Please Help! Prints repeatedly partially failing


#1

I am very familiar with FDM printing but new to SLA. I have been trying to print this one part but it has repeatedly failed.

Screenshot%201
Screenshot%202

I have printed much larger and more complicated parts on my Moai without any issue until now. Here is what I have tried so far for troubleshooting.

  • Rebuilt part using different workflow (made in Fusion360)
  • Reformatted SD card and updated Moai firmware (using SD card that came with the Moai and reformatting using windows)
  • Processed stl through Cura, Asura3D, and Meshmixer to make sure STL is good, (both before and after adding supports)
    -Altered location and orientation
    -Used multiple slice settings in both Asura3D and Cura

-Different combinations of the above. I have ran this many times all to similar results, as seen here

I have even run some basic cylinders with the same external proportions as the piece at various locations of the print bed to make sure it was not some sort of hardware failure/dead spot. All printed just fine.

I am at my wits end with this. I purchased the moai specifically to prototype this part and it is the only print I have had fail out of the various geometries, sizes and resins I have run in the last two weeks. (this is by far the simplest piece I have run)

Does anyone know what is going wrong?


#2

resin type? laser power?


#3

Sorry to hear your issue, here is a survey we use to help us get as much info as we can from user so that we could provide best solution. Even if you might have provide some info already, please answer the question for the completeness.

support question:

Room temperature (best to be >25C):

What type of resin:

Build plate type: (Standard 1-piece / easy to level)

Vat: (Silicon vat / FEP vat)

What type Vat: (Peopoly Original vat, Recoated Peopoly vat, custom vat made by user)

Leveling measurement:

A, B, C, D (example 10.9mm)

Firmware version:

System Setting is default per Peopoly recommendation? (Yes/No)

Laser Power:

Z-reset position:

PM Motor Speed:

Z Follow Speed:

Software used to slice?

If using Asura,what version and profiles

If using Cura, what version and Profiles:

Infill %:


#4

I am guessing that the failure is occurring around the incut on the “barrel” feature. Is this correct? It may be that the incut is weakening the structure and the “green” resin is then failing/delaminating. You may need to change the orientation, the laser power (unlikely), or the design.


#5

I just got the peopoly heater and a new SD card ( Transcend 32GB SDHC Class 10 UHS-1) and the print ran fine twice. Now I have been repeatedly having the same issue again where part of the print just fails. It happens with all of my prints, different geometry too.

Weird thing is, I printed “Part A” which came out perfect. Then printed “Part B” which also came out perfect. The went to print 3x of Part A at once, one came out fine and two failed in the same manner as all the images above. Tried to print 2x of Part B both of which failed the same way.

Here is my info:

Room temperature (best to be >25C):

  • Using peopoly moai heater so I assume 25 to 35C.

What type of resin:

  • Photocentric Clear Hard

Build plate type: (Standard 1-piece / easy to level)

  • Standard 1 piece

Vat: (Silicon vat / FEP vat)

  • Standard Clear Acrylic Vat

What type Vat: (Peopoly Original vat, Recoated Peopoly vat, custom vat made by user)
-Peopoly Original Vat

Leveling measurement:

A, B, C, D (example 10.9mm)
-All approx 10.7(have had no issues with sticking to build plate)

Firmware version:
-V1.16

System Setting is default per Peopoly recommendation? (Yes/No)
-Yes

Laser Power:

  • 58

Z-reset position:

  • 1877

PM Motor Speed:

  • 12

Z Follow Speed:

  • 10

Software used to slice?

  • Asura and Cura, to the same result

If using Asura,what version and profiles

  • 2.2.0

If using Cura, what version and Profiles:

  • 3.6.0

Infill %:

  • 100%

#6

What do you mean by “incut”? It seems to be failing randomly in different areas.

I have tried changing the laser power, piece orientation, and tried completely different parts, all to the same result.


#7

Photocentric Clear Hard

Laser power tested at 57 and 58, both were working fine before this issue started happening but I noticed slightly better results at 58.


#8

The incut is the divot in the upper portion of the tube. However, looking at the images, I think the thinner walls at the “bottom”…build plate may be the issue with this print. I would try reversing the orientation.

The issue may also be the resin. I have never used Polycentric, so I cannot comment on its properties… particularly the strength of the green resin.


#9

Id guess the resin isnt curing properly as it looks very blobby and jelly like.
before killing yourself and overly tweaking the machine Id try running a print with a bog standard peopoly resin if you have some,
Upping the laser power you say worked a bit, may be you need to go higher still, although be wary of the life span of your VAT…good luck!.


#11

the print looks a bit over cured, try to lower the laser power to 56, see how it goes


#12

Here is the print run three times, from left to right power level 58, 57, 56. Same gcode/placement/etc.

On the third print there was extra support material as pictured below. I pulled up the gcode in Cura, straight off the card, and there is no support material there.


#13

I have tried multiple orientations, 180 degree flip and various angles. And for the form, it is a straight cylinder.


#14

I see it. The images of the STL must have been for something else. What is the “surviving” portion’s resin like? Solid? Soft? Are you finding pieces in the vat? Do you stir the vat or strain the resin after a failure? The last thing I can think to do is inspect the PDMS for fogging or fused resin and then observe the laser during a print. Look for flashing or variation in the beam intensity. However, I don’t think that that is the issue.

I suspect it is a resin issue, the jagged, melted edges are atypical for an SLA printer failure. Usually, the print just stops or fractures along a layer line. You may want to reach out to Polycentric, they may have some tips or experience with this.


#15

i agree with @Paradoxical_Cat , the resin is not initially made for the Moai, ask Polycentric to see if there’s anything wrong with the resin


#16

hi @stevenk

It is the Photocentric clear hard? We have not print with the resin in house but some of our users are having problem with it. Here is a snap chat from our Facebook group:
image

you can find the thread by searching photocentric. I am not sure what to help you since you are running it at optimal set up already. It is likely the resin cannot handle SLA peeling and broken up during layer change.