Sunday, June 27, 2010

Some Progress on the extruder

After more than 50 iterations on my "JunkStruder" as I like to call it, a major delay in acquiring fibreglass coated Nichrome to overcome the intense heat needed to extrude PLA, ~275 degrees Celsius seems to be working, but not by the stepper yet.

I did have a big problem that I was very happy in my decision to use a BakeLite thermal break was a good one.
Essentially I broken the filament right at the top of the thermal break, gah!  But when I applied a butane torch flame, yeah that's right a butane torch right on the thermal break, I stuck down a piece of filament so that it welded together, then just turned on the extsruder heater to remove the stuck filament.

Thanks to Paul Marson, a mate of mine who suggested using a pot handle, turned on an a lathe to produce a thermal break, any other plastic like PTFE or PEEK would have melted.

On Friday night, cause I really don't know how to use a lathe, yet, Paul turned out a piece of stainless steel tube that I got from the hobby shop a couple days before, 1/4 inch OD 0.049 wall, OD turned down to 6.0mm and ID drilled to 5.0mm as i'm currently using a MindKits stepper motor rated at 23Kg/cm or 2.3Nm.
Why turn down such a tube, was because to make up the bulk of a package from the US, IE the fiberglass nichrome wire, got some nozzles and a new gear wheel that does indeed grip the filament much better, at the same time, and another stepper motor all from MakerBot.

Reason this post is so, so delayed is because the minor iterations i've been doing are so minor that its not worth blogging about, and also, the recent package too over a moth on a 10 day priority post from the US.
I'm so angry with USPS, that they can't even read the address label properly, which clearly states New Zealand not Zealand in the Netherlands, so yeah, it went to the Netherlands.

A chat with MakerGear also revealed that I can get more stuff I require for the hot end from them, including Wade's Exstruder, if anyone wants one, plus their heat core looks very cool.
Right now, i'm out of cash, and visa is quite high after paying the quarterly bills as well.

I hope to have the extruder running, and post a video of the iterations i've gone through to get it to work, though current experiments show that I have the RepRap host set to 300 degrees and 275 degrees read from the thermocouple just to extrude PLA, but at least the fumes from PLA are much more bearable than Kapton tape adhesive, smell like burnt sugar. :)

1 comment:

  1. The temperatures to require PLA are around 190-220 degrees celcius. What's different about your PLA? I use Green Ultimachine PLA 4042D.