine details. This means that it won’t melt when you mill it, and it also won’t droop, sag, or deform like many other soft materials, so you can mill very thin surfaces and tiny features, like in the head model pictured below.

Polycarbonate

Polycarbonate is a set of durable, impact-resistant thermoplastic resins that have relatively high heat resistance and color stability. It’s naturally clear and can transmit light almost as well as glass. It’s commercially known under trademarked names such as Makrolon or Lexan and has excellent milling properties.

This tiny polycarbonate component was milled for a microfluidics project

Wood

There are many kinds of wood, with many different uses. Our machine can mill all of them. Softer woods like plywood or balsa are useful for jigs or quick models but may not give a great surface finish due to their long grains and low density. Hardwoods like mahogany, purpleheart, or cherry mill more slowly and can be given a beautiful surface finish.

This tiny coffee pot was milled out of walnut wood

With so many options, we can't wait to see what you make! As always, don't hesitate to reach out via support@bantamtools.com if you have any questions. Also, be sure to share your creations with us by sending in a picture or adding #bantamtools to your social posts.