skipping extruder!

hello! I'm having some problems with my extruder motor i think! first i thought it was a clogged nozzle, cleaned it out, started printing again, worked fine for the first layers... then the skipping began again! so i heated it up att about 220 Celcius and carefully manually "extruded" some filament, worked fine... back to printing, skipping after a layer or too! how can i get rid of this problem..? weirdest part is that i printed a new thumbwheel for the fisher with no problems at all, but as soon as i try to print a little bit larger prints, or even other smaller prints, it skipps! maybe a coincidence but... i have tried printing slower, faster, hotter, colder, all those things, tried with and without retraction, always same result! help would be really nice right now, my first printer so I'm out of ideas! thanks! =)

Edited 1 time(s). Last edit at 09/01/2015 01:33PM by kellef.

Hi, probably a incorrectly defined filament size.

Check again at 5 places (along 50cm for example), drop the 2 extremes numbers and set the remaining average into the software.
There can be much differences between spools even in one spool (depending on the quality)

Quote
Greg_be
Hi, probably a incorrectly defined filament size.

Check again at 5 places (along 50cm for example), drop the 2 extremes numbers and set the remaining average into the software.
There can be much differences between spools even in one spool (depending on the quality)

oh okay! will definitely try that as soon as i get home! but it doesn't explain why the thumbwheel print went perfect, twice! I'm trying to print myself a new frame for my quadcopter, and it always goes wrong on this piece! although, the thumbwheel was the only one for a while that didn't skipped i guess! still running the same roll of eSun filament I've had since day one... but totally noted will check as soon as i can! so i can i just enter the new filament size in slicer or do i have to tighten the screw to make the bearing push down harder on the filament?cause i tried that to... hope you understand what i mean, I'm from sweden so, english isn't my main language! so much to learn as a newbie xD thanks for the quick response! crossing fingers! =)

Clean the hobbed insert.

Calibrate the steps/mm on the extruder.

Reduce the retraction speed.

Quote
Theolodian
Clean the hobbed insert.

Calibrate the steps/mm on the extruder.

Reduce the retraction speed.

this sounds like a good idea! i did clean out the nozzle and the hobbed insert today but i have never calibrated the extruder motor! I thought about it before the printer was assembled, but i worked in the beginning with no problems so i kind of forgot about it, thanks for the answer! better do some googling! =)

Don't worry for the english, it's not my mother tongue too. And we are talking from newbie to newbie (Started 3D printing in june, and Fisher in july), so don't hesitate to ask ! I'll try to be a little bit more detailed in my explanations.

The wrong filament size causes the software to tell the extruder to push too much (or too few) filament into the nozzle and then the extruder slips.

The tightening screw is correctly tighten when you can't remove filament pulling it by hand while stopping wheel movement (with the other hand ;-) ).

Another thing you can do is cleaning your extruder's teeth (pulley), because when the filament slip, it is dirty really really quickly !

Like you tried, the temperature has an impact on the extrusion speed, if you calibrate correctly you filament, the tigthening screw and the software, the Fisher is really reliable.

I learned a little secret of retraction. This applies to all types of extruder.

The extruder requires enough tension to push filament between hobbed gear and bearing.
If it's not strong enough to overcome the pressure during heavy retraction, layer skipping would occur, eventually failed printing.
Small models suffer the most.

Failed print


No retraction


After the adjustment of lever tension on the extruder


Edited 2 time(s). Last edit at 09/01/2015 04:53PM by janpenguin.

Oh i think i might have found the issue! Not sure yet though, haven't been home yet to try! I used to run it through pronterface on my MacBook, but recently switched to and older pc I had laying around... Never had problems when I ran It with the MacBook! Gonna try when I come home to see the difference! If it works i guess it's the settings in arduino on my pc?

Your fisher should have a duet, dropkick Pronterface and do everything via the web interface,this way the duet is doing all the heavy lifting and your PC/Macbook is just a display interface

---

RepRapPro Mendel 3 Tricolour
RepRapPro Fisher
-Carbon Arms
-Easy adjust Carriage+effector
-axis stiffness mods
HE3D -600 delta
-Duet 0.8.5
-PanelDue
-DC42 Height probe
-RobotDigg metal components
Simplyfy3D
RS Design Spark CAD

Quote
bgkdavis
Your fisher should have a duet, dropkick Pronterface and do everything via the web interface,this way the duet is doing all the heavy lifting and your PC/Macbook is just a display interface

It sure does have a duet! But I had some serious issues with my router since it's a really bad one, and I can't get it to work with the fisher unfortunately =/

Direct connect it to your laptop using a regular network cable, make sure you set your config.g to fixed IP settings and laptops Ethernet settings to the same subnet.

---

RepRapPro Mendel 3 Tricolour
RepRapPro Fisher
-Carbon Arms
-Easy adjust Carriage+effector
-axis stiffness mods
HE3D -600 delta
-Duet 0.8.5
-PanelDue
-DC42 Height probe
-RobotDigg metal components
Simplyfy3D
RS Design Spark CAD

Quote
bgkdavis
Direct connect it to your laptop using a regular network cable, make sure you set your config.g to fixed IP settings and laptops Ethernet settings to the same subnet.

okay! will look in to this too! i remember i tried this thing in the beginning with the fisher but, just couldnt get it to work! bet theres a good guide somewhere just waiting for me to read it now though! is the difference that big really? =) i kinda like pronterface so far! tried repetier to but, didnt like it as much!

its fairly easy, in your config.g set the IP to 192.168.1.14, and a subnet mask of 255.255.255.0, the lines to change are marked in the config.g

Then go to yur computers network settings and set you Iinternet protocol version 4 settings for your LAN port to fixed IP with an IP address of 192.168.1.100 and a subnet mask of 255.255.255.0.

finally open your web browser, google chrome is best, and enter 192.168.1.14 in the URL and it should load.

if you have problems and your using wifi turn your wifi off temporarily and try again

---

RepRapPro Mendel 3 Tricolour
RepRapPro Fisher
-Carbon Arms
-Easy adjust Carriage+effector
-axis stiffness mods
HE3D -600 delta
-Duet 0.8.5
-PanelDue
-DC42 Height probe
-RobotDigg metal components
Simplyfy3D
RS Design Spark CAD

Quote
bgkdavis
its fairly easy, in your config.g set the IP to 192.168.1.14, and a subnet mask of 255.255.255.0, the lines to change are marked in the config.g

Then go to yur computers network settings and set you Iinternet protocol version 4 settings for your LAN port to fixed IP with an IP address of 192.168.1.100 and a subnet mask of 255.255.255.0.

finally open your web browser, google chrome is best, and enter 192.168.1.14 in the URL and it should load.

if you have problems and your using wifi turn your wifi off temporarily and try again

ill try this right away! doesnt matter if the wifi is on or off, this pc is only for 3D printing, i do my slicing on the mac, and download everything there, so ill just keep it off i guess! ill get back to you as soon as i tried! awsome, thanks for the help! like i said earlier, so much to learn as a newbie! truly starting to understand the value of this forum! =)

Like you I have had a few bad days grappling with the extruder feed! But the advice from Greg is the real clue:" The tightening screw is correctly tighten when you can't remove filament pulling it by hand while stopping wheel movement (with the other hand ;-) )."

I went back and reviewed the build instructions of commissioning.. I took motor out and played with the tension screw.
Mine was way over tightened! It seem that you need very little tension. Set it with a piece of filament. Reassembled and Magic it works really well. Probably only a half turn needed - where before I had 2 1/2 turns !

So in my case over tensioning the roller! I also remeasured filament and changed slicers size. and Dropped temp back to my normal setting (ran hot to get out of trouble - so I thought.)

Trust this works for you ?

Also new Fisher owner and first time 3D printing

Edited 1 time(s). Last edit at 09/02/2015 09:42AM by rogerdiver.

so i just calibrated the extruder drive! printing first print now, no skipping so far, although this is a small print, gonna have to try some bigger stuff after this! i changed from 144 steps per mm to 137, which was about 5 mm of raw filament... could it really make that big of a difference? crossing fingers now! i have an old print of the thing im printing now for comparision! still printing from pronterface btw!

This change is also integrated (but not described) in the last Fisher SD image 020915

Quote
Greg_be
This change is also integrated (but not described) in the last Fisher SD image 020915

hmm, you sure? checked the config.g file for e steps, still 144 in the new update..? im gonna try it out now anywas, if its better ill stick to it, if not, back to my 137 steps! mayby im missunderstanding what this is? =)

Edited 1 time(s). Last edit at 09/03/2015 01:42PM by kellef.

This is the config.g in the zip I downloaded yesterday

Quote
Greg_be
This is the config.g in the zip I downloaded yesterday

[attachment 61393 Capturedcran2015-09-0319.47.25.png]

oh, thats wierd! i must have clicked the wrong download or something..? im 100% sure that the new i just downloaded was at 144! haha, my bad! well, about to test my second print at 137 now, first one didnt skip at all, so thats good i guess! =)
EDIT: STILL skipping, when i tried the second print... im really out of ideas now... ive calibrated the extruder, measeured the filament over 300 mm to see size difference to change it in slicer, ive cleaned the hubbed insert, tried to tighten it, tried it looser... there must be something more im missing?? getting kinda tired of this -.-

Edited 1 time(s). Last edit at 09/03/2015 02:06PM by kellef.

Did you reduce the retraction speed?

Quote
Theolodian
Did you reduce the retraction speed?

i did not! is this also in the config.g file or is this in slic3r? but retraction speed should only effect the pullback of the filament, not the feeding, or am i wrong here? because the retraction is not the problem, it skipps mid printing! maybe im missunderstanding that term also?

In slic3r. It pulls back a few mm and slams it back forward with the same speed setting. More prevalent when moving across open spaces but also does it every layer. Mine had issues at 3,000mm/min - dropped to 2500 and much happier even though I increased the retraction distance a bit. You end up with a bulb at the end of the filament between the end of the bowden tube and where the nozzle necks down, this seems to catch if retraction is too aggressive. Pull the filament out and you will see what I mean.

Quote
Theolodian
In slic3r. It pulls back a few mm and slams it back forward with the same speed setting. More prevalent when moving across open spaces but also does it every layer. Mine had issues at 3,000mm/min - dropped to 2500 and much happier even though I increased the retraction distance a bit. You end up with a bulb at the end of the filament between the end of the bowden tube and where the nozzle necks down, this seems to catch if retraction is too aggressive. Pull the filament out and you will see what I mean.

Oh yeah I've seen this a couple of times, I reduced the distance of retraction, didn't really help, so this is next on my to do list! Awesome, thanks for the advise!
Still, really weird that I can print the thumbwheel nicely every time, same settings as basically all other prints fail with!

Quote
Theolodian
In slic3r. It pulls back a few mm and slams it back forward with the same speed setting. More prevalent when moving across open spaces but also does it every layer. Mine had issues at 3,000mm/min - dropped to 2500 and much happier even though I increased the retraction distance a bit. You end up with a bulb at the end of the filament between the end of the bowden tube and where the nozzle necks down, this seems to catch if retraction is too aggressive. Pull the filament out and you will see what I mean.

I also reduced retraction speed to 2400 in Slic3r.
The fast backward / forward movement tends to grip the filament a little too much and make a "hole" that the extruder gear will be stuck in

My retraction distance is 3.2mm

I too can't seem to print large objects. I am unconvinced it has anything to do with retracting setings or how hard your idler wheel pushes against the filament. It is a reproducable event that happens after ~30-60 minutes of printing. In the old days with another printer, this was caused by a gap between the bowden cable and the hotend parts. PLA would creep up into that gap, solidify and jam the filament.
I have tried to do a 'cold pull' to get an impression of the filament path in the hotend and how it looks in case of a blockage, but have not found any obvious faults yet.
I do not really like the step pattern in the nozzle (2mm drill-> 1mm -> 0.5mm) but I doubt that is not the cause of the blockage.

So it seems that a blockage can occur with this hotend,
Here are some things that I think that are NOT the cause:
idler wheel in drive too tight (Does not explain sudden blockage, pushing filament does not help)
Uncalibrated extruder (too small a deviation to matter, does not explain sudden blockage)
Too much/hard retraction (does not explain sudden blockage).

Who else has some testable hypotheses what could be causing these blockages?

Are you sure it caused by a blockage? The extruder motor on the Fisher is run at quite a high current (1.2A) and the Duet is mounted horizontally, which is not ideal for cooling. If the ambient temperature is high, could the stepper driver be overheating and going into thermal shutdown? You could use a small fan to blow air across the Duet along the line of the stepper drivers - that is what I do on my Kossel. However, I am not aware of anyone else reporting this type of problem on the Fisher.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

One thing I dont like on the fisher is the extruder has a very low steps per mm ratio caused by the hobbed insert being direct driven by the motor, this will increase motor load, I much prefer the gear driven extruder on my mendel.

---

RepRapPro Mendel 3 Tricolour
RepRapPro Fisher
-Carbon Arms
-Easy adjust Carriage+effector
-axis stiffness mods
HE3D -600 delta
-Duet 0.8.5
-PanelDue
-DC42 Height probe
-RobotDigg metal components
Simplyfy3D
RS Design Spark CAD

Quote
bgkdavis
One thing I dont like on the fisher is the extruder has a very low steps per mm ratio caused by the hobbed insert being direct driven by the motor, this will increase motor load, I much prefer the gear driven extruder on my mendel.

I prefer 3:1 geared extruders too. Direct drive extruders work best with long high-torque motors (which the Fischer doesn't have) driven at 80 to 90% of their rated current (which the Fischer does). I guess you could substitute a longer motor, if the extra weight wouldn't cause a problem. Something like JKHS60-1206 which is £16 on eBay UK.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42
Are you sure it caused by a blockage? The extruder motor on the Fisher is run at quite a high current (1.2A) and the Duet is mounted horizontally, which is not ideal for cooling. If the ambient temperature is high, could the stepper driver be overheating and going into thermal shutdown? You could use a small fan to blow air across the Duet along the line of the stepper drivers - that is what I do on my Kossel. However, I am not aware of anyone else reporting this type of problem on the Fisher.

im pretty sure its not blocked! i dissasembled the hotend, cleaned it out, and heated up the nozzle, put a 0.17 guitar string trough it... it was clean as a whistle! but still skipping! its reeeally starting to upset me, because when i extrude in pronterface, there is nooo problem at all... i can put 100 mm, press extrude, and its no problems... and its not hard to push through manually... its just when i print! and its not every print although i use the same settings. and the printer can do this after only one minute of printing, so its not overheated, im sure of that! =/

Edited 2 time(s). Last edit at 09/04/2015 11:02AM by kellef.