Originally shared by Thomas Sanladerer
As it turns out, i can make any size filament from 3.1 to 0.5mm with the 3.2mm nozzle! Even without the optical measurement and feedback loop in place, the diameter is already pretty consistent - i’m getting +/- 2% on the cross-sectional area when everything’s running smoothly. And as long as i get a bubble-free stretch, which mean that i’ll have to keep my pellets in the dryer longer than i anticipated.
Did you build this, or was it a kit ?
Did you try to use a kitchen Food Dehumidifier ?
I use one to dry and ‘de-coil’ tightly wound filament.
Paging Doctor @Thomas_Sanladerer !
Does that mean you can recycle used filament?
I don’t know guys, that looks an awful lot like a weapon…
@Daniel_Osborne I wouldn’t suggest reusing filament, the plastic degrades just like in injection molding. Generally, in injection molding there is a maximum percentage allowable of material that can be reground before you’re just shooting garbage parts. Given the time investment, I wouldn’t think it would be worth it to print with recycled filament. From looking at matweb, it appears that 3d printing is done at similar temperatures to injection molding.
Although @Eric_Moy is right about the pitfalls of re-using filament, I have aspirations to use scrap filament for infill purposes where you’re less bothered if it’s a bit bubbly or whatever. This may come to nothing but I’d like to re-use all the failed prints and redundant parts I’ve got squirrelled away.
You can have a mix of virgin pellets and recycled material.
And kudos on the design. Stretching the filament is actually a pretty accurate way to set the diameter.
Ok, let’s answer some comments * cracks knuckles *.
@Shachar_Weis The whole extruder is 100% designed and built by me (ok well, maybe got inspired on using an auger bit by Layman’s extruders). Every part was either milled, turned, printed or soldered right in that workshop, except, obviously, for bearings, motors and such.
I’ve built a temperature and humidity-controlled dryer a couple days ago that is probably fairly similar to one of the food humidifiers - see https://plus.google.com/101189457349966331973/posts/Sq3MRzyH8wJ
It does dehumidify the pellets, but it takes some time for them to dry through.
@ThantiK if i had known this post would get that kind of publicity, i would have made a nicer one…
@Daniel_Osborne , @Eric_Moy , @Tim_Rastall i’m not considering using recycled prints, since virgin pellets are only around 2-3€/kg. I’d also have to build a grinder and deal with varying quality of the plastic, which does not seem worth it. Also, one can buy regenerate or shredded and sorted recycled plastic for about 1€/kg, which the extruder should be able to turn into filament (albeit of uncertain quality). I do want to try that at some point, but for now i still have that nice 25kg sack of Polylac 747 that i’ll use up first.
@Jason_Gullickson i don’t know why, but pretty much anything i build ends up looking like a gun or a bomb!
@Stephanie_A thanks! It took me a fair while to get all the concepts worked out, and i’ve so far had at least two or three failed designs for each of the components that now work.
Oh by the way - Dear NSA, did i just make it on to your watchlist by using auger, pellet, shredded, 747, gun and bomb in a single post?
Fantastic! I was actually just brainstorming this week on how I could find a filastruder that can do both (smaller .5- 1mm diameter filament) and reliable diameter consistency, to improve resolution goals!
Will you make this into a DIY post or a kickstarter? 
@Steve_Sharp Doing a Kickstarter is just so much work to get it right and i have so little time… But since i’m relying on FOSS projects myself, i will document the individual components in the coming months and make plans available.
The community would benefit greatly! Much appreciated, mate. Time consuming it is, but I think with a lot of the individual communities support alone, you could do it. What it looks like is just get enough word out when its ready and business model is setup and you should be able to fly. I would definitely support if it can reach the specs you mentioned.
@Tim_Rastall that a pretty clever idea, didn’t think of that. If you do mix in virgin pellet with recycled scrap, be sure to mix it up all uniform. Pretty cool
@Steve_Sharp don’t get me wrong, but I have very little interest in making money by selling extenders - a full kit with everything you need to reasonably make filament would probably be around 700€ anyways. However, I am thinking about selling filament, all I’d need for that would be a distributor and / or a bunch of resellers - @Nils_Hitze , you’re an hour away from where I live and Munich / Hallbergmoos is part of my regular commute anyways, would you be interested in having a supplier of Made in Germany filament?
<3 to - you’ll be at #OS3DC ?
Nope, won’t make it there. But i did hear that it’s going to be pretty awsome!
hehe - true. Let’s talk next week after the event.
This is excellent work! I was thinking about making a puller and small water bath for my Filastruder since the coild on the floor method is a bit archaic.
The only constructive criticism I have to offer is related to the dryer. A good industrial dryer uses hot air AND desiccant. If your ambient air has low humidity then it’s not a big deal. However, blowing hot air over plastic can actually increase the water content if the air carries enough humidity. This problem is often seen when Asian companies injection mold parts. Many times they do not have dew point controlled dryers with desiccant. The ambient air in such facilities is often highly humid. Therefore, when they “dry” the pellets they are actually increasing the water content. Not only does this lead to surface defects, but in some plastics this can actually lead to hydrolytic degradation of the polymers when the material is heated in the barrel.
@Ben_Malcheski thanks for the advice - i have a dehumidifier sitting around since my basement’s air is generally way too moist. The idea is to make another air-tight box that will house the dehumidifier and the dryer box so that the dryer is already fed with dry air.
Awesome work @Thomas_Sanladerer ; jokes aside, some very cool and well-thought-out tech.
