Very slow extrusion (Page 1 of 3)

GP35 does run slower (as it has a lower MFI, have you read the Polymer Extrusion sticky?), you need to increase temperature to compensate, but that will only help so much. What rate did you observe with MG94?

Things that increase extrusion rate:

Checking that the hopper is not obstructed and the cutout is within 20-30 degrees of vertical
Fully insulating the barrel
Increasing temperature

The video is fine, the motor clicking is not. How fast is the auger spinning, in RPM?

That's normal, I don't know why it would be clicking. It is possible your hopper isn't feeding pellets well.

I've been told that the effects of temperature, MFI, etc are non-linear in respect to extrusion speed, so a small increase in MFI can cause a big reduction in speed.  I have some clear ABS that is something like 3 or 4 notches above MG94 and I couldn't get it faster than about 3-4".min either.  Masterbatch can also slow down extrusion, even at the small ratios it gets mixed in.

I'd first try running horizontal with a normal hopper to rule out hopper feed issues.

You pulled the hopper and put on a standard one in 9 minutes? I'm impressed! Can you post a few photos of your current setup?

It's possible that a plug of plastic is stuck to the auger, and not sticking to the barrel (think of it like rotating a bolt with a nut on it, but the nut has no force on the outside and the threads are covered in bubblegum - the nut won't move on the bolt). If that's the issue, there's a three on it here:

http://www.soliforum.com/topic/6790/fil … -come-out/

It's only happened to me once and to a handful of customers, so its hard for me to troubleshoot.

Yup.

The next step is to heat to 190C or so, pull the nozzle, and pull all the plastic you can out with needle nose pliers. Reassemble, attempt to extrude. If that doesn't help, the options are do what I linked above, or buy a new barrel/auger.

I really wish I better understood what causes this to happen occasionally, but it's only happened to me once in over 1500 hours of running.

one of my many career fields in life was servicing Commercial restaurant equipment and this process seems like part hot glue gun (3D printer extruder) and part soft serve ice cream machine which use a partial auger with Teflon/nylon scraper blades for drum wall then a short pair of push props at end of auger to help force frozen product out when extruder is opened.

this design may need a few more trials to reach near perfection. maybe its been tried already if so never-mind but; one thing that may be worth a shot other than what I posted above might be either ending the auger right after entering the hot zone of tube, or if that dont push melted plastic out maybe only have a smooth center shaft from there to face of orifice to turn a2-3 bladed shallow pitch fan/prop to help push melted plastic out.

I'm just using my experiences to help bounce some ideas around to help solve a little bug. does any of that make sense?

Mitch

ice-cream machines use smooth polished stainless steel mostly for food grade easy cleaning with no left overs for bacteria.

but in our case any rough surface makes for hard to clear after shut off. plus if you shut down there is plastic left inside that sticks to auger then when turned on the heat cant penetrate to the spinning auger enough to remelt plastic stuck to auger, then pellets trying to feed in just jump back (clicking as they do) as auger spins but cant feed as much due to partial plug

After taking a few things apart and with a little finesse, this is what my efforts yielded:

I am going to try extruding again, and see if there are any improvements. I dislodged the thermocouple , so I have to wait until everything cools down to re-kapton tape everything up. Also, while I was at it, I checked to see if the auger or the barrel was bent, and they were not which was a relief.

Can I recycle this?

another idea to keep plastic closer to outside edge and heat would be use an auger with thicker shaft and shallower screw so all plastic around shaft stays hot enough to flow even after starting with hard plastic on it. kinda like how potatoes, meat etc over 3/4 inch thick never gets hot in center when microwaved. its insulated by its self

Food doesn't get hot in the center because microwaves can't penetrate tissue more than an inch or so. There is nothing cooling the center of a auger, so as long as you wait long enough for heat up before starting the motor, the plastic will melt just fine. It is possible that what causes the plug is a premature startup, then after the plug of plastic spins on the auger, there's too much clearance to grip the walls of the barrel. No idea if that's the case, though.

Custom augers are extraordinarily expensive, more than the retail price of a Filastruder.