The Extruder Works!

10 05 2010

I built the extruder that I posted about last and I have been testing it for a while now. I’m just using ABS for now because I’ll have to change a few things for it to work with PLA.

I changed a few things from the design I posted. First off, I didn’t have any PEEK (and it’s really expensive so I didn’t want to buy any) so I just used some PTFE. I’ve got a block of PTFE that is a half-inch thick. I just drilled the requisite holes using the original washer as a template. This worked really well to get the spacing right.

Also, I just used some nichrome wire and wrapped it around the barrel in one layer instead of using a HeatCore. It was much easier than making a new HeatCore.

And also, instead of some fancy insulator, I just used a piece of PTFE. That was all I had around, so that’s what I used. I just drilled a 3ish mm hole in it and carve a little out at the bottom so it would sit well on the top of the barrel.

And finally, because I’ve been having problems with plastic leaking around the nozzle threads, I just soldered the nozzle onto the barrel. The one thing I hope is that the solder isn’t melting. If it is, it could short the nichrome, clog the nozzle, and a bunch of other bad stuff.

This extruder has been working well for ABS so I might try it with some PLA soon. I was thinking I could remove the PTFE insulator at the top and see if that makes it work nicely. The ABS has been leaking around the PTFE at the top a little, and that could cause a pretty substantial jam with the PLA. I was thinking I could add a small metal pipe just above the barrel to guide the filament into the barrel. It would be cooled with a heat sink to make sure it stays below PLA’s glass transition temp.

Anyway, that’s the newest update on my extruder escapades.




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