Banding, Ghosting, stepping lines


#1

Hi all,

I know there are a few other threads about this but not wanting to pollute them creating a new thread instead.

I have gone through the other threads to see if there was anything obvious in there but I am not sure if this is mechanical, slicer or interference related.
I verified all bolts, all seem thight. Verified vat, I had to put some additional cardboard as the vat was able to move left and right for the latest vat, other vats have always been secure but seeing the issues across all the vats I have used.

Cables all plugged in ok. Removed the acrylic plate above the laser to see if it made a difference but no difference.

I have tried 2 different sockets around the apartment, had it in its usual location on a small elevation and sitting on the floor directly.
I have it with and without heater.
I have double checked all bolts and tightened them as much as I could.

On the 3rd and 4th photos it even looks like the wheel that is behind the beam has a ghosting effect on the side of the beam.

I do not see it on the ring that is pre-sliced so I am leaning towards the slicer as that is the only thing I have really changed in the last few months.

I have attached some photos at the bottom.

Room temperature (best to be 25C):

  • Using official Peopoly heater (arrived last week), sitting anywhere between 30 and 35. Room itself is about 24.
    What type of resin:
  • Standard Blue as well as HiTemp Gray
    Build plate type:
  • Standard 1-piece
    Vat:
  • Silicon vat (seeing the issue across at least 2 vats)
    What type Vat:
  • Peopoly Original vat
    Leveling measurement:
    A, B, C, D (example 10.9mm)
    10.71, 10.70, 10.72, 10.70
    Firmware version:
  • SLA-125 v1.18
    System Setting is default per Peopoly recommendation?
  • Yes
    Laser Power:
  • 58 for Blue, 50 for HiTemp
    Z-reset position:
  • 1880
    PM Motor Speed:
  • 15
    Z Follow Speed:
  • 2
    Software used to slice?:
  • Asura
    If using Asura, what version and profiles:
  • 2.2 currently, seeing the same with previous versions. 40um, 60um, 80um.
    If using Cura, what version and Profiles:
  • N/A (tempted to try 3.6 instead of Asura to slice as I did not used to have this)
    Infill %:
  • Default


#2

Only thing I just noticed is that I had Cura 3.4 installed, not sure how Asura bundles cura but removed the 3.4 and installed 3.6.
Sliced the 2nd model again with Cura 3.6, see what does. There is a difference of 2Mb between the Asura sliced and the Cura sliced version (116 for Asura, 114 for Cura)


#3

Stepping line problems can be caused by the software, try Asura to slice
For the other problems, try full reformat the SD card, remember to save your files before formatting.


#4

Thanks for that, Asura is actually my default go to software for supports and slicing :slight_smile:
I wanted to rule out the software being the cause and as such tried Cura as the slicer but I am seeing the same issue there.
And same thing for the supports so have tried a few other ones as well and no luck either.

I currently reformat the SD drive before every print so that would not be the problem either.

I am opening up the printer again today and going through the http://wiki.peopoly.net/doku.php?id=moai-checkup a third time to make sure I didn’t miss anything there but I am afraid this might be leaning towards hardware?

Is there an easy way to see if the screw is bent?


#5

base on the sifts random and large block, we think it is some kind of mechanical issues. it is usually something that move the vat out of position during a layer peel (beginning of the layer shift) and then after a few layers, it snap back to the correct place. Focus on the areas that are movinging during layer change (the rod under the build platform, the pm motor)

you also have higher than more users’ z-reset at 1880 but since your leveling is around 10.7mm it shouldn;t affect you.

Let’s do this. Lower pm motor speed down to 10 and see if the effects improves. This lowers the layer peeling force .


#6

Hi @TheCaveman, I have a few questions concerning the lines on your prints. Are the lines appearing on X or Y? Or are they appearing on both directions? Are they at random levels on each print every time?


#7

Thanks again.

I did a few things today. I re-opened the printer completely, tightened all of the screws as much as I could, going through that checklist throughly I noticed that the vat tilt mechanism wasn’t quite centered, there was enough space left and right but adjusted it to be as much in the center as possible.
I rewired things so that power and data cables are no longer touching.

I noticed a while back that the vat could wiggle a bit left and right/up and down and had put some cardboard to hold it in place in one corner, I removed that and added it to all sides (see image 1) with that in place the VAT is as tight as it can be (It adds about 1mm in thickness). (I did not notice this with the first vats I have used in the past but noticed it on the last 2).

Since this is pushing down the vat I did a re-level and that at the same time removed the need for the Z-reset at 1880. I now have A: 10.69, B: 10.67, C: 10.70 and D: 10:69 and a z-reset at 1877.

I did a print with that (Image 2), sliced with Azura 2.2, 60um layer height and PM motor speed at 15 (image 3), unfortunately that only printed one of the items as I forgot I had to select all 3 of them to print. The one in image 3 is the one that is highlighted in image 2/perpendicular to the door

I then lowered the PM motor to 10 and did a reprint (Image 4 is the same orientation as image 2, image 5 is the parallel to the door and image 6 is the one standing up straight).
I can see the banding on both the X and Y axis but only on the flat surface, the curved one seems to be fine and I seem to only see it where the supports connect (some of them broke off as I tried to remove it from the build plate).


print%20orientation
PM motor speed 15, perpendicular to door , 45degree angle left side

PM Motor speed 10, perpendicular to door 45degree angle left side

PM Motor speed 10, parallel to door 45degree angle left side

PM Motor speed 10, parallel to door 45degree angle, right side

PM Motor speed 10, parallel to door, standing straight

PM Motor speed 10, parallel to door, standing straight

The ones standing up straight seem to have the biggest bumps at the bottom but seem to get a lot better towards the top.
On the parallel to door with a 45 degree angle, the right side seems to be smoother than the left one. the supports on that side are not quite on the edge of the test object.

Any further thoughts?
Thanks for the help so far.
Jozef


#8

that is a strange looking bump. almost like a fail print: can you show this spot

image

like how the support is connected to the object. it seems the support missed the edge.
please show the support in Asura as well.

a way to check it to print the object straight up without base or support (it seems like it has a flat bottom)


#9

It looks indeed that it was missing the corner support there. I guess that would explain the blob.
I’ll print it flat on the build plate tomorrow and let you know how that goes.

Thanks again,
Jozef


#10

After thightening, fixing supports and going back to standard gray instead of the hiTemp it looks like all my issues are resolved.
Even with the heater I think, for the size of things I am making (ie: car axles at 1:87 scale), that the high temp might just be too thick.

Thanks for the help with this Peopoly. Hoping you are having a great new years celebration!