strange over exposed layer

[thetrickybuddha]

Recently on my Mars Pro I have started getting a layer which is over exposed and creates a single layer film towards the end of my prints. It is easy to scrape off and doesn't damage what I'm doing but it is odd. It does not seem to make a difference if I change resin types which also changes the exposure times as well. Here is a shot of what happens and my printers info. Thanks in advance.

   

   

[MAG_WHEEL]

thetrickybuddha pid='1905' dateline='1596675298']Recently on my Mars Pro I have started getting a layer which is over exposed and creates a single layer film towards the end of my prints. It is easy to scrape off and doesn't damage what I'm doing but it is odd. It does not seem to make a difference if I change resin types which also changes the exposure times as well. Here is a shot of what happens and my printers info. Thanks in advance.

Did you ever find a solution to this issue? I have a new Mars Pro printer that just started doing this on my last two prints as well. I've made no changes to any settings, it just started happening.
   

[cliffyk]

Examine the FEP to determine if it is cloudy, also are you using the printer cover? What sort of lighting do you have in your work shop?

[MAG_WHEEL]

Examine the FEP  to determine if it is cloudy, also are you using the printer cover? What sort of lighting do you have  in your work shop?

Thank you for the reply Cliff. My printer has a red plastic cover that I keep on it at all times except when pouring resin, cleaning or storing.

My studio has 4x 20 watt bulbs, they were off during the last two print sessions (when this occurred) but were on during all of my previous successful prints.

My FEP is tight, clear and clean.

I'm going to try using a different memory stick: in an earlier post you mentioned that the memory stick might cause intermittent issues. I'll post a dedicated thread after another attempt.

Kindest Regards,
Wm

[cliffyk]

I had asked because the odd layer did not look like any artifact of the slicer software I have yet seen, then reproduced by the printer. but rather some blob or puddle at the surface of the resin that somehow got cured by ambient or reflected light. Some "daytime" fluorescent lamps have significant 400 to 410 nm output.

I have seen some weird stuff come out of Chitubox, however it's been blocks and partitions in what should have been open aresa or recesses in the model. Have you tried loading the .ctb file into Chitubox and examining it layer-by-layer o see if the anomaly is in the sliced file? This has been how I found the aberrations I have observed--reloading and re-slicing the .stl have generally cleared them up--though a few times I have had to go back to FreeCad and re-export the mesh; even recreate it on one particularly troublesome component with a 10 mm deep trapezoidal recess that Chitubox insisted on partially closing...

BTW/FWIW this is an inexpensive and fun tool/toy to have about for gauging the spectral content of light sources. observations are somewhat objective, but with surprising resolution and accuracy for a $9.00 high school classroom toy (I used black electrical tape to mask off the slit and narrow it a bit):



Accuracy is claimed to be ±5.0 nm which it seems to achieve:

[MAG_WHEEL]

I had asked because the odd layer did not look like any artifact of the slicer software I have yet seen, then reproduced by the printer. but rather some blob or puddle at the surface of the resin that somehow got cured by ambient or reflected light. Some "daytime" fluorescent lamps have significant 400 to 410 nm output.

I have seen some weird stuff come out of Chitubox, however it's been blocks and partitions in what should have been open aresa or recesses in the model. Have you tried loading the .ctb file into Chitubox and examining it layer-by-layer o see if the anomaly is in the sliced file? This has been how I found the aberrations I have observed--reloading and re-slicing the .stl have generally cleared them up--though a few times I have had to go back to FreeCad and re-export the mesh; even recreate it on one particularly troublesome component with a 10 mm deep trapezoidal recess that Chitubox insisted on partially closing...

BTW/FWIW this is an inexpensive and fun tool/toy to have about for gauging the spectral content of light sources. observations are somewhat objective, but with surprising resolution and accuracy for a $9.00 high school classroom toy (I used black electrical tape to mask off the slit and narrow it a bit):



Accuracy is claimed to be ±5.0 nm which it seems to achieve:

Thank you for the suggestion to review the sliced file in Chitubox: that never occurred to me. You are an excellent resource for newbs like me. Thank you very much.

I collect expensive toys: I'll look into the spectral gauge. I suspect it will be a huge hit with my spouse, the science teacher!

[MAG_WHEEL]

[b]cliffyk 
[/b]
Thank you for the suggestion to reprocess my slice file. I did that and used a different memory card and my print tonight turned out fabulous without any artifacts. Not sure what the original issue was but I had no problems this time.

I did run through the slices on the previous file looking for artifacts and did not find any, however, i will remember that advice as well in the case of any future printing errors.

Hopefully OP will find some solutions here if they are still experiencing this.

Thanks for sharing your experience and happy printing!

WM

[cliffyk]

Cool... Though it is unfortunate you changed two parameters--now we don't know which (the slicing or the card) was the problem.