Metal CNC Milling Guidelines

A lot of you, fellow ZMorph machines users asked whether or not metal milling is possible. Metal parts are more rigid and expand the usability of your all-in-one machine. After a thorough testing process and a lot of consideration we have come to one conclusion: Yes, we can.

This is a third guide on CNC milling with ZMorph VX by our expert Roman Broda. Read also how to avoid breaking cutters and workpiece holding solutions.

But before you run to your machine and dig into those shiny materials, take a few minutes to read this article.

Metal CNC Milling Guidelines — CNC milling in metal with ZMorph VX.

We will cover the most important aspects of metals milling to keep you, your environment and your machine safe.

Safety

May the safety be with you.

Yours and your environment safety have to always come first. There are three aspects of safety to consider: the safety of the user, the safety of the environment and the safety of the machine itself (the order is not a coincidence).

Always wear protective glasses when working with the CNC PRO toolhead. No matter whether it's tool changing, setting zero coordinates or cleaning the machine. Protecting your eyes is important.

When the machine is working it should have closed covers. If your cutter breaks, it can be thrown in various directions and harm anyone near.

Last but not least: chip clearing. The machine is well protected against milling chips, but every now and then vacuum off metal shavings.

Materials tested on VX

Make the workmanship surpass the materials.

As mentioned before - milling metals is a much harder process than milling in plastics and wood. To make sure all of you have the same starting point in this table you will find basic parameters for milling.

Material	Operation	Cutting speed [mm/s]	Lead in/out speed [mm/s]	Maximum stepdown [mm]
Aluminium PA6PA9	Cutting / Engraving	1.50	1.25	0.15
Brass M63	Cutting / Engraving	1.50	1.00	0.10
Brass MZN12 (Silver Nickel)	Cutting / Engraving	1.00	0.8	0.05
BronzeB2B43	Engraving	1.00	0.8	0.10
Copper M1 ER	Cutting / Engraving	1.75	1.25	0.15

As you can see, the milling speeds are not the highest but using a combination of these parameters and materials is safe and shouldn’t generate any unexpected problems (provided using safe operation parameters). If you would like to use different materials (or different alloy) remember to be extra cautious when setting up the job.

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Workholding

With high milling forces comes great responsibility.

Responsibility of your workholding of course. When mounting your stock material use only the most reliable workholding solution you can find. Improperly mounted material will surely fly off the worktable damaging your machine and even you.

When choosing your fixture, take into consideration these tips:

Metal milling generates high temperature. Therefore when using 3D printed fixtures, use only those printed from heat resistant materials like ABS or PET-G. Vise with PLA jaws can deform from temperature (see the photo below)

Double check if your stock material is properly mounted. One way to do this is to grab your mounted material, lift it with CNC table and “shake well”. If it holds, you should be safe
Make sure that your cutter doesn’t hit your fixtures. You will destroy your fixture (for sure) and most probably also your product

Milling cutters

One does not simply use a dull cutter in metal.

Your cutter is the thing that makes the hardest work during milling. It needs to be sharp and of proper geometry to easily shear through your stock.

To make sure your part turns out perfect, follow these tips:

When browsing through shops, look for cutters described as designed for metals (aluminum, brass, etc.). The difference is in the geometry of cutting edges of milling cutter but these are details you shouldn’t bother with.
Always check your cutter tip when starting your operations. Look for any damaged edges and also if the tip is not blunt. A sharp tip is shinier than a dull one so it should be easy to distinguish them.

And that should be all. Carefully implement those tips into your projects and in no time you will get great quality metal parts.

CNC Milling in Metal Samples — Samples of CNC milling in metals with ZMorph VX

Expand Your Manufacturing Knowledge

ZMorph Materials Library is a comprehensive guide to all materials compatible with ZMorph VX Multitool 3D Printer. This resource will give you an extensive outlook on a wide range of additive and subtractive fabrication materials supported by the machine.

Discover endless manufacturing possibilities with materials divided into three categories: 3D printing, CNC milling, and laser cutting and engraving.