Monday, 22 December 2008

Buiding an extruder

Following Adrian's efforts to build an extruder while I was waiting for a print I decided to have a go- not very succesfully but I think some parts have merit. I

Had some 23 mm ID aluminium tubing and an auger that was 23mm diameter. I put a goove in the top of the auger and then tapped a hole to stop the auger moving up and down.

The pipe is to supply granules to the auger .

The set up moved polymorph down the tube (And up if you reveresed it!). I then added a heated barrell and a 3mm hole and set it going and it made a small lenght of 3mm ish rod but it was very uneven and when I came to restart it from cold a plug had formed meaning I had to take it all to bits again.

Fixing Extruder issues

I have been experiencing the same problems as everyone else with the teflon barrell coming out of the bracket. This seems to happne most when the nozzle hits the work piece and it is extrremelyt annoying especially half way through a build.

I finally decided to fix it once and for all. My solution was to make a stepped piece of teflon

with a larger diameter at the top 22mm, in the middle 16mm and a jubilee clip bit at the bottom 14mm.

This is then placed into a piece of MDF with a 22mm hole at the top with a 16 mm

hole at the bottom to stop the teflon escaping. The idea of the 14mm bottom bit is to get more grip on the threaded rod so tha that part does not come out.