Prints everything... except the center

#1

I am printing several duplicate prototype parts by multiplying/copying them in a 3D CAD program then uploading them to Preform. In Preform, I auto-generated supports.

The problem is, everything prints fine except the center of the platform. Which is odd… because each part is exactly the same so if it could print the others, why not the center? There were fallen, half-completed parts in the resin tank as well. This has happened twice-- the first time, however, the resin tank came out uncluttered. It seems that the supports are still built at the center though. The printer is fairly new but we suspect it might be from a faulty laser? Could you help me diagnose this issue? Thanks!

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Printer settings:

  • Clear Resin V4
  • Layer thickness 0.05 mm
  • Support density 0.77
  • Support touchpoint size 0.60 mm
#2

Take a look on the glass below the resin tank, it might be dirty and therefore causing to a failure in this particular area.

I will also go on cleaning the big mirror and the Galvo mirror as well. It might be some dirt on the large mirror and to get there you go through the Galvo mirrors so its worth giving them a goid clean too.
Also clean the glass from below.

I can send the instructions how to clean it if you like but I think it will be the best to open a ticket in the support. They also send a free cleaning kit if you like.

#3

I have a similar issue on my Form 1+. After a ton of troubleshooting (new tank, new resin, new build platform, clean large mirror, clean small mirror, clean galvos) we’ve unfortunately narrowed it down to the laser.

Do you see the same problem at 0.1mm layer height?
What if you just print one or two parts in the middle of the platform (and exclude the rest of them)?

Suggest you reach out to Support for cleaning instructions and possibly additional ideas. They can also read diagnostics info from your printer (e.g. the laser power checks).

One other thing you might try is adjusting the Z offset under Fine Tuning to see if you can get adherence to the middle by lowering or raising the platform a few notches.

#4

It’s definitely NOT this, because the vertical (“Z”) adjustment is to insure adhesion on the first layers to the build platform. Based on his photos, there is a raft that looks fine, The parts have broken off the supports.

But I think you may be onto something with the laser. You can see that most of the front parts, have pretty bad looking top surfaces, whereas the further back, they seem to get better. That’s an indication of a laser that’s loosing power.

I would try a different profile, one that has longer exposure times, like the Black v1 or v2. A previous Form 1+ I had had a laser problem, and for a while I was still getting some prints done by doing just that printing grey v2 while using the Black v2 profile.

On a Form 2, he may have to turn on Open Mode to achieve that.

#5

Thanks, I wasn’t looking closely enough at those supports. @echang1365 is that one giant “uber-raft” covering your whole build platform, or are those mini-rafts (supports that connect to small islands on the platform)? It looks like the former to me, but I want to confirm.

I agree with @Dudemeister the Z-Offset thing is unlikely, but in fairness I’ve had Support suggest it to me for other symptoms I thought weren’t due to adhesion. Probably because we were running out of anything else to try.

Over-curing by using a stronger laser profile is a great suggestion. Here’s a graph that gives an idea of relative laser exposures used for different materials.

I’ve done that in the past to tease a little more shelf life out of old Standard resins. You can use Open Mode, or if you really want heat and wiper, you can trim the orange shipping cap and leave it covering the bite valve on a Black cartridge, install it, install the Grey tank, and tell the printer it’s now a Black tank. But you DIDN’T hear that trick from me, and I wouldn’t try it on an in-warranty printer (FL would not approve).

#6

Did you filter the resin after the first failed print? If you didn’t it would explain the rough surfaces on these items.

Is this 49 pieces on a single raft? I’m assuming that printing a small number of these things in the centre of the tray works OK? If this is true then the fact that some of the supports have printed suggests that you are overloading the peel mechanism, and you would have more success with less pieces per build.