Bad top layer  

Re: Bad top layer

You might want to try calibrating you extruder. Search these forums for how.

Also, things to try: Slow down your first and last layer in the slicer, and look at the new Slic3r first and last layer patterns under "infill" settings. Hilbert curve has an interesting result. Search this forum for that, and you will see some photos I posted. (But for small parts like these it might not help much.

Re: Bad top layer

So the top layer fill made a difference.
But as you can see the bottom layer looks bad to me so that was not the ultimate solution.

bottom:
http://imgur.com/DV1u8f9

top:
http://imgur.com/AW339UL

So I reduces the speed and did an extruder calibration. but both things didn't have a big impact.

So what do you guys think? I am happy with any advice on what parameter to tweak!

Re: Bad top layer

why your first layer height is 0.2 and rest 0.15?
change first layer to 0.15
try reducing temp by 10 deg and see if results better

Re: Bad top layer

Is your Z Height set really well? See "Life Adjust Z - my way" thread by Jeff. Read at least the first 5 pages until you get to the V4 of his calibration object. It is really worth your time to do this carefully.

Re: Bad top layer

Thanks guys I will get to it asap.
I have additionally printed this fellow and I still feel that there is a lot to improve...

https://imgur.com/a/BAvuF

Re: Bad top layer

This is an okay first start, but there are things to improve. My guess on this guy is you need to calibrate your extruder, and do a PID calibration.

Here is my starter advice for getting your printer going well, and avoiding some of the common frustration inducing issues.

1) Run the Self Test from the menu. Make sure everything is connected correctly.

2) Make sure PINDA is above nozzle tip by <1mm but above the nozzle. About 0.6mm is a good starting point, which is about the thickness of a credit card. Place a sheet of paper on the bed, and run the XYZ Calibration from the menu. Stay with the machine, and watch it. As it hunts for the calibration points, watch if the paper moves. If it does, STOP THE PRINTER. That means the nozzle is dragging and the PINDA sensor is a bit too high, lower it and try again, but make sure it is still higher than the nozzle tip. Repeat until you have a good XYZ Calibration. (Note the instructions on the XYZ calibration, and make sure the nozzle tip is clean.)

3) Set your Live Adjust Z roughly correct.
a) Set Live adjust Z = 0.00. (XYZ Cal does this).
b) Do a Calibrate Z. (Head must be clean of drips and lumps).
c) Do a Home. This leaves the head at Z=0.15mm
d) Use Setting -> Move Axis X and Y to get in the approx center of the print space. DONT TOUCH Z.
e) Put a piece of printer paper under the head. Printer paper is approx 0.1mm
f) Wiggle the paper while adjusting "Live Adjust Z" (in settings) until the paper just starts to drag on the paper.
g) Back off a bit (50) on the “Live Adjust Z"

4) Load some filament.
a) Make sure the tension screws are about 14mm from the body with no filament in the extruder. (This is looser than is intuitive for most people. Too tight or too loose will cause issues.)
b) Heat the extruder. You can do this with pre-heat or settings->temperature.
c) Use Load Filament from the menu. Continue until you have a nice thin strand coming from the extruder.
d) Cool it back down.

5) Make sure the bed is very clean.
a) Wipe with as pure an isopropyl alcohol (IPA) as you can find. The little toweletts are not enough in my opinion. Use (and re-use) a paper towel and a good squirt of IPA.
b) (If really dirty, you can use Windex followed by Acetone followed by IPA, but that should only happen if you had used glue stick or other things on the bed and want to really clean it off). I do this if I am changing materials.

6) Get your Live Adjust Z dialed in real well.
a) Print using "Calibration_surface_PLA_75x75@200um_v4.gcode" found in Jeff's "Life Adjust My Way" Thread (Read through page 7 or so till you see the .v4 code. Look at the pictures.)
http://shop.prusa3d.com/forum/prusa-i3-kit-building-calibrating-first-print-main-f6/life-adjust-z-my-way-t2981-s150.html
b) Repeat until you have a nice test print - all stuck together and one nice clean sheet.

7) Do the PID calibrations for the bed and the extruder from the calibration menu.

8) Print a few of the included gcode files. Start with the Prusa logo. The gears are a great test and fun thing to have.

9) Start with a few things on Thingiverse that are easy. Learn how to use the slicer of your choice (I like Slic3r, but there are many options and opinions and all have pros and cons). Start with things that don’t need supports. Trust me, supports should come in after you have good confidence in your printer and yourself.

10) Start designing your own things. Learn supports settings. Try different filament types.

BUT THE MOST IMPORTANT ADVICE: Don’t get frustrated. You WILL run into problems. Search this forum. Read. If you can’t find your answer in 10-15 minutes, post a question. This is a very supportive group that will likely get you going again. If you solve the problem, assume someone else will run into that problem as well, and follow up your question with the answer. There are many people who read these and don’t post, and your solution could help them.

Re: Bad top layer

here a first result on the square calibration by jeff:

-672 Z adjustment measured with 0,220 mm. Do the 20µ hurt? Also, -672 sound too much or is it still acceptable?
http://imgur.com/U7BqUe2

Re: Bad top layer

why your first layer height is 0.2 and rest 0.15?
...

I guess because that's what prusa recommends for the first layer (always 0.2mm). all the slicer profiles for the prusa i3 mk2(s) are set up for 0.200 mm for the first layer.
of course the firmware limits the first layer to at least 0.15mm, but not at every printer assembly and every "levelled" heatbed you succeed with this height.

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and please fellows: do not use any picture hosters for posting pictures here. just use the attachment option and attach the pictures as *.jpg file directly.
why ? because this forum acts as a knowledge data base, so that future users could search the forum for older threads and learn from them.
if you use picture hosters, these pictures are not always available and will vanish from older posts as soon as the hosters directories are cleared.
if you use the attachment option, the files will be stored permanently at the prusa server that hosts this forum.

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here a first result on the square calibration by jeff:

-672 Z adjustment measured with 0,220 mm. Do the 20µ hurt? Also, -672 sound too much or is it still acceptable?
http://imgur.com/U7BqUe2

if you've read at least the first 4 sites of my thread, you should have noticed that there is an "optimum" that you need to find (where the layer thickness is the lowest). and as I mentioned in that thread as well: the z adjustment level is just a number, neither too much or too less. so if -0.888 is the value where you've found your optimum, then it'll be the value to go for. if you're getting close to -1.000 you should think about lowering the p.i.n.d.a. a little bit, just to make sure that the probe triggers at all environmental cirumstances (especially temperature) and you 9 point calibration sequence won't fail by digging the nozzle into the heatbed.

Re: Bad top layer

2) Make sure PINDA is above nozzle tip by <1mm but above the nozzle. About 0.6mm is a good starting point, which is about the thickness of a credit card. Place a sheet of paper on the bed, and run the XYZ Calibration from the menu. Stay with the machine, and watch it. As it hunts for the calibration points, watch if the paper moves. If it does, STOP THE PRINTER. That means the nozzle is dragging and the PINDA sensor is a bit too high, lower it and try again, but make sure it is still higher than the nozzle tip. Repeat until you have a good XYZ Calibration. (Note the instructions on the XYZ calibration, and make sure the nozzle tip is clean.)

So it didn't catch the paper in the first place. Fine adjustment is done now via live Z adjustment

Re: Bad top layer

if you've read at least the first 4 sites of my thread, you should have noticed that there is an "optimum" that you need to find (where the layer thickness is the lowest). and as I mentioned in that thread as well: the z adjustment level is just a number, neither too much or too less. so if -0.888 is the value where you've found your optimum, then it'll be the value to go for. if you're getting close to -1.000 you should think about lowering the p.i.n.d.a. a little bit, just to make sure that the probe triggers at all environmental cirumstances (especially temperature) and you 9 point calibration sequence won't fail by digging the nozzle into the heatbed.

Well then I try another round substracting another 50µ.

Re: Bad top layer

if you've read at least the first 4 sites of my thread, you should have noticed that there is an "optimum" that you need to find (where the layer thickness is the lowest). and as I mentioned in that thread as well: the z adjustment level is just a number, neither too much or too less. so if -0.888 is the value where you've found your optimum, then it'll be the value to go for. if you're getting close to -1.000 you should think about lowering the p.i.n.d.a. a little bit, just to make sure that the probe triggers at all environmental cirumstances (especially temperature) and you 9 point calibration sequence won't fail by digging the nozzle into the heatbed.

Well then I try another round...

Re: Bad top layer

I have finished the square calibration prints from Jeff:

-0.672 -> 23
-0,697 -> 22
-0,747 -> 31
-0,797 -> 22
-0,847 -> 33
-0,897 -> 38

It seems as if there are two local minima. That's weird right? Structure looks good on both as far as I can tell...
Here's a first try after all the steps from aaron.s5 except PID calibration (Need to find an appropriate cable first):

https://imgur.com/a/UvS6P

Re: Bad top layer

Can one make an assumption of the state of my printer regarding the above printed item? The shape itself looks good tom me but the top layer still doesn't seem perfect to me. Am I right?

Re: Bad top layer

The top layer is really not affected by Z-Height. Just the first layer. To improve the top layer, try: PID calibration.

The Prusa Logo is not a great test of the top layer. Try a calibration cube from Thingiverse...