I3 Pro B Filament Feeder problems - WARRANTY

[palad0n]

OK. Was working OK for a while. Got rid of the Z wobbles - cut away the restraining mounting holes of the top brackets. Got rid of the arcane clips for the glass bes top - double sided self adhesive thermal strips. Added the auto bed levelling advantage using the BLTouch probe. Set aside a morning to do full calibrations. Got X, Y and Z easy. Many thanks to the network of help out there. Started doing the E cal.

8 hours later still trying to work out WTF is going on. I've done unclog the nozzle (numerous times), complete disassembly of the extruder mechanism, tinkered with the driving voltage (the 0.8 to 1.2V DC thing). It still will not extrude sufficient material. Mark 120mm, set to extrude 100mm. Note the shortage, calculate new feed rate, set and redo. It just keeps climbing - as in I'm up to 150 and it still does not extrude 100mm. Forcing the feed(pushing) helps - but not with calibration. Manual forcing the feed, sans no stepper motor drive, shows a marked improvement. But at days end the extruder system is F'D. It is, afterall, a really basic system - as compared to some I've viewed on the net. A (brass) gear engaging with the filament pushing against a pulley. There is, however, NO system to adjust the force between these two devices. Tightening the screw, IAW GEEETECH advice, is superfluous . There is NO mechanism to move either the pulley or gear to or from either one, if so facto, NO means to adjust regulate the compression/force between these two MOST important element in feeding the hot end with material.

Assuming the GEEETECH people do monitor these forums, I do hereby claim warranty for a failed extruder feeder. IT has only being a month or so since I received (and assembled) the printer.

BTW, is there supposed to be a real difficulty in pushing the filament into the "melting" chamber? I have found (since I started using the printer) that I need pliers to really push hard on the filament to get it into the teflon feed hole. That and if the filament has a tendency to curl one way ( as it does coming off a reel) it can also end up curved around the pulley away from the the "melting pot" entry hole. And unless I can finally force the filament (or de clog rod) through the PTFA hole, the feed motor just turns happily with NO grip whatsoever.

I await with eager anticipation for responses.

Don Harris

[William]

OK. Was working OK for a while. Got rid of the Z wobbles - cut away the restraining mounting holes of the top brackets. Got rid of the arcane clips for the glass bes top - double sided self adhesive thermal strips. Added the auto bed levelling advantage using the BLTouch probe. Set aside a morning to do full calibrations. Got X, Y and Z easy. Many thanks to the network of help out there. Started doing the E cal.

8 hours later still trying to work out WTF is going on. I've done unclog the nozzle (numerous times), complete disassembly of the extruder mechanism, tinkered with the driving voltage (the 0.8 to 1.2V DC thing). It still will not extrude sufficient material. Mark 120mm, set to extrude 100mm. Note the shortage, calculate new feed rate, set and redo. It just keeps climbing - as in I'm up to 150 and it still does not extrude 100mm. Forcing the feed(pushing) helps - but not with calibration. Manual forcing the feed, sans no stepper motor drive, shows a marked improvement. But at days end the extruder system is F'D. It is, afterall, a really basic system - as compared to some I've viewed on the net. A (brass) gear engaging with the filament pushing against a pulley. There is, however, NO system to adjust the force between these two devices. Tightening the screw, IAW GEEETECH advice, is superfluous . There is NO mechanism to move either the pulley or gear to or from either one, if so facto, NO means to adjust regulate the compression/force between these two MOST important element in feeding the hot end with material.

Assuming the GEEETECH people do monitor these forums, I do hereby claim warranty for a failed extruder feeder. IT has only being a month or so since I received (and assembled) the printer.

BTW, is there supposed to be a real difficulty in pushing the filament into the "melting" chamber? I have found (since I started using the printer) that I need pliers to really push hard on the filament to get it into the teflon feed hole. That and if the filament has a tendency to curl one way ( as it does coming off a reel) it can also end up curved around the pulley away from the the "melting pot" entry hole. And unless I can finally force the filament (or de clog rod) through the PTFA hole, the feed motor just turns happily with NO grip whatsoever.

I await with eager anticipation for responses.

Don Harris

Hi，Don
Would you mind attaching a video to show me how this works?I'm so curious about it.
Besides,have you already read this post before？:
http://www.geeetech.com/forum/viewtopic ... 19&t=17097

[anderss90]

I am having the same issue. When i tried to calibrate the esteps, i saw that the filament did not move smoothly downwards. It was stopping and going. (Check this by making a mark on the filament with a pen).
I was also frustrated about the lack of tension adjustment between the driving wheel and the idle wheel.

The extruder i have is http://www.geeetech.com/new-mk8-extruder-p-998.html one ("New MK8")

I made a hacky solution to the problem by wedging something in between the tension thing.



This is not an ideal solution at all, but i have seen improvement on the extruder feeding. I also saw a smoother feeding at 220 degrees compared to 200 degrees.

[palad0n]

OK. Today I totally changed feed rates, etc and repeated print of a design that required small detail - using the 0.2mm nozzle. There were still problems, Basically, the feeder worked OK until there was a need for retraction. In Slic3r this was set at 3mm and 40mm retract speed. I noticed that the mark went up, back and up and back - but each up was higher than the last - that is there was no more filament feed. Experimented with these elements. Retraction, 1mm and 10mm.sec worked a treat. I ended up with, finally, a rather great output. While I still have very serious engineering doubts about the supplied feeder with no ability to adjust either the tension or cog positioning, I have been able to adapt it. In short, the originally provided filament feed system is seriously deficient in future performance. The fact that it failed my expectations less than 2 months into my 3D printing experience is symptomatic of a number of flaws with this GEETECH printer. Yes, I have spent a further $au15 in replacing this feeder mechanism - through GEETECH online store. But should I have needed to do so? AFAIC, this is essentially a warranty issue - I have paid $ for something inherently wrong that 'lived up to its failure' within 2 months.

Any hows, hopefully the pics will attach this time around.

20160722_231904.jpg (56.15 KiB) Viewed 20311 times

20160722_231805.jpg (67.36 KiB) Viewed 20311 times

[palad0n]

Learned - ensure filament is mostly perpendicular to entry hole. Use someones thingy from thingiverse www.thingiverse.com or design your own. Am currently designing a filament holder for both RH and LH sides. In progress. A few nails yet to hit before it is a goer.

[palad0n]

Seems a previous reply has gone astray. To the nub - the feeder mechanism supplied with the kit has no force adjustment - just a spring. Said spring being redundant as the lever arm it presses against has an end stop. I filed this end stop to try and increase the tension. It worked, sort of. The feed rate was still HIGHLY variable. I recently had the feed rate set at 266 and still failed to achieve 100mm feed. But when I physically pushed up on the lever, the feed rate dropped back to below 130. I added a M3 washer underneath the spring - heavens above, it all started being good again. A filament feeder I had printed was weak, structurally - the whole thing wobbled and strands could be pulled away by hand. Not to mention the wasted prints now sitting in the bin - around 0.5 KG of wasted filament trying to resolve this issue. Anyhow, I knocked a simple wooden spool holder, used my half baked end cones with ball bearings inserted and the crappy filament feeder to print another filament feeder. It worked. I have now printed the spool holder I wanted (own design). I'll be mounting this on top of the LHS Z axis fixture, using longer screws to utilise the existing 2 screw holes that also attach the z axis top plate.

In short. The supplied extrusion feeder is inadequate for the job. You can modify it a bit - file away some of the structure under the V wheel bearing (remove all first), delete the heatsink (it is totally superfluous), add some 9mm spacers (3mm ID, 5mm OD from Jaycar or equivalent), place a M3 washer underneath the spring and you're away again . BUT, for how long. The supplied spring is, apparently, inadequate for the job. It fails to retain its compressive force AND it can only extend this force to the limited movement of the lever system.

Thus the reason WHY I decided to buy the 'updated' feeder mechanism version - with tension adjusting screw. Mind you, the design is still 'seat of pants'. A screw mating with a screw and another screw 'holding' the lower part of the spring? I know I'll re-engineer this thing so it looks professional and works even better.

If anyone does actually read this, please do not hesitate to message me. If you want to add auto bed levelling, using the BLTouch, just ask. I've gone through the process. I can help. If you also have a GEEETECH 8mm acrylic I3, I have the mount. Took 4 design mods, but I got there.

Seems the missing message also did not upload the pics. I'll try again later.

[Napalm]

Thus the reason WHY I decided to buy the 'updated' feeder mechanism version - with tension adjusting screw. Mind you, the design is still 'seat of pants'. A screw mating with a screw and another screw 'holding' the lower part of the spring? I know I'll re-engineer this thing so it looks professional and works even better.

Hi, I have the same problems and can't get the extrusion feeder without an adjustment screw to work. I think they wrote that this is the newest and the best one?
What is the 'updated' feeder? The old model?

[ValiMDX]

Interesting Palad0n what you are saying.

Are you trying to print PLA or ABS? I have managed to get reasonably good quality on my PLA, but the ABS i've got ( from ice filaments) it managed to ruin a .3mm nozzle by clogging it, and it is underextruding for a .5mm nozzle. It seems that the ABS just gets out and curls, but if i feed it manually, it extrudes normally.. ALso i've tried tinkering with the feed rate and speed and sorts but no good result.

I will try with metal filament idle wheel to see if that is trully the problem.

[Trikky73]

This is exactly what is happening to my Prusa i3 that I just got a couple of weeks ago
It seems that the plastic that the feed assembly is made from and the spring are both week
Have ordered the aluminium feed assembly hopefully the spring in that is better
Has anyone found a good source for the spring in the feed assembly?

[NiklasO]

Had the same problem with my feeder. Added some washers to adjust the tension of the spring and now it works.
Also thinking about replacing the plastic parts with the older alu version.
Do I need the long or the short version? Thanks.