select
navigate
switch tabs
Esc close

Any experiences with plastic CNC machining (POM)?

0
M
4

Hello!

I’m planning to use CNC machining for plastic parts (Delrin/POM) for the first time and have typically worked with metals before. I’m considering the ‘as machined’ finish with a standard 3.2 µm surface roughness.

For those who have experience with plastic CNC machining, can ‘as machined’ parts generally be used as end parts, or do they often carry too many machining marks? Would it be better to choose a bead-blasted finish (or another type) to enhance the appearance? These early prototypes might be shown to our end customers, so they need to look reasonably good. Any tips or experiences would be very helpful.

Also, could anyone share some pictures of polymer parts you have produced using CNC machining? I’d appreciate it!

Thanks, Marcin

Solved by Pierre-Yves Huet
Hello Marcin, Regarding the aspect, I would not recommend Bead blasting on this plastic material, because it will give a dull/grayer finish, which will be very noticeable if the material is black. The "as machined" aspect is generally appreciated for this material, and it can be specified on drawing to avoid machining marks, which leads to using a finishing milling step to keep the milling traces as small and discrete as possible. In my experience as support engineer, I can affirm that a lot of customers order parts in this material as an end part, without additional treatment or finish, but if the aspect is very important, you can specify a lower roughness, like Ra 1.6um, and indicate which surfaces should be ideally without tool marks. Best regards, Pierre-Yves
    • M

      Hello!

      I’m planning to use CNC machining for plastic parts (Delrin/POM) for the first time and have typically worked with metals before. I’m considering the ‘as machined’ finish with a standard 3.2 µm surface roughness.

      For those who have experience with plastic CNC machining, can ‘as machined’ parts generally be used as end parts, or do they often carry too many machining marks? Would it be better to choose a bead-blasted finish (or another type) to enhance the appearance? These early prototypes might be shown to our end customers, so they need to look reasonably good. Any tips or experiences would be very helpful.

      Also, could anyone share some pictures of polymer parts you have produced using CNC machining? I’d appreciate it!

      Thanks, Marcin

      0
    • P
      Xometry Engineer

      Hello Marcin,
      Regarding the aspect, I would not recommend Bead blasting on this plastic material, because it will give a dull/grayer finish, which will be very noticeable if the material is black.

      The “as machined” aspect is generally appreciated for this material, and it can be specified on drawing to avoid machining marks, which leads to using a finishing milling step to keep the milling traces as small and discrete as possible.

      In my experience as support engineer, I can affirm that a lot of customers order parts in this material as an end part, without additional treatment or finish, but if the aspect is very important, you can specify a lower roughness, like Ra 1.6um, and indicate which surfaces should be ideally without tool marks.
      Best regards,
      Pierre-Yves

      0
      Reply
      • M
        Pierre-Yves Huet

        Thank you!

        0
        Reply
    • A

      What Mr Huet replied is accurate – I have similar experience. Here’s also a picture I just made of one of my recent ABS CNC machined parts, you can see that there are traces of milling, but they are not too visible. 

      0
      Reply
      • M
        AM_EngR

        Thank you for sharing, that looks good, indeed. Nice texture 🙂 

        0
        Reply
Any experiences with plastic CNC machining (POM)?
Your information:




Suggested Topics

Topic
Replies
Views
Activity
Printed aluminum parts in pressure applications
Hi! Questioning about prototyping a hydraulic valve housing (normally CNC’d in 6061) - considering aluminum 3D printing instead, mainly to speed up design iterations. The part would see ~150 bar during bench tests, with... read more
T
0
67
Sep 29
High-temperature chemical pump housing in PEEK, tips on avoiding warpage?
Hi everyone, I'm working on a small pump housing for a chemical metering application. The part will be injection molded in PEEK, exposed to roughly 180 °C fluid and aggressive solvents. It's a compact... read more
S
R
4
178
Sep 30
Issues with polyurethane bonded rollers under load
Hi! Currently working on a small batch of U-groove guide rollers for a linear transfer system, and I'm using a soft polyurethane tread (around 85A Shore) bonded to aluminum hubs. The supplier estimates each... read more
P
A
4
671
Aug 19
Best fixture setup for milling and drilling mid-size batches of aluminum brackets?
Hi, I've got a batch of aluminum brackets that need to be drilled and milled on all sides with high repeatability. Has anyone designed a modular fixture system for parts like this to reduce... read more
h
u
a
9
947
Aug 22
Vacuum casting for snap-fits
I’m planning to use vacuum casting to produce about 50 housing units with integrated snap-fit features for an electronics prototype. The parts need to survive multiple assembly/disassembly cycles during testing. I’ve seen mixed opinions... read more
J
A
j
9
1.0k
Aug 11