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Prusa i3 bad bottom and top layers

Posted by sidhabo 
Prusa i3 bad bottom and top layers
May 25, 2014 02:25PM
Trying to get some decent quality out of my Prusa i3 .... not doing so good so far, still lot to learn.
I'm testing with printout of dice , comes out size about 20x20x20 mm
a) bottom layers get like a bit collapsed , see pic 002 , the bottom there is to the right side
b) top layers get not totally filled up, see pic 004
Been trying to lower bed temp from 110 Celsius down to 90 , at 90 it start failing to get first layers to attach ... so I went back to 110
Any ideas make me happy

www.sidhabo.org/div2/graydice.zip

Ha det gött
Bosse


Prusa i3 Reworked, Delivered March 28 2014, RAMPS 1.4
Göteborg, Sweden
Re: Prusa i3 bad bottom and top layers
May 25, 2014 03:06PM
I'm really not an expert, but it looks like on the lower layers the printer is pushing too much plastic, so it becomes somewhat wider.

I'd try 2 things:
1. Try to print a walled cube - just 4 walls - you'll get to see the bottom anomaly better (if there is one).
2. Try to print with a raft. This way the anomaly might be all in the raft (but usually a raft is only 2 lays or so).

Regardin the top part: What software did you use to slice this cube? Did you try to view the gcode to see if it's reasonable?
Usually you should get diagonal lines at the top. Even if you're not using enough plastic, there would be gaps between the
diagonal lines, not the kind of mess shown in your picture.

HTH.
Re: Prusa i3 bad bottom and top layers
May 25, 2014 03:34PM
Thanks for info Barakori
1 Do you know where i can download stl file for walled cube ? I don't do 3D design myself ...
2 Hm, is that something you have to add in 3D design , the raft ?
I'm using Repetier V0.95F with integrated Slic3r ... so Repetier is providing most basic settings.
I have just tried some change heated bed temp and turned off the auto fan. + using Z offset to get best distance for first layer.
With auto fan I get just shit result winking smiley

Downloaded the dice stl from net that I'm using for calibration of my print quality

Ha det gött
Bosse


Prusa i3 Reworked, Delivered March 28 2014, RAMPS 1.4
Göteborg, Sweden
Re: Prusa i3 bad bottom and top layers
May 26, 2014 10:19AM
one depends on what your printing with hopefully abs with a bed temp of 110 because pla its 70, if using pla then get a fan on it not the first layer but after that, too much plastic your top layer shows signs of too much plastic and the nozzle drags the excess when trying to print the layer


Check my rubbish blog for my prusa i3

up and running
[3dimetech.blogspot.co.uk]
Re: Prusa i3 bad bottom and top layers
May 26, 2014 04:13PM
Thanks for info Chris. Yes I print ABS. Will check on my extuder calibration ... see if that is still correct.
Ha det gött
Bosse


Prusa i3 Reworked, Delivered March 28 2014, RAMPS 1.4
Göteborg, Sweden
Re: Prusa i3 bad bottom and top layers
May 26, 2014 04:41PM
Have your bed at 110c for the first layer, then drop it down to 80-85c. This will reduce the inward curve of your vertical walls.
Re: Prusa i3 bad bottom and top layers
May 26, 2014 04:54PM
Quote
Dirty Steve
Have your bed at 110c for the first layer, then drop it down to 80-85c. This will reduce the inward curve of your vertical walls.

Yes, been at that a bit. Trying auto cool function in Reperier. I'll have a go with just manual control of the fan. Have to rig my fan something better.
At the moment it cools the hot end too much when activated.
Thanks for feedback winking smiley
Ha det gött
Bosse


Prusa i3 Reworked, Delivered March 28 2014, RAMPS 1.4
Göteborg, Sweden
Re: Prusa i3 bad bottom and top layers
May 27, 2014 03:50PM
Ok checked extruder feeding calibration. It was fine. Managed to shield fan flow from hot head so it's not affecting at all now smiling smiley
Tried manual cool with fan while printing but no real luck there. Still that kinda flat down of the bottom layers ;(
Just struck me that all since start trying to get good printing I have used the sama stl file for a dice that I downloaded from internet.
Could it be some bad in the stl file ??
Has anyone got some known good stl file to share for me to try out ? Getting sane print out quality ...
Like a solid or hollow cube maybe .. or what else good to get a hold of my printouts.
Ha det gött
Bosse


Prusa i3 Reworked, Delivered March 28 2014, RAMPS 1.4
Göteborg, Sweden
Re: Prusa i3 bad bottom and top layers
May 28, 2014 08:55AM
Just google hollow box or thin wall cube tests theres loads calibrations on thingiverse


Check my rubbish blog for my prusa i3

up and running
[3dimetech.blogspot.co.uk]
Re: Prusa i3 bad bottom and top layers
May 28, 2014 12:28PM
Thanks Chris, that was real easy to find hehe

http://www.fabfabbers.com/models/id/53/reprapcalibration-by-fugazza

Ha det gött
Bosse


Prusa i3 Reworked, Delivered March 28 2014, RAMPS 1.4
Göteborg, Sweden
Re: Prusa i3 bad bottom and top layers
May 28, 2014 08:22PM
sorry i just went on thingiverse searched single wall box it came up with this single wall box lol

Edited 1 time(s). Last edit at 05/28/2014 08:23PM by chris33.


Check my rubbish blog for my prusa i3

up and running
[3dimetech.blogspot.co.uk]
Re: Prusa i3 bad bottom and top layers
May 29, 2014 07:35AM
Quote
chris33
sorry i just went on thingiverse searched single wall box it came up with this single wall box lol
Thanks , that look like a decent challenge to get printed. When I get that done I'm probably calibration expert for Prusa smiling smiley
Ha det gött
Bosse


Prusa i3 Reworked, Delivered March 28 2014, RAMPS 1.4
Göteborg, Sweden
Re: Prusa i3 bad bottom and top layers
June 08, 2014 01:48PM
Hi doing some more work Adjusting my extruder step feed rate.
Was at 746 and now I think I get better result with value 670 (less plastic feeded)
Just not happy with the top layer ..
Left one in attach was with 746 and right one at 670
None is real good to me ..... or is this the best you can get for top layer ?
Ha det gött
Bosse


Prusa i3 Reworked, Delivered March 28 2014, RAMPS 1.4
Göteborg, Sweden
Attachments:
open | download - stlRound 003.JPG (172.4 KB)
Re: Prusa i3 bad bottom and top layers
June 08, 2014 02:02PM
Just another observation I don't understand.
Printing first layer there is always first a real thin perimeter printed, after that kinda the "real" first layer get printed
Like I have my first layer hight at 0.5 mm other one's at 3
So what height is this first thin layer printed at ? .... compared to the "real" first layer with infill and all ?
Ha det gött
Bosse


Prusa i3 Reworked, Delivered March 28 2014, RAMPS 1.4
Göteborg, Sweden
Re: Prusa i3 bad bottom and top layers
June 09, 2014 03:42PM
the very first layer i have at 0.35 and the rest at 0.4 i always keept the very 1st layer at 0.35


Check my rubbish blog for my prusa i3

up and running
[3dimetech.blogspot.co.uk]
Re: Prusa i3 bad bottom and top layers
June 09, 2014 04:19PM
Quote
chris33
the very first layer i have at 0.35 and the rest at 0.4 i always keept the very 1st layer at 0.35
Oki, I'll try that Chris smiling smiley
Ha det gött
Bosse


Prusa i3 Reworked, Delivered March 28 2014, RAMPS 1.4
Göteborg, Sweden
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