Make Thermal Barrier With Drill Press

Start with a 3/8 inch peek rod. The actual diameter isn't too important, but I found thinner is cheaper and this was about as thin as I felt would be strong enough. I ordered mine from [1]. You can also use PTFE.

Cut a 32 mm length. I clamped it in a vice and used a block of wood as a guide and cut it with a hack saw.

Next, use a 10mm x 1.5 die to put a thread on the outside of one end. Aim for about 7 full threads, which required that I make 10 full turns with my die.

In order to drill straight down the rod we need to build a jig to hold it in place. Start by clamping a block of wood to the drill press' bed. You will need to have room between the drill press chuck and the top of the block of wood to use the hand tapping tool. Do one final check to make sure everything is locked down tight. Once you drill the next hole, the block of wood must remain stationary.

Drill a hole with an 11/32 inch drill bit that is 30 mm deep. Use the hand tap with a 10 mm tapping bit to tap the hole you just drilled. I marked the bit before I started so that I knew when to stop. If you go too far, you could damage the thread.

Screw the tapped end of the PEEK into the hole as far as you can without damaging it. Don't worry if you can't get it in completely, it will be turned by the drill and tighten up.

Drill a 3.5 mm hole all the way through the PEEK. Drill a #20 hole 15 mm deep into the PEEK. Tap the hole with a 6 mm tap. Do not go past the 15 mm deep hole you drilled earlier as this will create a void where plastic will form a bulge and damage the thermal barrier over time. It is a good idea to mark the tap with a piece of tape so you know where to end. Finish the thread with a 6 mm bottoming tap.

You will probably need a pair of vice grips to remove the PEEK. Make sure the finished piece fits on the heater barrel and that the filament moves easily between them.