UPO sightings / Unidentified Printed Objects

The photo shows our first print after upgrading the FW and Preform to current release.
It looks like a delaminated layer that was captured. Parts came out fine.

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We also had strange artefacts with Tough since the mid december 2017 update. What we’ve seen is that after we remove the part from the BP, the raft features areas that are missing a bit, which we tend to find in the tank afterward. This looks very similar to what you just showed. EDIT : to clarify, the missing bit I’m talking about looks like de-laminated layer, but it’s a few tenths of mm thick, definitely more than one layer.

I will be using some Tough V4 this week, will update is anything comes up.

The raft also seems more brittle and tightly adhering to the build platform after the updates / same tank of resin.

Does your UPO match the shape of the actual printed raft? It looks like it might be a bit smaller which could mean that it’s an artifact from a previously failed print. When you see UPOs like these, it’s best to filter the tank to ensure that there’s no cured resin left over from previous prints.


Not sure if this is related or not. This is my second print with Durable, first one came out fine. I was shipped Durable V1, dated June 2017 from a third party vendor. Resin tank was shaken prior to use. New resin tray was used.

See pic below. The arrows point to an extremely thin layer of cured resin which covered most of the unused portion of the build plate.

As far as I can tell there is no cured resin in the tank itself. I had to use the spatula tool to get the paper thin layer completely off the platform. Glass underneath looks clean, no noticeable resin or dust.

@Frew What would cause this?

Hello Frew - shape matches a portion of the build rafts.

Kevin, I also had something like this while using Open Mode with BlueCast using Gray V2 settings. It happened after a recent upgrade of PreForm and Firmware. The area of cured resin on the build platform was large in comparison to the rafts, and I always filter my resin before beginning a print job, so I know it wasn’t a lingering piece in the tank.

And now this morning I had the first layer not sticking to the build plate ( hanging chads, yes ). Three failures and then I installed a new tank / problem disappeared. Does a clouded PDMS layer reduce the laser power enough to interfere with a full cure of the base layer to the build plate? Seems so. The tank ran 1.5 liters at most. Tanks a lot.

I’ve seen this a few times with Flexible Resin, but this is a bit more pronounced. The base layers of a print have higher compression and exposure, so they’re more vulnerable to scattering outside of the intended boundaries. There can be a few things that cause this, and if you keep noticing artifacts I’d get in touch with our support team.

It might be the case that the raft from a previous print was hanging around in the tank and hitched a ride on the newly printed raft. After these failures, have you been able to filter the tank? That’s an important process to ensure that there’s not any cured resin hanging around as cured particles will increase the chance of a print failure.

Clouding can cause adhesion issues like these, but it needs to be pretty pronounced, and I’m not seeing any errors higher up in your print. Can you take a picture of your tank against a dark surface. Subjectively, the tank can hit a relatively high opacity before clouding starts to have a pronounced negative effect on print quality.

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