Prusa i3 intermittent extrusion

Hi, first of all sorry for my bad english, I have a Prusa i3 Pro B, It had worked well so far and now it's getting problems. I tried to calibrate the bed and still the same.
There is a picture:

Not close enough to the bed, keep calibrating. Get a filler gauge and without filament print something, stop the print as soon as it draws the first few lines and measure the distance between bed and nozzle, it should equal your layer height.

I tried and nothing... Any ideas?

If Z offset is correct, next step is to check extruder gear and idler bearing. Be sure the gear is secure against stepper shaft and that the idler press firmly against the filament, once that's checked measure the stepper driver voltage (ground + trim pot) to be sure it matches the requirements of the stepper motor (ball park figure 0.4 ~ 0.6)

Use a feeler gauge [www.amazon.com] to set the height of your print nozzle rather than a sheet of paper. Remove the 0.10 mm gauge from the set before using it. You can get one of these from most automotive parts stores.

Check your head. Is it loose? If it is moving in directions it is not supposed to, tighten or replace parts that cause unwanted movement.

Check your Y-axis. Is it loose? Can your platform be moved in directions it is not meant to or does it move freely down the y-axis. If your y-axis is loose or your platform wiggles, tighten screws as necessary. If your platform does not slide down the y-axis freely or moves in directions it is not supposed to, replace the bearings.

What is your frame made of, wood, plastic or metal? Is there any contortion of the frame (even 0.10mm)? If so you may want to tighten the screws on the frame or upgrade to an all-metal frame such as a P3Steel.

Who makes your printer? Can you send a picture and a manufacturer's link?


By The Way, Your English is better than I can speak your native language.

First of all thank you for answer, there is the link: [www.geeetech.com]

The first day I had this trouble too but the second day It disapear and I don't know exactly why... I have been two months with the 3D printer working perfectly and is compact, nothing loose.

Quote
Lymphomaniac1
Use a feeler gauge [www.amazon.com] to set the height of your print nozzle rather than a sheet of paper. Remove the 0.10 mm gauge from the set before using it. You can get one of these from most automotive parts stores.

Check your head. Is it loose? If it is moving in directions it is not supposed to, tighten or replace parts that cause unwanted movement.

Check your Y-axis. Is it loose? Can your platform be moved in directions it is not meant to or does it move freely down the y-axis. If your y-axis is loose or your platform wiggles, tighten screws as necessary. If your platform does not slide down the y-axis freely or moves in directions it is not supposed to, replace the bearings.

What is your frame made of, wood, plastic or metal? Is there any contortion of the frame (even 0.10mm)? If so you may want to tighten the screws on the frame or upgrade to an all-metal frame such as a P3Steel.

Who makes your printer? Can you send a picture and a manufacturer's link?


By The Way, Your English is better than I can speak your native language.

Now that I saw the printer, I suspect it is your hotend PTFE liner the one causing the problems.

Lift your Z axis all the way up, heat up your hotend and remove the filament and nozzle, once removed let it cool down and take a look at the white tube inside the stainless steel pipe, if deformed, burnt signs or melted filament in the threaded section of the heat block, replace it with a new one.

Quote
ggherbaz
Now that I saw the printer, I suspect it is your hotend PTFE liner the one causing the problems.

Lift your Z axis all the way up, heat up your hotend and remove the filament and nozzle, once removed let it cool down and take a look at the white tube inside the stainless steel pipe, if deformed, burnt signs or melted filament in the threaded section of the heat block, replace it with a new one.

I did that, clean the nozzle and the steel pipe, inside there isn't white tube, it's all made of metal. I cleaned and still having the same trouble...

Ok, lets move to the next steps:

What material are you using, what temperatures and what speed?

Are you using an old filament, a new one, did you switched supplier?

The problem began while using the same material or as you switched to a different material/supplier?

Have you test different speeds and temperatures and have the same result?

Have you slice the part again or with another slicer software?

Have you test swapping stepper drivers or motors?

Did you changed or updated firmware before the problem started?

One more question, do the results are the same if you print in a different place of the build plate?

Edited 1 time(s). Last edit at 12/03/2016 12:55PM by ggherbaz.

Quote
ggherbaz
Ok, lets move to the next steps:

What material are you using, what temperatures and what speed?

Are you using an old filament, a new one, did you switched supplier?

The problem began while using the same material or as you switched to a different material/supplier?

Have you test different speeds and temperatures and have the same result?

Have you slice the part again or with another slicer software?

Have you test swapping stepper drivers or motors?

Did you changed or updated firmware before the problem started?

One more question, do the results are the same if you print in a different place of the build plate?

First of all, I used exactly the same a week ago and it's worked perfectly. I answe your questions in order:

- PLA, 200º, and speed 25-40...

- New filament, I have object good printed with this filament, is the usual.

- Exactly the same material, and the same all.

- I tried differents temperatures but not speeds, I'll try.

- I'll try with Cura, and I tried with other pieces and still the same trouble.

- That's my next move, swap the step motors

- No chages since it worked well.

- Yes, still the same.

Thank you, I wait your answer.

Ok, need some more info:

Nozzle size
Layer height
Extrusion width
Extrusion multiplier

While printing, does the extruder clicks, misses steps, or chew up the filament?

Are you printing from computer or SD card? Have you tried both with same results?

While printing your hotend temperature fluctuates a lot or is quite stable?

Are you using auto bed leveling?

Quote
ggherbaz
Ok, need some more info:

Nozzle size
Layer height
Extrusion width
Extrusion multiplier

While printing, does the extruder clicks, misses steps, or chew up the filament?

Are you printing from computer or SD card? Have you tried both with same results?

While printing your hotend temperature fluctuates a lot or is quite stable?

Are you using auto bed leveling?

Nozzle 0.4
Layer 0.4 (I used to use 0.2 or 0.4)
Extrusion width? filament? It's 1.75 mm. I don't know what you want to say.
Extrusion multiplier 1

I know the trouble when the extruder clicks, that It doesn't grab the filament, but isn't that, no sound heard.

The hotend temperature is really stable.

And I haven't autobed leveling, Can I buy and put in the printer?

The extrusion width is a setting in the slicer used to specify the width of the extruded filament, it can be set manually or automatically, for a 0.4 nozzle the auto mode will set it at 0.48, in manual you can set it to any value that the nozzle can effectively extrude although it is recommended to set it higher than the nozzle size.

For a nozzle size of 0.4 the maximum layer height should not exceed 0.3, anything above that will translate in layer adhesion problems and definitely will create the artifacts shown in your photo.

Other issue might be the filament size, have you measured the filament in several places and set the average diameter in the slicer or you are just setting it at 1.75? If your real filament size is like 1.72 but you are setting it at 1.75 you will be under extruding and will have the same effects on the print shown in the photo.

My advice is to reprint with the following settings:

Nozzle size 0.4
Extrusion width (auto or 0.48)
Extrusion multiplier 1
Layer height 0.2~0.3 max.
First layer speed 50%
Put in the slicer the real diameter of the filament.

I don't know what you are using for bed adhesion, but if you can purchase Elmer's purple glue stick do it and apply a thin coating while bed is at temperature.

Yes you can buy all the things needed for auto bed leveling and set it in your printer, but I asked because if you have it set and your Z offset was wrong it will create those artifacts.

Quote
ggherbaz
The extrusion width is a setting in the slicer used to specify the width of the extruded filament, it can be set manually or automatically, for a 0.4 nozzle the auto mode will set it at 0.48, in manual you can set it to any value that the nozzle can effectively extrude although it is recommended to set it higher than the nozzle size.

For a nozzle size of 0.4 the maximum layer height should not exceed 0.3, anything above that will translate in layer adhesion problems and definitely will create the artifacts shown in your photo.

Other issue might be the filament size, have you measured the filament in several places and set the average diameter in the slicer or you are just setting it at 1.75? If your real filament size is like 1.72 but you are setting it at 1.75 you will be under extruding and will have the same effects on the print shown in the photo.

My advice is to reprint with the following settings:

Nozzle size 0.4
Extrusion width (auto or 0.48)
Extrusion multiplier 1
Layer height 0.2~0.3 max.
First layer speed 50%
Put in the slicer the real diameter of the filament.

I don't know what you are using for bed adhesion, but if you can purchase Elmer's purple glue stick do it and apply a thin coating while bed is at temperature.

I did it, the first layer its ok, but the next not, was the speed then. But allways I have to print 50% speed? No way to fix it?

Not perfect, some narrow line...

It may be that the plastic is not sticking to your bed. Have you tried blue painter's tape on you bed, glue stick or both?

The only layer you need to print really slowly is the first one, that's why usually the slicer have a setting specifically for first layer speed. If too fast the print will not adhere well to the bed and filament will come out really thin.

Ok now since it looks like it's getting a little better but still need some tweak, the next step is getting more material extruded since it looks like it might be under extruding.

For next print increase the multiplier to 1.2~1.4 and check for improvements if that's the case then you will have to adjust either the steps per mm or the feedrate in the firmware.

Do you have plastic X-axis parts. Geeetech makes metal ones to replace the plastic ones making your carrier and axis ends much sturdier. See:
[www.ebay.com]-

They also make an aluminum frame upgrade for your printer, but since it does not have side supports on the XZ frame like the P3Steel has and side supports for the Z Motor Fixed Plate I do not know haw sturdy this kit really is. See:

[www.ebay.com]

Edited 1 time(s). Last edit at 12/05/2016 01:01PM by Lymphomaniac1.

Pele:

Can you send pictures of your models after you make adjustments?

I have also purchased a prusa i3 pro b kit from Geeetech and my prints started to look EXACTLY as yours.
I was "shocked" when I saw this post and the picture because it looked to be nearly an exact copy of a picture I caputred.

So, what to do?

I Googled and there was always answers like "level your bed", check the height of the nozzle ot the bed.
But I had already been printing several good models and was sure it was not the issue.

I adjusted the Z-home up and down with no result to the better.
Then I tried to raise the temp of the extreuder and got a better result but not good.
So I tried to raise the temp once again, and the result was nearly perfect.

But the temp now was 250 C for PLA....
I even saw a brownish burnt blob on the nozzle.

Back to 220 C. The problem was there again...

I had printed several good models so start tweaking the setting in the slicer or config.h seemed a bad idea.

So I started to suspect the extruder. Was it slipping?
Higher temp, softer plastics, eyazier for the motor to feed the filament.
I demounted the fan and the cooler block and inspected the feed mechanism.
I pulled and pushed the filament and observed the stepper. Sometimes it followed my pushe and pull, sometimes it did not.

The spring not strong enough?
I took a couple of pliers and forced the spring to be ca 10 mm longer.
Tested again to pull and push the filamen.
Now the motor never slipped.

Put all together again and did a test print of the slice.
Voila! Perfect result.
You can push a lever down when inserting filamnt wich compresses the spring.
Maybe I had pushed this lever to hard and deformed a spring who almost ceratin is of really bad quality.

I hope this helps.

Cheers from Sweden.

Edited 1 time(s). Last edit at 12/09/2016 05:22AM by mattssen.

Quote
mattssen
I have also purchased a prusa i3 pro b kit from Geeetech and my prints started to look EXACTLY as yours.
I was "shocked" when I saw this post and the picture because it looked to be nearly an exact copy of a picture I caputred.

So, what to do?

I Googled and there was always answers like "level your bed", check the height of the nozzle ot the bed.
But I had already been printing several good models and was sure it was not the issue.

I adjusted the Z-home up and down with no result to the better.
Then I tried to raise the temp of the extreuder and got a better result but not good.
So I tried to raise the temp once again, and the result was nearly perfect.

But the temp now was 250 C for PLA....
I even saw a brownish burnt blob on the nozzle.

Back to 220 C. The problem was there again...

I had printed several good models so start tweaking the setting in the slicer or config.h seemed a bad idea.

So I started to suspect the extruder. Was it slipping?
Higher temp, softer plastics, eyazier for the motor to feed the filament.
I demounted the fan and the cooler block and inspected the feed mechanism.
I pulled and pushed the filament and observed the stepper. Sometimes it followed my pushe and pull, sometimes it did not.

The spring not strong enough?
I took a couple of pliers and forced the spring to be ca 10 mm longer.
Tested again to pull and push the filamen.
Now the motor never slipped.

Put all together again and did a test print of the slice.
Voila! Perfect result.
You can push a lever down when inserting filamnt wich compresses the spring.
Maybe I had pushed this lever to hard and deformed a spring who almost ceratin is of really bad quality.

I hope this helps.

Cheers from Sweden.

I hope it's that!!

Tomorrow I'll try, thank you very much.