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M2 nightmare with soft filiment

Posted: Mon Jun 18, 2018 9:04 pm
by airscapes
WTH EPA didn't work worth a damn, now bought some cleaning filament and my drive is all jacked up with the carp jammed in it.. Whats the trick, do I need to sell the M2 and buy something with newer technology to use the soft stuff? Probably had the tension too tight but this dive needs an updated so it doesn't crumple up the soft filament.
Any advice would be appreciated.. now I have to pull apart the dive to get this stuff out.. grrrrrrrrrrrrrrrrrrr
Gota say, the cleaning stuff is nice.. no side shooting since running that through, nice straight string when it purges before the print.
If only I could just run a couple hundred mm with out it jamming up after 50

Re: M2 nightmare with soft filiment

Posted: Tue Jun 19, 2018 12:29 pm
by willnewton
You may just need some tweaking. I have not printed with EPA, but try using Ninjaflex settings. I did see there is a flexible filament thread at the top of the filament subforum today that may help.

-Tension needs to be snug on the drive bearing for good grip.
-Retraction should be 0.
-Speeds at about 20mm/min. Start very slow. VERY SLOW. You may need to go down to 10mm/min and then go up 5mm/min until you get a birds nest, then back it down again.
-Slightly high extruder temp. (on the high side of manu. recommendations).
-No bed fan.

You HAVE to print slow because the extruder is trying to push a wet noodle through the nozzle. It has to have plenty of time to melt so it does not create back pressure, which leads to a bird nest in the extruder head.

Retraction will also cause issues because of the extruder pulling and shoving the filament too quickly.

I had a lot of issues with soft filaments initially, but have zero issues with them now on my M2. Just go slow and easy, there is nothing speedy about printing soft stuff.

Lastly, STOP trying to run 100mm test extrusions, which will cause you nothing but trouble. You are going have nothing but fails trying that! Seriously, you have to bump 1mm at a time. You may have good settings, but will never know it because you are choking the extruder trying run so much filament at a time. This may be a good way to check your flow on a stiff filament, but is not a good test for soft ones. Try a real world test print, like a 10*20*5mm block to get an idea if you have good settings, not the old “will it run OK if I press the 100mm EXTRUDE button test”, because as you have found out, it won’t. ;)

Re: M2 nightmare with soft filiment

Posted: Tue Jun 19, 2018 1:38 pm
by airscapes
My issue is the extruder drive design not the settings. I was running cleaning filament and following the manufactures instructions. This issue is the filament jams up in the drive. To much or too little tension and nothing to hold the filament in line if it starts to push out to the side. Then there is the issues of NO good way to know how tight you are other then measure the gap in the clamp or extract and look at the marks I will not even attempt to print EPA until I design a modified drive housing or get the guy who has done so already to share or sell the SLT (Dave where are you?).
I understand what you are saying about running the purge too fast and I will keep that in mind next time I clean the nozzle, but the stock set up of purge, wipe, then print also failed me when playing with EPA. Either stripped or jammed or slipping was the best I could get out of it.

Anyway, the cleaning filament that did run through worked well but unfortunately highlighted the shortcomings of the drive again.
Would be nice to be able to remove the pla, run a few inches of cleaner and go back to printing without changing the drive tension.. or at least having a way to get back to the proper tension quickly without extracting to look at the gear mark depth. I think with the proper u or v bearing and some adjustments to the drive housing this could work really well.. this is what I am talking about...

viewtopic.php?f=10&t=3210&p=23538&hilit=Drive#p23535

Image

Re: M2 nightmare with soft filiment

Posted: Tue Jun 19, 2018 2:33 pm
by sthone
I redesigned the stock drive to have a hinge and use springs for tension (see viewtopic.php?f=10&t=3283) and I never have to adjust tension when switching between any filaments anymore. I've never run EPA but I don't have any problems running flex stuff.... like mentioned you just have to run/feed slow and never hit the 100mm feed button when changing filaments.

When it comes to cleaning filament, yeah the stuff is great but it never feeds that well (It just doesn't have a consistent diameter) I just hit the 10mm button and put manual pressure on it to make sure it feeds enough then repeat.

Re: M2 nightmare with soft filiment

Posted: Tue Jun 19, 2018 3:04 pm
by jk42
For softer filaments (TPU,TPE) I suggest the following setup.

Suspend your filament above the printer and "gravity feed".
Use a .50 nozzle.
Print at about 600 mm/min.

Generally speaking, you should get great results as long as everything is in good working order.

Re: M2 nightmare with soft filiment

Posted: Tue Jun 19, 2018 3:36 pm
by airscapes
sthone wrote:
Tue Jun 19, 2018 2:33 pm
I redesigned the stock drive to have a hinge and use springs for tension (see viewtopic.php?f=10&t=3283) and I never have to adjust tension when switching between any filaments anymore. I've never run EPA but I don't have any problems running flex stuff.... like mentioned you just have to run/feed slow and never hit the 100mm feed button when changing filaments.

When it comes to cleaning filament, yeah the stuff is great but it never feeds that well (It just doesn't have a consistent diameter) I just hit the 10mm button and put manual pressure on it to make sure it feeds enough then repeat.
I just measured it a little while ago and yes, I see that it is all over the place and I did see your mod last night and was planning on checking my little box of springs. That is something can do with out much effort and it makes a lot of sense! I would love to try and mimic Dave design in the image above but have a lot of models to print and don't want to take the printer apart to measure and model. I did find a mode of the Rev E drive housing designed to add a touch sensor so maybe I should just print that and use that to do my one model.. still need to know the bearing ID and OD to try and make a sleeve or fine a U bearing that has a very shallow U to support 1.75mm filament.

Re: M2 nightmare with soft filiment

Posted: Tue Jun 19, 2018 3:42 pm
by airscapes
jk42 wrote:
Tue Jun 19, 2018 3:04 pm
For softer filaments (TPU,TPE) I suggest the following setup.

Suspend your filament above the printer and "gravity feed".
Use a .50 nozzle.
Print at about 600 mm/min.

Generally speaking, you should get great results as long as everything is in good working order.
Thanks Jason, I did figure out that the .5 nozzle was going to be needed for the soft stuff and was printing slow but not that slow..
The gravity feed sounds doable with the way my enclosure is built. I will need to fabricate a spool holder and give that a try.. maybe with the spring loaded tensioner gravity feed at 10mmS it would be fairly reliable.

Re: M2 nightmare with soft filiment

Posted: Wed Jun 20, 2018 1:10 am
by Gwhite
airscapes wrote:
Tue Jun 19, 2018 3:36 pm
I just measured it a little while ago and yes, I see that it is all over the place and I did see your mod last night and was planning on checking my little box of springs. That is something can do with out much effort and it makes a lot of sense! I would love to try and mimic Dave design in the image above but have a lot of models to print and don't want to take the printer apart to measure and model. I did find a mode of the Rev E drive housing designed to add a touch sensor so maybe I should just print that and use that to do my one model.. still need to know the bearing ID and OD to try and make a sleeve or fine a U bearing that has a very shallow U to support 1.75mm filament.
Check out viewtopic.php?f=7&t=6565&start=20#p36314

The stock bearing is 5mm bore, 5mm thick, and 16mm OD. McMaster Carr has a 14mm OD bearing (#7804K109). It should be possible to make a press on sleeve with a small groove to keep the filament from wandering sideways. That would allow using the stock extruder housing.

Re: M2 nightmare with soft filiment

Posted: Wed Jun 20, 2018 1:46 am
by airscapes
Gwhite wrote:
Wed Jun 20, 2018 1:10 am
airscapes wrote:
Tue Jun 19, 2018 3:36 pm
I just measured it a little while ago and yes, I see that it is all over the place and I did see your mod last night and was planning on checking my little box of springs. That is something can do with out much effort and it makes a lot of sense! I would love to try and mimic Dave design in the image above but have a lot of models to print and don't want to take the printer apart to measure and model. I did find a mode of the Rev E drive housing designed to add a touch sensor so maybe I should just print that and use that to do my one model.. still need to know the bearing ID and OD to try and make a sleeve or fine a U bearing that has a very shallow U to support 1.75mm filament.
Check out viewtopic.php?f=7&t=6565&start=20#p36314

The stock bearing is 5mm bore, 5mm thick, and 16mm OD. McMaster Carr has a 14mm OD bearing (#7804K109). It should be possible to make a press on sleeve with a small groove to keep the filament from wandering sideways. That would allow using the stock extruder housing.
Do you think a 1mm thick printed sleeve would be thick enough? seems too thin to press fit tight enough.

Re: M2 nightmare with soft filiment

Posted: Wed Jun 20, 2018 11:17 am
by Gwhite
It doesn't have to be a super tight fit, and you could even use bearing retainer adhesive on it. Also, it's only going to be ~ 1 mm thick at the bottom of the groove. The rest of it will be at least a half a mm thicker.

I've got one of the bearings, I just haven't had time to make the grooved sleeve. I''ll need to grind a small form tool to cut the groove. I think I will use aluminum so that if it ever get cranked into the drive gear, it won't dull the gear too badly.