I have printed some smaller pieces already (up to 40 x 40 mm^2 Area)
so I decided to go for bigger parts. I started printing a cover for the board a few times,
but every time the printer seems to start to mess at some point in the first layer, which
makes the whole layer from there on become a real mess
Here’s a picture(was printed from left to right): dropbox.com/sc/lf4z78nq58vg … 4v_1XqZpda
It seems that for the small prints the printer never reached the point in any area,
where it would start to mess, so that those went good, while this bigger part sucks.
At first I thought there’s some filament that was stuck to the extruder and dropped off at some point,
but after looking after this I didnt really see any point where this could have happened.
First layer height is 0.3 mm, first layer speed is 50%, all the other parameters are as they were.
if the problem is for big objects only, it probably means that the heat bed is not well leveled ??
is i see an bow is defind by R*alpha , for the same angle of the bed lvl if the piece is bigger (R bigger) the bow is bigger !
( i dont know , I just think logically )
dont know if it could help but try to lvl the heat bed and the calibrate the Z end stop correctly.
Well, I am using a glass plate as a plane surface, I got it leveled as good as possible and also my z end stop is ok, I think.
Wouldn’t it mess all over the place otherwise?
idk it looks like there’s a kind of seeding point for the mess, from where on it starts to spread.
The part in the front is still printed smooth and good.
Tomorrow I’m gonna try stuff like choosing a smaller extrusion rate and going even slower for the first layer, maybe this helps
I get the same problem with my printer. I have found that as long as the extruder doesn’t catch on the uneven parts the 2nd layer will flatten it out and the rest of the print will be fine. (only had my printer working for 1 day and have learned a lot in that short time) It also helps if you spray the heat bed with hair spray to keep the part stuck to the plate and prevent larger parts from warping - it does however make taking the parts off the plate a bit harder too but it is well worth it.
That’s a nozzle height issue. It’s a difficult balancing act between squishing the filament into the bed to get it to stick and the nozzle tearing up previously laid filament. The extrusion width for the first layer comes into it too.
Often the subsequent layers will smooth those defects out.
I had to reduce my extruder steps down to 510, meaning I was extruding way too much before.
I don’t know why it was that much miscalibrated, I didn’t touch any of the other settings,
but at least it seems to work for now
[quote]It looks like my problem shown below
viewtopic.php?f=51&t=12743
some filament are more sensitive and it also happened with the first layer sometimes.
I have solved this problem by increasing the extruder multiplier somewhat (from 1 to 1.2) .[/quote]
no this isnt the same, your also having it on the second and third layer,
[quote]It seems like I solved my problem now
I printed the cube stack test from hunters guide: reprap.org/wiki/Triffid_Hunter%2 … de#E_steps
I had to reduce my extruder steps down to 510, meaning I was extruding way too much before.
I don’t know why it was that much miscalibrated, I didn’t touch any of the other settings,
but at least it seems to work for now[/quote]
strange as most poeple and my self have increase the E-step to 680 default = 600 (680 is just out of my head its not correct.)
and why 680 thats the calibration for the E-step if you extrude 100mm of fillement it also needs to be 100mm.
if you like to decrease or increase the E-step you should change the “extrusion multiplier” on slicer.
as default velleman uses 1.07 because the E-step is on 600.
and if you calibrate everything correct so e-step somewhere to 680 and extrustion muliplier on 1 you can use the ADVANCED tab op slicer to change the amount of fillement that will be extruded on differnt segments of printing “first layer, perimeters, infill, enz”
and i also have the same issue, and i use a Fingerdial to level the bed so its 0.05mm correct. but i noticed it allways happin on the same spots.
but if the second layer goes o’k, i’m happy.
I have also noticed a problem in the past with the first layer, when you are printing over the sensor. As can be shown here http://www.mijnalbum.nl/Album=VGIMT3Q4#NGYANCXK the temperarure at the location of the sensor is increased thanks to the high temperature of the filament. As a result the print bed is not heated as long as the nozzle passes close to the sensor. Other part are cooling down resulting in bad prints if the adjustment is not optimal.
This can be the reason why bad prints are obtained with large prints, only.
I calbrated my e-steps and now this whole thing starts to look better.
Still I have my PLA detaching from the bed at some points and no idea why.
Never had a problem like this at small prints, and here it only happens at some points.
I think this combined with too much filament being extruded was the reason for my problem
in the first place.
At the second layer the whole thing is being homogenized and at the third layer I dont even see these defects anymore.
However, looking at the bottom after the print is finished, you can still see where the PLA did not stick too well.
I’m printing with extrude 190° and bed 55°, and my bed is as clean as I can get it, I am using a glass plate hereon top of the heat bed.
Here’s a picture. As I said, it only happens at some points, and then seems to spread a bit, but most of the layer seems to be printed nice. dropbox.com/s/mjvg5hd6bfaqt … 5.jpg?dl=0
