Delrin

Store-Material-Delrin-Black0.25in

What is 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 a really nice finish with the right settings. It’s also self-lubricating (aka slippery), which allows it to be used for parts that slide against other parts without wearing down or sticking.

What is Delrin used for?

From the manufacturer: Delrin is used for high-load mechanical applications, such as gears, safety restraints, door systems, conveyor belts, healthcare delivery devices, and components across a diverse range of products and industries.

A number of the Othermill’s parts are made of Delrin, notably the bearings and anti-backlash nuts used in all the carriages. When milling Delrin, Othermill users mostly make mechanical parts.

Is Delrin safe?

Yes! But as with all materials, we don’t recommend inhaling or eating the swarf.

Where can I get Delrin?

We sell pre-cut pieces of both black and white Delrin in our store. They’re the perfect size for many Othermill projects, and they fit nicely on the Othermill bed.

Fixturing: How do I attach Delrin to the bed of my Othermill?

Nitto Permacel P-02 tape or hot glue are both good options.

To use Permacel tape, place strips evenly across the underside of the material. Then peel off the backing, and press the material firmly down onto the machining bed.

Delrin1

Delrin2

To fixture your material with hot glue, run a bead of glue around the bottom edge of the material, where it meets the bed. If you use the alignment bracket, you only have to glue the sides that aren’t touching the bracket.

Note: Don’t put glue on the bottom of the material and then stick it down because this will make the material taller, which will cause your endmills to cut too deeply.

Delrin3

If you’re feeling ambitious, you can remove the spoilboard, attach the material with tape, drill holes in the material that align with the slots in the T-slot bed (see Dimensions and Diagrams), and then bolt the material to the bed with low-profile M5 bolts. This provides extremely strong fixturing.

What endmills should I use when milling Delrin?

In general, larger tools like 1/8" and 1/16" endmills are better because they cut through material the fastest and are least likely to break. For 3D shapes like the yo-yo project below, a 1/8" or 1/16" ball endmill produces the smoothest contours.

For best results, keep a set of endmills specifically for Delrin and other plastics, and never use them to cut metal or PCBs. This allows for increased milling speeds and a better finish.

What are some example projects?

The OtherYo

Delrin4

Breakfast Heroes

Delrin5

Othermill Sharpie Tip Adapter

Delrin6

Note: The feeds and speeds below are optimized for the V2 Othermill. If you are using an Othermill Pro or Kickstarter Othermill, you may need to experiment to find optimal settings.

Recommended Feeds and Speeds

Download The Custom Tool Library for Delrin
To make it easier to use these recommended feeds and speeds, we’ve created a way for you to quickly import into our software all the settings you see listed below. To do this, first, download this file, which contains all the recommended feeds and speeds for this material. Then open our software, click File > Tool Library, click the “Import” button, and select this file. Before using these settings, it’s a good idea to read through our Feeds and Speeds Guide.

Download the Custom Tool Library here.

Tool: 1/8" flat endmill
Feed rate: 23.622 in/min (600 mm/min)
Plunge rate: 1.575 in/min (40 mm/min)
Spindle speed: 12,000 RPM
Max pass depth: 0.008" (0.21 mm)

Tool: 1/16" flat endmill
Feed rate: 23.622 in/min (600 mm/min)
Plunge rate: 1.575 in/min (40 mm/min)
Spindle speed: 12,000 RPM
Max pass depth: 0.020" (0.5 mm)

Tool: 1/32" flat endmill
Feed rate: 23.622 in/min (600 mm/min)
Plunge rate: 1.575 in/min (40 mm/min)
Spindle speed: 12,000 RPM
Max pass depth: 0.020" (0.5 mm)

Tool: 1/64" flat endmill
Feed rate: 23.622 in/min (600 mm/min)
Plunge rate: 1.575 in/min (40 mm/min)
Spindle speed: 12,000 RPM
Max pass depth: 0.003" (0.08 mm)

Tool: 1/100" flat endmill
Feed rate: 23.622 in/min (600 mm/min)
Plunge rate: 1.575 in/min (40 mm/min)
Spindle speed: 12,000 RPM
Max pass depth: 0.003" (0.08 mm)

Tool: Engraving bit
Feed rate: 23.622 in/min (600 mm/min)
Plunge rate: 1.575 in/min (40 mm/min)
Spindle speed: 12,000 RPM
Max Pass Depth: 0.003"–0.020" (0.08 mm–0.5 mm) Keep in mind the engraving tool is V-shaped and thus has a variable width, depending on your “engraving cut depth.” The deeper the cut, the wider the tool. The shallower the cut, the narrower the tool. If you’re using an engraving tool and the generated path isn’t cutting part of your .svg file, try reducing the engraving cut depth.

Advanced Feeds and Speeds

Warning: These settings are for advanced users. Before using any of the information provided here, you must read the section above on fixturing your material. The feeds and speeds specified here are more aggressive (and thus faster and more fun), and improperly fixtured material can be knocked loose and damage itself and your machine.

Tool: 1/8" flat endmill
Feed rate: 59 in/min (1500 mm/min)
Plunge rate: 5 in/min (127 mm/min)
Spindle speed: 16,400 RPM
Max pass depth: 0.02" (0.5 mm)

Tool: 1/16" flat endmill
Feed rate: 59 in/min (1500 mm/min)
Plunge rate: 5 in/min (127 mm/min)
Spindle speed: 16,400 RPM
Max pass depth: 0.02" (0.5 mm)

Tool: 1/32" flat endmill
Feed rate: 59 in/min (1500 mm/min)
Plunge rate: 5 in/min (127 mm/min)
Spindle speed: 16,400 RPM
Max pass depth: 0.02" (0.5 mm)

Tool: 1/64" flat endmill
Feed rate: 59 in/min (1500 mm/min)
Plunge rate: 5 in/min (127 mm/min)
Spindle speed: 16,400 RPM
Max pass depth: 0.01" (0.25 mm)

Tool: 1/100" flat endmill
Feed rate: 59 in/min (1500 mm/min)
Plunge rate: 5 in/min (127 mm/min)
Spindle speed: 16,400 RPM
Max pass depth: 0.005" (0.13 mm)

Tool: Engraving bit
Feed rate: 59 in/min (1500 mm/min)
Plunge rate: 5 in/min (127 mm/min)
Spindle speed: 16,400 RPM
Max Pass Depth: 0.003"-0.020" (0.08 mm–0.5 mm) Keep in mind that the engraving tool is V-shaped and thus has a variable width, depending on your “engraving cut depth.” The deeper the cut, the wider the tool. The shallower the cut, the narrower the tool. If you’re using an engraving tool and the generated path isn’t cutting part of your .svg file, try reducing the engraving cut depth.