IanJohnson wrote: The other problem was that when I was trying the sensor at the nozzle, the winder was further away. That created a very shallow angle to the loop
YES! We figured out the Trick / Solution was to start a bit further away (13cm) during the 'loading/prime phase' and THEN move it closer to it's current super close (4cm) 90 degree incline position once you can pull on the filament from the other size, (see instructions diagram earlier). - This trick makes this setup possible and it works so well now!
IanJohnson wrote: whenever I go above 220 with MG95, I get gray filament. The gray tends to hang in there and has to be purged as if there had been masterbatch. Have you seen this effect when extruding at such a high temperature?Also do you think printing a pcb enclosure from conductive ABS would protect it from the static buildup at the spool?
YES we had this very same problem! We Discovered it was due to:
1) Masterbatch residue/grafitti ; Masterbatch acts like Crayon / chalk and the masterbatch/ABS soot coats the walls inside the shaft. creating a layer that doesn't flush and affects extrusion speed.
If you take a masterbatch pellet, you'll notice it's like pencil or crayon. you can draw on walls with it like a pencil....
And That's what happened inside the shaft for us, this thin layer. Signficantly slows extrusion at high temp. sometimes filament won't even extrude at all.
2) Horizontal filastruder. (no gravity to help move the pellets to the nozzle. due to masterbatch grafitti contamination on walls
The Confirmed solution was to put the filastruder on a 45 degree incline and remove the metal shaft and auger and put them under a blowtorch and BURN away all the masterbatch and plastic till it was red hot and completely brand new, then let it cool. Fire cleaning WILL solve the problem. You cannot just flush masterbatch Grafitti with ABS, it's not enough to remove the oxidized (Super hardened ABS soot) There will be residue buildup and immense wastage for the flush. We spent 4 days and 2KG Of wasted ABS flush figuring it out the hard way. Do not make this same mistake You really MUST use fire/blowtorch to clean it out, and it will become as good as new- I vouch for this method 100%.
After that, it flows sooo smoothly at any temperature from 180 to 255°C.
We don't use masterbatch now. (we use CMYK+W pre-coloured pellets and mix them... so easy now to get perfect smooth colour.)
IanJohnson wrote:The biggest challenge I've had with a short loop and keeping the sensor right by the nozzle is twisting.
Yes we had that issue too a few months ago with Masterbatch. We solved it by moving the sensor within 1cm from the nozzle and boosting the temperature to the manufacturer recommended extrusion temp so it stays soft enough for gravity to keep it down, so the twisting left and right doesn't affect the sensor as much as long as it moves down. We fire cleaned the die and shaft and don't use masterbatch anymore so we don’t have this issue.
We discovered something FAR better than masterbatch
We buy CMYK + white "precoloured pellets" and mix them like printer ink. It's soooo even and smooth now. We will never use masterbatch ever again! masterbatch is too tricky, jams and the ratio is too small for even mixing in the filastruder.
CFTechno wrote:Thank you for the amount of work put into this! Did you also measure the width fluctuation with this new short loop? How long did you run it in this short loop setup when measuring the temperatures? Because with the filament entering at 132C the tube might warm up rather fast and the filaments temperature might drop less at longer runs as the tube starts to warm up?
Thanks, happy to help. We measured the temps after 6 hours. We've been running this mod for 4 months now perfectly.
Re: Widths
There is no width fluctuation for us, but there is die swell expansion, The thing is, we use so many polymers with different swells, we decided to just use CURA for the .gCode generation, so every time we change the spool, we just update the filament width into the software settings. Takes 3 seconds and we're done.
Permanently solved all swelling and width issues, forever....
Reason: We find it smarter to change software settings in '3 seconds' to suit the filament, than spend hours getting exactly 3mm on the filament. This is because we extrude EVA, ABS, PC, PCABS , all with different swell and expansion rates. So there's no point trying to get exactly 3mm (at least not for us anyway)
An analogy would be like "shoe sizes". Easier to accommodate shoes of different sizes than force everyone's feet into one size.
tonycstech wrote:So going hotter gives more extrusion rate allowing for small loop or you spin the motor fast too ?
Hotter means the filament loop stays soft and sags, so this sagging triggers the filawinder sensor easily without problems. (previously the hard filament would just hang there without dropping enough to trigger the sensor.
The key is to keep the filament hot and soft so it can 'droop' and trigger the filawinder sensor. Cold / Hard loops often lock in place due to ambient temperature changes and don't move at all so the sensor sometimes doesn't pickup and it clogs and jams at the extruder. Hence the benefit of this mod is more suited for filawinder users who have all but given up.
elmoret wrote:The "anti-split bar" is not a great choice. That would transfer thrust to the motor
Thanks for the tip ! Yes I agree, there's little force on the motor with the central bearings, but the other issue was gravity since we're using it at a 45 / 90 degree incline, the lone centre wood block has to support the entire heavy setup and heavy hopper+ shaft+auger on it's own at an odd breakneck angle. That's the other reason it separated. Also the centre bearings aren't reliable for us due to the constant expansion and contraction from heating cycles and it gets loose and slides often, once again putting pressure on the motor.. Ours got damaged during a cold extrusion and it's been modified and disassembled multiple times. So like an Old pensioner, ours needs a walking stick, so to speak so it doesn't break its back.
Hope this helps.
Not long till the filastruder/winder is perfected! 
