Inconsistent printing


#1

Hi all,

I am a little perplexed as I did a run of three prints, all worked fine. I then proceeded to print another batch and the part continues to not print consistently. The second half of my print will not print or is warped.

I did not change any settings between batches. I am using the same bottle of resin for all batches (new bottle).

I though maybe the PDMS window was clouding and I would need to increase my exposure time to compensate for the less amount of light coming through. I incrementally increased it and at double the original exposure time, it still would not print.

I changed trays as well, one without a cloudy PDMS and no luck…

Any help or input would be much appreciated!

@scott_chabineau @OwenSmithyman @Owen_Smithyman_321


#2

when you say the second half, do you mean that several layers into the print it starts to fail? That the first layer, burn in layers, and several model layers print OK, but at some point, the print starts to delaminate?

OR - that only half the build area is printing and that one side sticks OK, but the other side fails at early in the print.


#3

@scott_chabineau Yes, several layers into the print it starts to fail. The first layer, and burn in layers are fine, and several of the model layers, but at some point the layers start to delaminate.


#4

What resin are you using?


#5

PR48, standard clear; I purchased from Colorado Photopolymer Solutions.

@OwenSmithyman


#6

Do they delaminate around the same area every time? I would check the geometry in that area.

I have found that delamination can occur if a slice has a lot of surface area OR if there are fully enclosed open areas (see illustration below) and you don’t give it enough time to settle. The resin may still be in motion (squeezing out) when you try to cure it. Try increasing the Wait (before exposure) time by 1 to 2 seconds ( “ModelApproachWaitMS” if editing in Brackets)

A less likely reason is too much exposure time - this can happen between the first layer and burn-in or the burn-in and model layers if the difference between exposure times is too much. IE 9 seconds for the first layer and 3 seconds for the burn in layers. The longer exposure times make the layer harder, but the next layer has a harder time sticking to it.


#7

I have that issue now…I am printing communication molds for a tv show and are now (all of a sudden) not printing past the supports…once it hits the part it fails.

One thing about the old trays…you could see thru them and see if your prints fail before it goes thru most of the print unlike the new tray type.

I have had have issues with printing on Print Studio …emberprinter.com always seemed to print better (now that is gone) so I tried it on netfab …same thing.

Changed to a newer bottle of resin (PR48) …same thing
Different tray…same thing
Everything looks clean…uugh!


#8

It is quite frustrating. I am not sure what to do… Have you tried a different resin?


#9

Im going to try the black flexible resin tomorrow…
But I never had an issue printing with PR before
Im going to crack a new bottle tomorrow as well

I am sure its something simple…Im going to clean everything tomorrow to make sure.
Then check all my settings as well


#10

No luck with the black resin for me.


#11

Problem solved…
Changed to the old style tray and cracked a new PR40
printer is back to printing perfectly.

I can only assume it is either the new resin tray windows (they looked clear to me)
or older resin? Im leaning towards the tray…will test


#12

Ah lucky you! I tried the same thing and no luck :frowning:

What was the feature size of the portion that you were printing that was failing? Mine is 150 microns… (I have printed several in the past so I am not sure why this is happening)


#13

Have you tried a brand new tray? PR48 degrades trays over time as the UV blocker absorbs into the PDMS. Note that you can’t actually see this happening – it’s different from “clouding”, where you can see visible changes in the PDMS. So a tray may look fine, but if you’ve been using it with PR48, it will have some degree of degradation. This process happens pretty quickly – if you leave the PR48 in the tray for a day or two, that tray will be unusable.


#14

Hi Owen,

I just received another pair of new trays and it works! I am ecstatic! Thank you for the help!


#15

I store all my trays tipped up on a fixture I printed to let the resin run off the PDMS during storage. This has extended my tray life significantly without adding the hassle of emptying the tray every time.


#16

Hi Scott! What post is this in? Do you have a photo of how you store it?

Thanks!


#17

Sorry for the bogus link before!


#18

I see, that makes sense, I will start doing the same! Thank you so much!

I hope all is well!