Experiments with custom extruder dies – Part 2

Published on by SkyNipper

I decided to be more ambitious with my custom dies. I wanted to make some custom hollow dies for my 3-inch wall-mounted extruder from Endless Mountain Clays.

Attempt number one was a pair of all-in-one hollow dies that I printed up at Shapeways.com, in the same plastic that I used for the dies in my Scott Creek handheld extruder. The first of these immediately snapped in half like a potato chip its first time. I didn’t even bother to try the second die. Very poor design on my part, and clearly the wrong printing medium.


Fail. 

One of my printed models of a hollow die with built-in bridge.

I modeled a second attempt – a reusable bridge and a single cloud-shaped hollow die that would attach to the bridge with a M5 20mm screw. This die I had printed at a local 3D shop – Diversified Manufacturing in Middletown, CT. I wondered if the bridge would be best printed in metal to withstand the pressure, but Andrew at Diversified recommended trying a carbon-fiber material instead, since that was much cheaper. So we went that route.

This second attempt looked great, but I made a mistake – somehow, I accidentally changed the outside diameter of the bridge to 70mm instead of 65mm, and so it didn’t even fit into the extruder. Sigh. And on closer inspection of the bridge, I decided that the center support needed to be a wider diameter, enough to use a 1/4 hex bolt to hold on the die, rather than the M5 screw that I originally modeled. I felt that the screw would eventually just strip under the pressure.

So, fail.

Second attempt – looks great but wrong diameter, plus small screw.

Back to the drawing board, literally. New die, new bridge, and double-checked all measurements.

A few days later I picked up version 3 of my hollow die and bridge, stopped by Lowe’s to get the bolt and hex nut needed, and tried them out with some nice soft, recently recycled clay.

SUCCESS!

The walls of my die are quite thin, so I used a heat gun to stiffen up the extrusions before wiring them off the extruder. And my ‘cloud’ design turned out to look organic when extruded – reminiscent of a plant stem. I created a couple of simple vases, and two pairs of salt and pepper shakers from my first extrusions.

It will be interesting to see how well the die will holds up over time – I think that I will always be careful to use soft clay. Now, on to dies and bridges for 4- and 5-inch extruders!