Very slow extrusion (Page 2 of 3)

The melt filter is on the inside face of the nozzle, under the heat band.

Letting the barrel get warmer normally helps flow.  The pellets need more friction against the barrel, and less on the screw.  If they drag more against the barrel, they will tend to slide along the screw.  Similar to if you spin a bolt and keep the nut from turning, it will slide down the bolt.  The pellets get a little stickier as they warm, so that helps with the drag against the barrel.

It could be that the auger isn't smooth enough, or the barrel isn't rough enough.  Maybe replace the auger and see it that makes a difference, then replace the barrel if it didn't.  Most pipes that you buy have a seam down the inside, but the Filastruder uses pipes which have the seam ground down.  I wonder if some of them get ground smoother than others, and if it is enough to affect the flow.

What is the highest speed you've ever observed? When did it happen (how many hours into use)?

Have you tried increasing temperature? 185C, 190C, 195C?

I'm sorry this is a pain, I'm trying to collect data on something that happens very rarely so I can understand it better.

No, not fastest you see now, fastest you've ever seen while using your Filastruder, and how many hours (roughly) did it have at that point?

Wait, so the fastest you've ever seen it run is 6"/min, and that's happening currently, after around 100 hours of runtime?

That tells me something has been wrong from day one then. When you assembled, with the thrust bearing compressed, how far out from the end of the pipe nipple did the auger stick?

Do you see improved speeds at 190C or 195C?

Yup, that's correct.

After you check speeds at 190C and 195C, the next step would be fully insulating the barrel. You can do this with a washcloth for now. If that doesn't help, then it might be time for a new barrel or auger, probably barrel I'd guess.

12-15"/min. Some users report north of 20"/min.

Have you tried all of the above? What were your results?

I saw a pic somewhere on here of auger and it looked like lots of rough places to grab plastic. its just a large ship auger drill bit which are made by several companys with different tooling some smoother some with thicker shaft and shallow ribs/fluting than others and prices are all over from cheap to way over $100 for these large ones. the objective here is for the auger to just feed pellets through and out as sized plastic string fast as can be done properly without melting back to hopper or sticking to auger. while filtering particulates and not burning plastic. so the better we determine problem the less expense wasted fixing it.

Thanks for the info.

For me the problem was that the plastic palettes were not flowing into auger freely. constantly shaking the pallet holder helps. We put a small vibrator to fix this issue.

The vibration motor is only needed for vertical hoppers.

I assure you the shape of PLA pellets is not an issue. I have extruded PLA quite fast, though tolerances were not good. What temperature are you extruding at when you find the extrusion is slow?

http://www.soliforum.com/topic/4108/my- … s-and-pla/

6ipm with PLA due to running lower temperatures. Note that he had a different model temperature controller, 140C on his controller is 155-160C on ours.

The ABS I ship with kits is optimal because of its MFI, not its pellet shape. Search the internet, you won't find anyone complaining about the shape of pellets.

Stand on the shoulders of the giants that came before you...

What kind of diameter are you getting at 190?

Is that on the larger nozzle? I'd back it down to 185 or so to keep your diameter variation in check. You shouldn't give up much speed, maybe a few ipm.

You can get fiberglass header wrap from Amazon, or pipe insulation like what I send with the kits from McMaster.

Glad its working out