I think that has a mistake, you probably meant increasing f_s decreases pressure

So barrel needs to be high friction, and screw low friction, to get maximum pressure.
So if there is heat up in the barrel, this increases friction (how does it increase friction, more surface area as softer plastic, almost molten?) which does increase pressure in the main melt zone (just above nozzle), or in otherwords, would help in moving the pellets and extruding them.

a defensive and passive-aggressive approach

I am not being defensive, I am trying to help by examining the chain of events in order to arrive at what changed. I have run Filastruders for thousands of hours in total, I am just trying to share that experience. For example, regarding your comments about friction - it is the friction between the polymer and the barrel that I am referring to, not the auger touching the barrel. The importance of this friction is explained here. Glass fiber is extremely abrasive, here is a link on just how little material was needed to significantly impact the surface finish.

Anyway: it is clear my input is not wanted, so I'll kindly step away from the topic.

I only put a small hand full of the reinforced nylon, that amount cannot in any sense in this universe polish the barrel. All i wanted is to see if it would work as is. The granules were oddly shaped too, like 1.75mm filament in few mm long strands, weird.

The instructions: There was something in this regard not to be sure which way. That's all i can remember, it's a long time since that.

Heat higher up: There is a big gap between barrel and auger. I would not expect thermal expansion to be so high that they would start rubbing. So how exactly would friction increase in such a meaningfull way the motor cannot handle it, if it works now?
*THIS* Also is unrelated to this nylon issue, i've been considering adding them earlier but what Tony said made me revisit this thought.

My heater band is as close to the nozzle as possible.
What i could see of the pellets just circulating and not moving down, they were completely solid at the intake, it's not that hot high up there.

Is it beneficial to have that described pre-melting zone, if i add another PID to adjust that separately?

Seems to be what i have going on, it seems ZERO pressure @ nozzle
It was extruding fine some ABS, but i needed to do PLA. Just had a shipment of reinforced nylon so i decided to give it a go first, assuming nozzle will clog ... Which it did maybe ... Extruded a bit fine and then ended. Took out hopper (breaking it in the process .. sigh), and pellets was just being circulating at the same spot.

Glass reinforced nylon is very abrasive, it may have polished the inside of the barrel which would reduce pressure in the melt zone.

There may be a clog upstream, I would recommend removing the auger from the barrel to inspect.

How are the instructions badly worded in this regard? They state that 2-10mm of the auger is to be sticking out with the thrust bearing compressed. How can this be clearer?

I and others have achieved tolerances +/-0.05mm or better without a winder. It is important to ensure the filament has a clear path to the floor, unobstructed and high enough that the bend radius of the filament is not severe.

Assuming the barrel is undamaged, more heat is not needed and will only serve to load the motor further by creating more friction. Step through things logically - was working fine before reinforced nylon was added, so think about what occurred then - possible abrasive wear from the glass fiber, possibly extruded at the wrong temperatures and stuck to the auger.

Try to relocate it up and down (or left and right if you extrude horizontally) to see how it effects the flow.

Insulation is very important.
You want to create [pre-melting area] going toward the motor as far as possible. It will make pellets soft before they reach the hottest part, causing them to be more pushy all the way.

Heat can be the issue.
Its not too hot or too cold, its simply not enough heated area.
I doubled my speed when i insulated the barrel completely.

The reason for this is because at the tip, pellets are melted and before the tip they are not. So when solid pellets push into the soft melted plastic at the tip, they dont provide much pushing because plastic in front of them is too soft to resist (and exit as a result) so pellets keep circulating around the same area and exit at almost no pressure.
.
Go on ebay and find cotton heat insulation sheets, similar to those used for 3d printer nozzles except they have no tape on them.
http://www.ebay.com/itm/252192215192
Then wrap the entire barrel with that insulation, few layers.

When you insulate the barrel, you create more pre-heat area. This softens the pellets before they reach the tip. The soft mass is moved by the screw much more effective then that same screw moving solid pellets.

Cotton insulation will be more stable then the piece of garbage that comes with the kit.
It will last longer and it will not be as messy or become brittle as fast and shed fibers etc.

Seems to be what i have going on, it seems ZERO pressure @ nozzle
It was extruding fine some ABS, but i needed to do PLA. Just had a shipment of reinforced nylon so i decided to give it a go first, assuming nozzle will clog ... Which it did maybe ... Extruded a bit fine and then ended. Took out hopper (breaking it in the process .. sigh), and pellets was just being circulating at the same spot.

Nozzle out, scrape all that i can off and leave the motor running while cleaning the screen, put back, extruded half a meter maybe and stops again

I have insulated the whole barrel (header wrap), and even tried much higher temps. Top of the barrel where hopper is luke warm ... Maybe 40C.

When taking out the nozzle it felt like there was no pressure at all

I wonder how much does the screw distance from nozzle affect this? I think i got this wrong due badly worded assembly instructions and only realized this after assembly done - seemed to work fine so ... Bad instructions btw: It should be noted that filawinder is basicly a must have. I never succeeded making usable filament before getting filawinder.

If i add heating elements on the base barrel as well: weld in drilled hollow M6 extension nuts *2, and use hot end heater cartridges up there, first in series so 40W total, and move to parallel for 80W total if more needed.
Would that help? Basicly melting the plastic before exiting screw.

Even v1.5 should be producing 1kg in ~10 hours, not 60.

What ABS are you using?

I'd also expect a 2mm nozzle to make 1.90-2.0mm filament, not 1.75. Something strange is going on here.

Hi - thanks for that - very interesting.  I wanted to increase the speed so I drilled out the nozzle to 2.0mm and was running it at 195°C with a larger loop to the filawinder so there was more tension/stretch on the filament coming out - a bit of fiddling/balancing with temp and loop distance made it 1.75mm fine.

I am not using the MG94 pellets, I am using 'high flow' ABS pellets from here:  http://www.my3dmedia.com.au/collections … bs-pellets .  I am told that these pellets are not quite as fast as MG94.

I just received my 2.0 motor and stall control PCB today.  I have installed it and am producing filament MUCH faster now.  The motor stays at a constant speed too - very nice.  Previously I was getting a slight slowdown when the heater went on.  I thought it might be the power supply so I used a beefier 12V supply - but it didn't make any difference.  I think the 12V supply wires inside are too thin and there is a voltage drop due to the current.  Anyway, the control board solves that.  I see on the display it is dropping from 12.1V normally to 11.6V when the heater is on, but the motor now just chugs along constant.

I NOTE that the motor was NOT a straight swap.  The square shaft out of the gearbox was a bit shorter and wouldn't reach the coupling - so I had to take the gear and shaft out of the old one - didn't want to open the gearboxes but was kinda desperate.  I note that the legs on the new gearbox are slightly shorter so the back end of the (old) shaft actually pokes out a bit - so I had to drill out a hole to make space for it.  Anyway, extending some cables etc and it worked.

I adjusted the CV CC pots on the board per the 2.0 instructions - I hope I did it right.  It's working anyway.  I'll get some of that header wrap - I'm pretty sure I need more insulation.

What ABS are you using?

I'd also expect a 2mm nozzle to make 1.90-2.0mm filament, not 1.75. Something strange is going on here.

What kind of feed rate is expected?
I also think my Filastruder is too slow.  It takes more than a day to do 500g.  I estimate it will take 3 days to make a 1kg reel.  I am running it at 195°C through a 2mm nozzle to make 1.75mm filament.  I have checked the screen inside the nozzle is clean/clear.  I have tried a better hopper design to ensure the pellets are feeding into the barrel well.  I don't want to up the temp much more as filament quality will drop.
Is this rate normal?  I don't have any reference for 1.75mm filament.

I finished a 1kg reel of 1.75mm filament - it took 60hours.  I tried a more beefy 12V supply because I thought it may be dropping Vs when the heater goes on and the motor slows down - not the case.

Thank you for your suggestions.  I think my issue is a combination of two main things - the barrel is not insulated enough and I have an old v1.5 motor.  I have just ordered a v2.0 motor with a speed protection PCB.

For insulating the barrel, I just got the foam/foil wrap that came with my v1.5 - it really only just covers the heater and nozzle.  I see the v2.0 has a much bigger blanket.  Can someone point me to where I can get a good piece of that stuff?  I can't find any on eBay apart from car heat/sound insulation and also car exhaust insulation - would either of that do?

http://www.soliforum.com/topic/7551/che … -diy-1418/
Make your own CHEAP nozzles.
That filter is too fine, thats why it sucks.
Use filter i show on my post above, its effective and no pieces big enough to jam extruder nozzle pass thru.

The stock melt filter nozzles do not "suck", they have 250 micron filtration because 0.25mm nozzles are very common in hotends. If you pass particles that are larger than 250 microns, you will clog the hotend.

However, I can't manage to change it. It doesn't have its retaining ring (the spare filters do have it); it seems it's just glued to the nozzle.
Does anyone know how to change it?

Soak that nozzle in Acetone.  It will disolve the ABS and allow you to get the filter out and clean off the debris.

-os3dp