ExtrusionBot - Kickstarter

Here is another at home extruder.
http://www.kickstarter.com/projects/1622873957/the-fastest-filament-extrusion-bot-makes-abs-pla-i

http://www.extrusionbot.net/

 

Pretty cool!

 

So it comes with its own winder ? Thats nice
Given the fact that filament extruded ALWAYS at random rate (no matter what you do) does the winder takes that into account and adjusts its speed in order to avoid pulling or pushing against the filament effecting its diameter ?

 

Apparently not very well. I've had many customers tell me the only thing that made their ExtrusionBot usable was a Filawinder. Here's one such customer:

 

I can extrude 1.75mm filament at +/-0.05mm, without a winder. Is this not deemed consistent? It is the specifications all major suppliers advertise.

 

Wait. That thing sounds like a car starter ?

 

I tried all angles and heights. Going too high is no better then going too low.
Too high and gravity will pull on filament too much causing it to stretch and decrease diameter.
Too low will do opposite. It will add resistance encountered by exiting filament causing it go bent or bulge.

I had 2LB of ABS MG94 extruded at 4 feet (nozzle to floor) runing thru a polished metal loop (2 inches across) 1 foot away from the nozzle.
ABS curls nice and at 4 feet it could not get any better. You can even get down to 3 feet and half if your setup will allow to curl the filament at that height and nothing will get in the way.

Biggest factor to get 1.75 was to drill the nozzle with 1.8mm drill.
Went to homedepot and picked up $3.99 brass end cap in plumbing pipe department. Snap ring and a $3.00 filter (actually many filters) and you be good to go. (if u have that drill bit size)

For PLA 1.8mm nozzle wont work. It has to be bigger if using same height and same setup. 4 feet is MINIMUM and 5 feet MAXIMUM height that worked for me.
I think i had to do all the way 1.9mm for PLA. Cant measure that hole, it was drilled uneven with drill bit that was bigger and got tapered down on a bench grinder.

 

Too many variables.
There are few different ABS kinds. PA747 extruding from nozzle 1.8 at 215C produces good 1.75 diameter. I should really go lower on temp, maybe down to 190 but then i will need smaller diameter because cooler=thicker=slower.
MG94 does same but at 200C.
PLA is a completely different game. It takes 1.9mm nozzle, higher elevation and allot less temperature, like 170. Reason for bigger nozzle is is to allow faster flow. This is because PLA is extremely slow for extrusion. 2-5 inches per minute VS 23 on ABS PA747 (as per today test).

Temperatures and nozzle diameter are also effected by ambient temperature.


In other words, its a headache to get it right. But then driving a car isnt all just pushing the gas, it's got allot of other things involved.

 

I found it. Each formula is effected by what you stuck with. Its all about nozzle.
You can tweak the temp and elevation to a point where it gives you solid even diameter extrusion but wrong size, so all you gotta do is to resize your nozzle.
For example. If you stuck with 1.8mm nozzle and getting diameter bigger then you want, increase temperature and elevation. (just like i did last night switching from ABS MG94 to ABA PA747)
If you stuck with smaller diameter nozzle (1.6mm original) and cant get temps any lower and not getting diameter big enough, drill the nozzle. (Just like i did when i switched from ABS MG94 to PLA)

thats the formula. Only 3 components and nozzle is the major one.
Everything else is related to drying pellets prior to extrusion.