[ Closed ] Filament Extruder - Convert pellets to filament (Page 8 of 58)

I coiled up my first few meters, and will try printing it tomorrow.  It's running 1.73 +- .03mm. However it is a little wavy, so that if I measure on the thick part of the caliper it is 1.83.   I wonder if mounting it to the wall pointing down will help it extrude straight without the wiggle.   I had to point another bigger fan from the side.  It was staying soft long enough for the slightest movement to put a bend in it.  Cooling it faster right out of the nozzle helps it resist sideways motion.

Yes, still 50:1ish. One thing I do not like is that switching colors takes a lot of time and plastic to push out the old color. I am starting to think it might be better to go to a smaller diameter set-up with a faster turning auger.  This way, when I do a color change, new pellets make it to the melting area faster and there is less wasted material. Another thing I thought would be cool was if there was a way to change the hot end quickly if I want to extrude a different type of plastic (right now I think I'm stuck with ABS because of the different melt temps between it and HDPE).

I am still getting a small bit of contamination showing up in the filament. Dont know if it is from before or not but we might need to experiment with a screen to try and catch the larger pieces if it continues.

Diameter is consistent. I am finding that there are many factors that can cause it to change.

The problem with a smaller auger is that you need smaller pellets. The recommended pellet to auger diameter ratio is 1:4. I think we could make the cold zone shorter though.

You could waste less plastic by extruding until empty.

Oh, okay. Yeah I'm not sure that this could be avoided. You could slide the heater more towards the brass cap to reduce the size of the hotzone, but at the end of the day, you need about an 1/2" - 1" of molten plastic to ensure consistent extruding. The last thing you could do is move the auger further in, which would let you push more of the plastic out, but would increase drag on the motor. It's probably not practical to do frequent color switching.

I've redesigned it to use 2 flanges instead of 4, and a single longer nipple instead of two shorter ones. I plan to build one on the 2nd or 3rd, and send that kit to the next beta guys. It will reduce the part count and get rid of the flange misalignment problems.

I'm trying to simplify the electronics. I could get rid of one or both of the switches. I'd like to keep the fuse block, because along with the ground wire, they keep the chassis from becoming electrified in the event of a short. Thoughts?

The front nylon tie over the heat wrap started to melt and had to be removed.  I couldn't get the thermocouple to stay put with the included SS tie, so I used a small house clamp instead.

The electronics enclosure could not contain all the parts and had to take some tools to it.  Added side port for thermocouple plug, hole on top for ground wire and longer port on back for heatband wires, 3 prong power cable and 2 prong extension.

Making sure the 2 flanges that are back to back are flat is very important.  I recommend people with this version of the kit find the 2 best fitting flanges and put them aside for that from the start.

It took a good 15minutes to start extruding anything once I started the auger for the first time.

Ya I'm going to switch out the washers that came on the bolt with 2 of the washers on the motor support.  The other ones have a larger diameter and will help keep the filament on the brass.

I used aluminum foil because there's less friction plastic-metal than plastic-wood. Lowering the temperature helps too, but increases diameter and decreases speed.

Wow. cool project that is going on here..

Anybody wants to upload a youtube video or two of it in action?

New thrust bearings showed up, I can get back to extruding again...Thank You Tim!

Saw this on thingiverse, seems like this was the place to post it.

http://www.thingiverse.com/thing:30705

That is the next thing I want to build.  It might be tricky to dial in the speed of spooling vs. speed of extrusion, but I think the end result would be more consistent.