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Upgraded my UM2 with plus kit now under extrusion

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Posted · Upgraded my UM2 with plus kit now under extrusion

I think I have sorted my problem. I had tried cleaning the nozzle out a couple of times using atomic pulls with no luck. I usually only print in black material, be it carbon or PLA, so I didn't notice that the material hand't completely come out of the nozzle. I had some red to print for a change and that gave to the answer. After changing the filament I was still getting black material coming out of the nozzle for a good 5-10mins. So I spent around an hour purging the nozzle and doing atomic pulls until it finally came out clean. I then printed a test part with normal settings (i.e. same as the UM2) and its printed perfectly again. Normally atomic pulls clean the nozzle in 2-3 rotations, but it must have take about 20, if not more, to get this one sorted. Never had it that bad before.

BR

Rich

 

lucky you rich! yeah I have been using black a lot as well and I always do my atomic clean with an opposite colour as what I have been using and my white came out pure white. hopefully they can sort mine out asap!

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Posted · Upgraded my UM2 with plus kit now under extrusion

Lets hope so.

UM did find something broken in the feeder when it went back to them. So I guess it was a combination of a blocked nozzle and a broken part in the feeder!

Good luck!

BR

Rich

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Posted · Upgraded my UM2 with plus kit now under extrusion

just got mine back and sent me the parts to prove it worked. They changed out the feeder and said once they changed that it was working so yay for me!

Started printing a part great for the first hour then same issue.......changed to the new PLA that they sent me as well after doing a very good cleaning on the nozzle......still getting MAJOR under extrusion.........

they left their SD card in it so I tried printing the extrusion test and got the same thing (small dots connected by strings)

how did they get perfect prints and I'm getting fails? now this sounds like a user error but I'm using the same settings as they did and the same print.......nothing has changed

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Posted · Upgraded my UM2 with plus kit now under extrusion

You need to start over and throw all your assumptions out (e.g. "I know it's not the _____").

As far as underextrusion causes - there's just so damn many. none of the issues seem to cause more than 20% of problems so you need to know the top 5 issues to cover 75% of the possibilities and 1/4 people still won't have the right issue. Some of the top issues:

1) Print slower and hotter! Here are top recommended speeds for .2mm layers (twice as fast for .1mm layers) and .4mm nozzle:

20mm/sec at 200C

30mm/sec at 210C

40mm/sec at 225C

50mm/sec at 240C

The printer can do double these speeds but with huge difficulty and usually with a loss in part quality due to underextrusion. Different colors print best at quite different temperatures and due to imperfect temp sensors, some printers print 10C cool so use these values as an initial starting guideline and if you are still underextruding try raising the temp. But don't go over 240C with PLA.

2) Shell width confusion. Shell width must be a multiple of nozzle size. If nozzle size is .4mm and shell width is 1mm cura will make the printer do 2 passes with .5mm line width which is possible but requires you slow down much more to make a .5mm line out of a .4mm nozzle. If you really want this then set nozzle size to .5mm so it's clear what you are asking Cura to do for you.

3) Isolator - this is most common if you've printed extra hot (>240C) for a few hours or regular temps (220C) for 500 hours. It warps. It's the white part touching the heater block. Test it by removing it and passing filament though it by hand. Also if you notice parts of it are very soft then it's too old and needs replacing.

4) Curved filament at end of spool - if you are past half way on spool, try a fresh spool as a test.

5) curved angle feeding into feeder - put the filament on the floor -makes a MASSIVE difference.

6) Head too tight? Bizarrely MANY people loosen the 4 screws on the head by just a bit maybe 1/2 mm and suddenly they can print just fine! Has to do with pressure on the white teflon isolator.

5b) Bowden pushing too hard - for the same reason you don't want the bowden pushing too hard on the isolator.

5c) Spring pushing too hard. Although you want a gap you want as small as possible a gap between teflon isolator and steel isolator nut such that the spring is compressed as little as possible.

7) clogged nozzle - the number one problem of course - even if it seems clear. There can be build up on the inside of the nozzle that only burning with a flame can turn to ash and remove. Sometimes a grain of sand gets in there but that's more obvious (it just won't print). Atomic method (cold pull) helps but occasionally you need to remove the entire heater block/nozzle assembly and use flame. Or soak it in acetone overnight (after removing 90% of the material with cold pull).

8) Temp Sensor bad - even the good ones vary by +/- 5C and bad ones can be any amount off - they usually read high and a working sensor can fail high slowly over time. Meaning the sensor thinks you are at 220C but actually you are at 170C. At 170C the plastic is so viscous it can barely get out of the nozzle. You can verify your temp sensor using this simple video at youtube - on you tube search for this: mrZbX-SfftU

9) feeder spring issues - too tight, too loose

10) Other feeder issues, one of the nuts holding machine together often interferes with the feeder motor tilting it enough so that it still works but not very well. Other things that tilt the feeder motor, sleeve misaligned so it doesn't get a good grip. Gunk clogging the mechanism in there.

11) Filament diameter too big - 3mm is too much. 3mm filament is usually 2.85mm nominal or sometimes 2.9mm +/- .05. But some manufacturers (especially in china) make true 3.0mm filament with a tolerance of .1mm which is useless in an Ultimaker. It will print for a few meters and then clog so tight in the bowden you will have to remove the bowden from both ends to get the filament out. Throw that filament in the trash! It will save you weeks of pain

11b) Something wedged in with the filament. I was setting up 5 printers at once and ran filament change on all of them. One was slowly moving the filament through the tube and was almost to the head when I pushed the button and it sped up and ground the filament badly. I didn't think it was a problem and went ahead and printed something but there was a ground up spot followed by a flap of filament that got jammed in the bowden tube. Having the "plus" upgrade or using the IRobertI feeder helps you feel this with your hand by sliding the filament through the bowden a bit to see if it is stuck.

12) Hot weather. If air is above 30C or even possibly 25C, the air temperature combined with the extruder temperature can soften the filament inside the feeder such that it is getting squeezed flat as it passes through the feeder - this is obvious as you can see the problem in the bowden. The fix is to add a desk fan blowing on the back of the printer. Not an issue on the UM2 "plus" series.

13) Crimped bowden. At least one person had an issue where the bowden was crimped a bit too much at the feeder and although the printer worked fine when new it eventually got worse and had underextrusion on random layers. it's easy to pull the bowden out of the feeder end and examine it.

14) Small nozzle. Rumor has it some of the .4mm nozzles are closer to .35mm. Not sure if this is actually true. I'm a bit skeptical but try a .6mm nozzle maybe.

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Posted · Upgraded my UM2 with plus kit now under extrusion

You need to start over and throw all your assumptions out (e.g. "I know it's not the _____").

As far as underextrusion causes - there's just so damn many.  none of the issues seem to cause more than 20% of problems so you need to know the top 5 issues to cover 75% of the possibilities and 1/4 people still won't have the right issue.  Some of the top issues:

1) Print slower and hotter!  Here are top recommended speeds for .2mm layers (twice as fast for .1mm layers) and .4mm nozzle:

20mm/sec at 200C

30mm/sec at 210C

40mm/sec at 225C

50mm/sec at 240C

The printer can do double these speeds but with huge difficulty and usually with a loss in part quality due to underextrusion.  Different colors print best at quite different temperatures and due to imperfect temp sensors, some printers print 10C cool so use these values as an initial starting guideline and if you are still underextruding try raising the temp.  But don't go over 240C with PLA.

2) Shell width confusion.  Shell width must be a multiple of nozzle size.  If nozzle size is .4mm and shell width is 1mm cura will make the printer do 2 passes with .5mm line width which is possible but requires you slow down much more to make a .5mm line out of a .4mm nozzle.  If you really want this then set nozzle size to .5mm so it's clear what you are asking Cura to do for you.

3) Isolator - this is most common if you've printed extra hot (>240C) for a few hours or regular temps (220C) for 500 hours.  It warps.  It's the white part touching the heater block.  Test it by removing it and passing filament though it by hand.  Also if you notice parts of it are very soft then it's too old and needs replacing.

4) Curved filament at end of spool - if you are past half way on spool, try a fresh spool as a test.

5) curved angle feeding into feeder - put the filament on the floor -makes a MASSIVE difference.

6) Head too tight?  Bizarrely MANY people loosen the 4 screws on the head by just a bit maybe 1/2 mm and suddenly they can print just fine!  Has to do with pressure on the white teflon isolator.

5b) Bowden pushing too hard - for the same reason you don't want the bowden pushing too hard on the isolator.

5c) Spring pushing too hard.  Although you want a gap you want as small as possible a gap between teflon isolator and steel isolator nut such that the spring is compressed as little as possible.

7) clogged nozzle - the number one problem of course - even if it seems clear.  There can be build up on the inside of the nozzle that only burning with a flame can turn to ash and remove.  Sometimes a grain of sand gets in there but that's more obvious (it just won't print).  Atomic method (cold pull) helps but occasionally you need to remove the entire heater block/nozzle assembly and use flame.  Or soak it in acetone overnight (after removing 90% of the material with cold pull).

8) Temp Sensor bad - even the good ones vary by +/- 5C and bad ones can be any amount off - they usually read high and a working sensor can fail high slowly over time.  Meaning the sensor thinks you are at 220C but actually you are at 170C.  At 170C the plastic is so viscous it can barely get out of the nozzle.  You can verify your temp sensor using this simple video at youtube - on you tube search for this: mrZbX-SfftU

9) feeder spring issues - too tight, too loose

10) Other feeder issues, one of the nuts holding machine together often interferes with the feeder motor tilting it enough so that it still works but not very well.  Other things that tilt the feeder motor, sleeve misaligned so it doesn't get a good grip.  Gunk clogging the mechanism in there.

11) Filament diameter too big - 3mm is too much.  3mm filament is usually 2.85mm nominal or sometimes 2.9mm +/- .05.  But some manufacturers (especially in china) make true 3.0mm filament with a tolerance of .1mm which is useless in an Ultimaker.  It will print for a few meters and then clog so tight in the bowden you will have to remove the bowden from both ends to get the filament out.  Throw that filament in the trash!  It will save you weeks of pain

11b) Something wedged in with the filament.  I was setting up 5 printers at once and ran filament change on all of them.  One was slowly moving the filament through the tube and was almost to the head when I pushed the button and it sped up and ground the filament badly.  I didn't think it was a problem and went ahead and printed something but there was a ground up spot followed by a flap of filament that  got jammed in the bowden tube.  Having the "plus" upgrade or using the IRobertI feeder helps you feel this with your hand by sliding the filament through the bowden a bit to see if it is stuck.

12) Hot weather.  If air is above 30C or even possibly 25C, the air temperature combined with the extruder temperature can soften the filament inside the feeder such that it is getting squeezed flat as it passes through the feeder - this is obvious as you can see the problem in the bowden.  The fix is to add a desk fan blowing on the back of the printer.  Not an issue on the UM2 "plus" series.

13) Crimped bowden.  At least one person had an issue where the bowden was crimped a bit too much at the feeder and although the printer worked fine when new it eventually got worse and had underextrusion on random layers.  it's easy to pull the bowden out of the feeder end and examine it.

14) Small nozzle.  Rumor has it some of the .4mm nozzles are closer to .35mm.  Not sure if this is actually true.  I'm a bit skeptical but try a .6mm nozzle maybe.

 

Thanks for the ideas I've checked these already, I am very thorough when it comes to troubleshooting (its been my life for the past 14 years). I've been speaking with UM support for a while and they have been very helpful. We think there is a problem with the feeder design itself, I'm going to be swapping in my old feeder and if it works fine then the new design is the problem. If I still have a problem then its in the head unit. everything has been changed/swapped/adjusted/inspected/etc... that can be thought of.

My printer started doing this about 8hrs after upgrading, and when I got it back they printed parts for about 5-6 hours(beautiful!) and I did one hour and it started failing again. Seems a bit odd to me.

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Posted · Upgraded my UM2 with plus kit now under extrusion

well everyone I can say I have fixed the problem! with a lot of trial and error the problem is the actual feeder! I am actually printing parts for the first time in 3 weeks because I put my old feeder system back on! I will be contacting UM for a full refund.

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Posted · Upgraded my UM2 with plus kit now under extrusion

Thats very interesting, will have to see where UM go with this one. I was about to upgrade my UM2 with the kit, but I will hold fire for now. I have noticed that S3D makes a world of difference to print quality, far better IMHO that Cura.

BR

Rich

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