[ Closed ] Filament Extruder - Convert pellets to filament (Page 22 of 58)

any pictures of the contamination? how bad is it? size?

Pretty bad and fairly large pieces. When I get home from work tonight ill take some pictures.

I did grind them but I am not confident it was sufficient, which is going to be my first step after I disassemble and inspect.

Some pictures, for Jon and others:  https://www.dropbox.com/home/Public/Fil … 20Pictures

I'm having better luck with the spooler.  Last night I set the extruder up on a shelf pointing straight down and let the filament drag on the table for a few inches before being taken in by the rollers.  The turning of the rollers doesn't seem to be consistent enough to haul off the plastic directly.   If it lands on the table first, then the only force acting on the extrusion is gravity and back pressure from what the filament lands on.   I had tried putting the extruder and spooler on separate tables and letting the filament droop between them.  The filament is too stiff however.  If you stop the rollers, the loop doesn't drop, it pushes straight back against the die.   As long as the rollers and extruder are in line with each other without any other force acting on the filament, the rollers will pull the plastic out.  Even if there is a bend, the pulling force will transmit through the filament around the bend as if it were on a pulley. 

What I will try next is setting them side by side so the filament passes over a couple of PEEK guides I'm making, land on the table, then make a 180 turn to the spooler.  Any variation in spooling speed will act on the position of the loop on the table rather than the plastic at the die.   

I have to run the roller motor at a pretty low voltage to get it slow enough, not far above the point where there isn't enough torque to turn it.  I could try a bigger gear and see if it becomes more consistent. 

The spool tension can be adjusted by controlling how hard the spool motor shaft rests against the side of the spool.  If it is light enough, it will slip when there is any tension from the filament, and turn again when the tension lets up.  Coordinating the speed of the roller is a little more difficult.  The loop provides a lot of wiggle room, but it just means that it will take more time for being out of sync to cause a problem.    I couldn't get the filament to press an endstop switch.  I can try making an extension for the switch arm to reduce the force needed to activate it.   That might also exaggerate the hysteresis of the switch so the motor can run a little longer, and not be so on/off.

That just looks awesome.  Keep us informed once you make a good amount and then make a print with the results.

I've only printed a small test to see if I could.  I could only get a few meters at a time before something would go wrong.  I'm sure it would work fine given an unobstructed cone of space under the nozzle, but I wanted to get something more foolproof done before I start making filament to actually use.  If I run out of store bought filament I might get a little more motivated.  Also going straight to a spool is cleaner and more finished.

It's not my design, it's from Thingiverse.   I'm pretty happy about seeing it through to completion though.  There are enough unfinished projects lying around.  I bought the acrylic spool from Protoparadigm.    It has the advantage of opening up so you can take the coil off to the side rather than unspooling.

It's Lyman's.  Here is a derivative thing I made with my tweaks, which links back to his original - http://www.thingiverse.com/thing:44262

Got my clear in today also. Ran about 100 grams of it, inspected it for contaminants. Didn't find any. I'll run more tomorrow.

Nick - I got nozzles in! I'll ship your beta upgrade kit, and Ian, I'll ship your pipe nipple. Jon - did you need an additional white spacer?

I have been running the blue thrust bearing for about 15 hours without a problem. Spacers do seem to help.

Sure. $10 will cover the pipe nipple and the spacers.