PLA extrusion + PEEK experience

Moisture in the filament will actually cause the extrusion to form bubbles and droop easier than dry pla.

I don't think the issue is dryness here.

It looks like your nozzle is trying to pass chunks of something else other than PLA.

You mentioned that you ran PEEK before, is it possible that the PEEK is purging out and plugging the nozzle while trying to make PLA?

Are you using a filter nozzle?

-Anthony

Tim

OP said in the oven at 60c for 6 hours. That is on the low side of temp and time, but sufficient enough to eliminate these types of issues.

My response was based on the machine being setup properly, but it is possible that the thermocouple isn't correct, although im not sure how you would read a higher temp than the extrusion temp of PLA if it wasn't touching a hot surface.

Are the components rated for PEEK temps? Meaning, if the OP used an ABS printed hopper and heat creep followed, it could lead to solid slugs in the screw at the feed throat causing excessive motor load with the lower temps.

Thanks for all the reply,

1. Thermocouple is mounted on nozzle(inserted into the small hole that on the side of nozzle). I can't use any tape to fix it since if I set temperature to 365, the Kapton tape would melt. So using Cu wire strand to fix it.

2. After assembling the second machine, I tried PLA first. It was stalling motor repeatedly. To check everything is assembled properly, I tried extruding ABS. I could do it at 190, although current taken by the motor is high. But I could hear motor struggling from the sound

3.To check if anything wrong with the assembly, I disassembled everything except auger(I didn't remove Auger from barrel since plastic was still inside). Oiled the Compression bearing, Reassembled it. Checked for movement of Hex socket. To make sure it has enough movement I even removed the plastic washer. Everything seemed okay for me. The thing I noticed is that, like with my first kit, Auger is not exactly aligned with Motor. I have already reported that when assembling my first machine. Tim told me that the Acrylic spacers may not be of all same thickness. So only change I made with this machine is 3d printed 4 Spacers(11.5 mm height) and used it in place of Acrylic spacer. Still there's a misalignment. I tried my best to reduce it as possible.

4. About purging,

This is how I so far run the machine,

Like I said, I tried PLA after assembling of machine, then ABS.
Since both of these require almost similar temperature for me, I set temperature to 230 degrees, waited until almost all PLA extruded, added ABS to hopper, waited for around 15 minutes at this high temp. Slowly reduced temperature to 190.

Then tried PEEK, extruded almost all of the ABS, increased temperature to 380, added PEEK, keep extruding it. It will extruder some kind of a mixture of PEEK + ABS for a long time, then peek only

My machine was in vertical set up until this. Since I wanted to reassemble the machine, I removed it from wall

I placed machine in horizontal table about 45 inch from ground. Reassembled it. Extruded ABS, still taking more current that I anticipated(1.5 - 1.75). After finishing all the ABS I had, moved on to PLA(Heated at 75 degrees for more than two hours, that was already dried around 6 hours before this drying) and put it into hopper directly. Waited until i get clear PLA.

I am using a similar oven to dry the pellets https://www.amazon.in/Bajaj-Majesty-16- … oREALw_wcB

5. In first machine, I made a hopper in Stainless steel  to handle high temperature. For this machine I haven't made one yet.

6. 180 Degrees for ABS was causing motor stall. that's why i increased temperature. Would it take more current for higher temperature or opposite???

7. One time when the machine clogged, I removed the nozzle and found that there's some peek at the barrel end. I removed it using a plier. To avoid any nozzle issue, I used another one. Not put in any filter so far with this machine. I made sure no plastic is inside the nozzle in the first place by heating it with a gas welding torch. I have ordered several drilled nozzles, I will try to drill a new one and test it.

Mine is similar to what this user had
http://www.soliforum.com/topic/16114/pe … the-auger/. I'm thinking about crushing the PLA to a more manageable size. I tried a mixer grinder, it didn't work. I asked help of a bio technology institute, and they said OK. So waiting for it.

This is my latest result, I could extrude continuously at 225 degrees. I'm not looking for quality of filament or diameter, just continuous extrusion with out motor stall.
Machine is in horizontal set up now.  But by looking at the filament coming out of nozzle(there's ooze), I won't able to maintain a dia of at least 1.5 mm when move to vertical setup.

There are several types of PLA grades on the market, mainly
3D870
3D850
4043D
4032D

870 requires a but more power to extrude due to its flex modifier.
850 is basically a clean version of 4043D, but slightly harder
4043D / 4032D is basic PLA that typically works with everything.

There are also other manufacturers of PLA, but typically not in the USA.

One thing that keeps me wondering, what is the no load amperage?

Yep, you are correct.

Most of those grades aren't used widely in standard compression extrusion of 3D monofilament though due to their MFI properties and brittleness.

Many of those grades are used in thin film forming and bound with cellulose to accelerate the biodegrade process.

Most 3D filament manufacturers start with a base of that material then add modifiers via compounding and/or plasticizers. I suppose that is a moot point since the OP doesn't know the grade.

Tim, what is the typical no load amperage of the extruder?