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ragged first layer and bad layer problem

Posted by RDEng 
ragged first layer and bad layer problem
September 04, 2014 07:56AM
Hello everyone!!

I finally setup my 3D printer. I have many problems but ı did not solve anything smiling smiley) . Please help me to find out the main problem on my printer.


there are 2 problems:

1. first layer doesn't look good but not for the adhesion. some areas didn't fill by the extruder. I 've tried many types of the level height, 0.1mm, 0.2mm, 0.3 mm. And also i 've tried a lot of degrees( 180 to 230). And extrusion width 50%, 100% and 200% tried.

All axes calibrated,tested and seems good.


2. as you can see the attached photo, some layer looks weak, i think filament does't flow nicely. I don't know what the problem is in my case, I'm trying and tring but does't solve problem.


My Printer setup:


PLA , 1.75

0.25 mm nozzle

heated bed @70C

0.2mm layer height

0.1mm z-axis height

Host: Repetier

Slicer: Slic3r

Arduino: Sprinter


And also my extruder motor really hot. Do you thing it causes?


Thank you guys!!

Edited 3 time(s). Last edit at 09/04/2014 08:22AM by RDEng.
Attachments:
open | download - IMG_1928.jpg (478 KB)
open | download - IMG_1931.jpg (528.5 KB)
Re: first layer and bad layer problem
September 04, 2014 08:28AM
If your extruder motor is really hot, it can cause these issues. Fix that first and see what problems remain.

A motor running hot usually means your stepper driver is turned a bit too high. You need to turn the trimpot on the driver board down. There are ways to calibrate the driver with meters, but I usually go by trial and error. Turn it too high and the motor gets hot; too low and it drops steps.
Re: ragged first layer and bad layer problem
September 04, 2014 02:10PM
Deaer jbernardis,

i tried but it was not work. Any idea ??


Custom 3D Printer,

Mechanical Engineer
Re: ragged first layer and bad layer problem
September 04, 2014 05:56PM
Problem 2 in the first picture could be that you are not extruding enough material. Does this problem occur all the way around the box?
Re: ragged first layer and bad layer problem
September 04, 2014 07:59PM
jtoombs,

yes, the problem occur around the box 1 or 2 layer. after that it's going normal good layer.

i've been triyng many things. But i realize most likely the problem occurs 2 main problems.

1. speed of extruder. if i print 50-60 mm/s , the problem occurs after 3-4 layer speed change.

2. flow rate. i agree with you, extruder does not extruding enough material or(!) filament does not flow as should be because of the real filament diameter, real diameter of nozzle or e-step settings. this things will solve but i guess i will solve the problem using extrusion multiplier.

it can be anything but i've been triyng and is running out of options.


what do you thing about 2 main problems and its solutions?

And please see the attached photos below. as you can see, some layer problem continues. :/

Thank you

Edited 1 time(s). Last edit at 09/04/2014 08:22PM by RDEng.


Custom 3D Printer,

Mechanical Engineer
Attachments:
open | download - IMG_1939.jpg (508.2 KB)
open | download - IMG_1940.jpg (442.8 KB)
Re: ragged first layer and bad layer problem
September 04, 2014 08:35PM
i saw the problem right now. while the problem occurs, i heared the some voice from extruder. extruder stutter and was not pull the filament . i push the filament slowly and problem disappeared instantly. somehow , extruder does not pull the filament as should be.


Custom 3D Printer,

Mechanical Engineer
Re: ragged first layer and bad layer problem
September 04, 2014 08:57PM
A .25mm nozzle is very small and it is going to be more finicky than a larger one. It could be your filament is not the best quality or it has moisture or even air bubbles inside. It could also be that your extruder is not "pushing" the filament as it should. This can be from a poorly designed hobbed bolt, to the hobbing being filled up to not strong enough pressure (spring) being put on the filament into the hobbed bolt.

This is what a good hobbed bolt should look like [airwolf3d.com]

This is a bad hobbed bolt [forums.reprap.org] I have also seen people use gears as hobbed bolts but that is a bad idea.

Also note that with a .25 nozzle you can't really go more than .20 layer height, .15 may even be better.
Re: ragged first layer and bad layer problem
September 04, 2014 09:08PM
Hi tmorris9,

i use the makerbot pla and stepstruder type extruder. But moisture... my filament waiting 3 months in my room @25C. it could be.

my latest print as you can see the photos(vase), layer height is .15. i agree with you .15 layer height ideal for .25 nozzle.


i do not understand, how the problem repeats? every 100-120 layer problem occurs and after 1-2 layer it disappear???

Edited 1 time(s). Last edit at 09/04/2014 09:08PM by RDEng.


Custom 3D Printer,

Mechanical Engineer
Re: ragged first layer and bad layer problem
September 04, 2014 09:11PM
Make sure that the spool of filament is mounted in some way so that the extrude only needs minimal pull to pull the filament into the hotend. This could be the reason it only happens periodically.

The extruder could be missing steps because it was for some reason hard to pull the filament and when missing steps you can usually hear some sort of noise from the motor.
Re: ragged first layer and bad layer problem
September 04, 2014 09:23PM
how can i fix the missing steps? i adjusted the pots, but i don't know how to understand fine tuning. anything else??

And also, if my extruder have missing steps, is it cause the poor layer problem? And is it repeat?


Custom 3D Printer,

Mechanical Engineer
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