Trouble Shooting – Part cured resin (jello) after every print

@Alex_Vermeer you grey prints of the cross are not at all consistent with the was flare presented for most of us. Looking at your laser spot your worst side should either be the front or the back, not the sides. Except @Steve_Johnstone I don’t think anyone has had holes form inside the prints from flare, instead we get build up of extra resin on the surface of our prints and flaking. Your later clear prints look more like flare but being as your grey prints didn’t show normal signs of flare, I don’t think your case is so clear.

@RocusHalbasch, I agree. My case seems to make no common sense towards blaming the laser as the (only) issue… I’ve filtered my resin very slowly the last hour and have refilled the clear resin tank. I’m printing one cross (0.2mm) as we speak and shall post the results of this one once it’s done. hopefully the print will come out without rough spots, or at least consistent to the last one. Otherwise it’ll just get even more complicated :wink:

The result after straining the resin (new thorough method):

As @Steve_Johnstone mentioned. The resin can be ruled out as the cause… This is the result after washing in IPA again:

In case you’re wondering how I filter my resin; I use these two items simultaniously to filter the resin. It takes some time, but atleast it’s thorough!

Apparently this was a shape that was needed by someone (Kevin?) and exhibited a problem, thus it’s being passed around as a common .form to show similarities/differences in prints - correct? Ostensibly, this is to highlight the laser flare effect, but is it also possible the shape and orientation are also playing into the surface quality anomalies? e.g. the position and shape incur a specific type of stress from peeling that may exacerbate the issue.

Q: why does it need to be that tall? seems like it’s using a lot of resin for minimal additional informational benefit. I fully understand the need for a common form that exercises the device and can provide a comparison - just not sure this is the best shape for that.

Also, has anyone tried printing this (shortened, ideally) with the 'X" rotated 45-degrees in the z-axis?

-C

Could a fume hood have the unfortunate side-effect of working to pull dust into the machine at all @EvanFoss?

@ChristopherBarr this shape was arrived at by @KevinHolmes possibly out of necessity but really it just demonstrates the issue with the minimal amount of resin wasted. For the back story on this go here. The tiny cylinders with the double helix in them were also from this thread. They are for the same basic function.

The point for the group was not that we needed this shape it was that it shows a common issue for a lot of our print failures goes back to this laser flare. The tall aspect means that the same areas are retraced over and over by the flare causing it to fully cure resin that otherwise would be uncured or gelled by less optical power.

@ChristopherBarr The airflow in our fume hoods is such that it would only do that when the printer’s cover is open. To do that I have to lift the fume hood window way above the safety limit. Meaning that the airflow is so low around the machine it might as well be squat. Plus I would have to expose the mirror which would require taking the resin tank out. I have had really one 1 occasion to do that because i was scared about cracks in it leaking resin.

Dust prevents laser light from curing things. I have things I don’t want being cured getting cured.

Besides our employee safety people have insisted that I use the fume hood as have my coworkers. It was giving me and my office mates headaches.

OK, I see. Now I understand how the height was part of the test. Thanks. re: the 45-degree question: anyone see what that produces?

OK, thanks Evan.

It turns out that the laser flare happens to be mostly aligned in ether front / back or left /right so the 45 deg would interferer with seeing what is going on.

Mine is not to the front or back. It is diagonal.

@RocusHalbasch

I assume you have printed the crosses at a 45 degree angle then? Would make a lot of sense.

@EvanFoss, I believe you still have the model of the cilinder with the double helix. Do you mind send me that model to see what happens there? It seems that the laser really only has an effect on very tall prints (obviously). I’d like to see what happens on that cilindrical model that’s only a few cm’s tall.

Thanks

@Alex_Vermeer one last clutch at straws diagnosing your bubbling issue - how much resin do you put in the vat for printing? You should fill it to the max to avoid bubbling - so that as much as possible - the part printing surface does not lift above the surface of the resin into the air during peel.

@KevinHolmes, I fill it up to the fill line. The part definitely does not lift above the surface during the peeling process. Thanks for the advice though.

@Alex_Vermeer - well looks like there’s definitely something else at work - I presume you’ve opened a ticket? keep us appraised of progress?

Yes @KevinHolmes, I have opened a ticket and keep you all informed on the progress or possible solution!

@Alex_Vermeer The file for the double helix is not mine. it is from this post

My apologies. @RocusHalbasch. I’d like to ask you the same question then :smile:

I believe you still have the model of the cilinder with the double helix. Do you mind send me that model to see what happens there? It seems that the laser really only has an effect on very tall prints (obviously). I’d like to see what happens on that cilindrical model that’s only a few cm’s tall.

Thanks

@KevinHolmes & @RocusHalbasch I kind of think we should start a thread just for posting files people use to test the corner cases on the printers and not photos of the prints them selves. I would do it but this is not my handy work.

That’s a great idea @EvanFoss, except I think that any new thread are automatically closed after 15 days. Perhaps @Sam_Jacoby could override that for something like this.

If not, I would be happy to set something up on YouMagine that we could all link or point people to to??