1 Topic by Weekend Avenger (edited by Weekend Avenger 2014-08-15 09:09:53)

  • Weekend Avenger
  • Member
  • Offline
  • Registered: 2014-06-17
  • Posts: 181

Topic: A beginners adventures in filament extrusion

Hi all,

Just wanted to post some random thoughts about extruding filament made with the Filastruder. Unlike most, I decided to attempt extruding Lustran 408 ABS from the very start of my machines assembly. My reasoning is that while I may lack a considerable amount of knowledge on how to do this, the plastic was extremely cheap and so I could afford to waste it as a learning experience.

Lustran 408 is a "medical grade" ABS injection mold plastic. I can only speculate on why I was able to get it cheaply, but the most likely cause is something happened to the plastic that removed any possibility of selling it for "medical" use, though in the end the reason doesn't matter.

Lustran 408 turns into a gray kind of plastic when turned into items / filament in its "natural" form, though the pellets look white. Its melt flow is considerably below Sabic's MG94 which gets included with the Filastruder (still saving mine for later use) which I can tell by watching videos of others Filastruders pumping out filament at a much higher speed than mine does. The Lustran 408 is also worse warp wise than the stock XYZ filament and much less friendly on temperature selection. One last bizarre property it has is a much higher resistance to acetone than the XYZ filament does.

With that last paragraph in mind, the stuff does extrude nicely even if slow. The filament is easy to get to size and has a nice smooth finish. It does have a fairly nasty downside, which is that it is VERY hard to spool after you've let it pile up on the floor. I've heard mention of spooling with a drill later, which isn't going to happen with the Lustran 408. Even attempting to hand spool it, it tangled so badly that my last attempt turned into a two hour fight and I ended up with 2 partial spools and a bit of loose in a roll due to being forced into cutting the filament because I simply couldn't get it untangled. This is probably my third long "run" with the Filastruder with the Lustran 408 and due to the problem of attempting to get it on a spooler I purchased and am assembling the Filawinder.

But I thought I should show some of the finished results with the Lustran 408, so here are my Filawinder parts. They were in some cases sanded, all were slightly vapor smoothed (Lustran 408 doesn't work well with that) and that small gear was a nightmare to get printed.

http://i.imgur.com/oZ7tg96.jpg

2 Reply by titaniadioxide

  • titaniadioxide
  • Member
  • Offline
  • Registered: 2014-06-10
  • Posts: 37

Re: A beginners adventures in filament extrusion

Did you use this for the 8 hour purge at the beginning?  If so, the point of the purge is to get the nastiness out of the inside of the barrel, which turns the extruded filament grey.   This filament probably shouldn't be used in the 3D printer.

Also, it's a really good idea to use the provided ABS to make sure that your Filastruder is behaving as expected.  You can't know if the slow extrusion is from a different melt flow or because something is wrong with the Filastruder when you use a different material.

3 Reply by IanJohnson

  • IanJohnson
  • Moderator
  • Offline
  • Registered: 2012-08-07
  • Posts: 2,815

Re: A beginners adventures in filament extrusion

MG94 will turn grey if you get it too hot, somewhere above 200C.  I wonder if you exceeded the equivalent temp for this one.  Going cooler will of course make it extrude slower.  Also if you heater band is too far back from the nozzle, it would be heating the plastic more than you might expect to hit the desired temp at the nozzle.

4 Reply by Weekend Avenger

  • Weekend Avenger
  • Member
  • Offline
  • Registered: 2014-06-17
  • Posts: 181

Re: A beginners adventures in filament extrusion

titaniadioxide wrote:

Did you use this for the 8 hour purge at the beginning?  If so, the point of the purge is to get the nastiness out of the inside of the barrel, which turns the extruded filament grey.   This filament probably shouldn't be used in the 3D printer.

Also, it's a really good idea to use the provided ABS to make sure that your Filastruder is behaving as expected.  You can't know if the slow extrusion is from a different melt flow or because something is wrong with the Filastruder when you use a different material.

Yes, I used the Lustran for the barrel purge and threw it away. I currently have a melt filter installed but the filament doesn't actually look any different than it did from the start and I am easily over 8 hours runtime at this point on the Filastruder. You have a good point on using the MG94 so I'd know that everything was working right, at some point I will run that through after my winder is up and running and see how differently it works.

IanJohnson wrote:

MG94 will turn grey if you get it too hot, somewhere above 200C.  I wonder if you exceeded the equivalent temp for this one.  Going cooler will of course make it extrude slower.  Also if you heater band is too far back from the nozzle, it would be heating the plastic more than you might expect to hit the desired temp at the nozzle.

I honestly have no way to know on the temp thing. The heater band is where it should be and my Filastruder should have a lot of insulation since I wrapped all the insulation and half the barrel with silicon tape. I did have to up the temp to 192 to get the size where I wanted it on the Lustran if I ran the Filastruder from the top of my stove. I did test once from the top of the refrigerator which did make the Filament smaller (so I could have lowered the temp) but it makes it kind of a pain to get a beverage refill then wink. I do know on my printer the absolute lowest temp I can get the Lustran to print at is 185, but the feed rollers will click if I try it. 195 seems to let it flow properly on the printer, but the "norm" for XYZ's filament on mine is 200, so the Lustran isn't that much different.