Failed Print, Near End, FIXED, but surface quality changes near end

We just received a replacement printer, upgraded with Form1+ components, and tried our first print. It went well until near the end of it. Printed from Windows 7 pro 64-bit, using Preform 1.5.2, and updated firmware, with slightly decreased support density and point size. I wish Preform would tell me what the supports settings were when I open the file because I don’t remember the exact values. I scraped and combed over the resin tray after and it looked good, except for the lump of resin left over from the fail. I checked the mirror and it looks fine, nothing stood out on that side, except for one spec of dust that wouldn’t blow off with my air can. I guess I could try to wipe that off, but it looks like the print failed in two spots. Any guess as to why this one failed in this way?

Some close ups, Looks like the fail started in a grooved area of the object. Also, some of the supports have some bends in them.

Photo of the mirror (looks kinda dirty to be a brand new mirror):

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From what I can see of your supports it looks like the edge is supported very well. But maybe not the failed area, which is not connected to supports yet at the time it failed. It’s a bit tricky thinking about a part in layers, but open your file again and scroll to a layer in the failed area and I think it will make sense.

I would add some supports manually in that area and print again. I think that will do it. Your mirror is getting dirty, but I don’t think it is to blame. Good luck.

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Josh makes some great points. Perhaps an additional manual support or two in that area may solve the problem.

Your mirrors are certainly dirty and should be attended to. Because most of the print came out okay, it doesn’t seem like they’re to blame here, but I’ve certainly had prints fail far worse than yours with mirrors equally dirty. I’d submit a ticket to customer support and they can connect you with the resources and information to appropriately clean the mirrors without damaging the machine.

Great, thanks for the replies. I will clean the mirror today (we’ve been given instruction before), and try printing again with added supports in the problem areas. I’ll let you know how it goes.

Sorry guys, my next print failed again. I cleaned all the blue smudges off the mirror, then I added supports to the problem area and moved the part to a different location on the build platform. It actually failed sooner this time.

As you can see, I canceled the print before it finished. What’s interesting is the supports I added failed first, before the model began failing. I’ve scraped and combed my resin tray after every print, and this is only the third print on this tray. I’m out of ideas. Is my part just too big?

Maybe resin flow is the problem, was the tank nice and full or kinda low? Sometimes the resin does not push itself inward fast enough on large prints when the tank is low, or if the printer is not level.

Thanks @JoshK, the resin flow idea makes sense. I’ve opened a support ticket and they are basically in agreement. I sent the model to them to see if they can figure it out, and I will let everyone know if we do, and why.

I’m waiting to hear back from support. They must be having some trouble with that model. In the meantime I tried a couple more prints.
Print 1: Tried the same object again, with a more vertical orientation so their wasn’t so much support structure, but it failed in nearly the same place.
Print 2: I printed an object about half that size, and it printed well, no failure.
Print 3: I printed a different object almost as big as my failed object, and it failed too, near the end. I canceled it before it finished. Here is a pick of the new object:

How old is the resin tank? As they age the resin sticks to it better and makes for a harder peal. Also, check the bottom of the tank carefully for smudges.

The resin tray has been through 6 prints, and it doesn’t seem to have trouble sticking during the peel process like my last couple trays did (you would actually hear the part pop off the tray). The base of the tray looks clean. We just received it a couple weeks ago, its one of the next gen trays made in the orange plastic.

It seems to print so nice then fail near the end of your large print. I only have one idea left. As these printers run they heat the resin more and more. For a print that large the resin would be getting very warm near the end, and that may cause this. If support doesn’t have a better idea move the printer to a basement or other very cool room and print again.
I do NOT recommend pausing the print while it cools as this always messes up the print. I also don’t think a fan is a good idea since you would probably introduce dust through the seams in the printer body.

@JoshK, I think you are on to something with the heat idea. I just looked at each of the failed prints through a loop and could tell that the layers near the failed area become less uniform. I can see wrinkles in the resin layers. I noticed that the finish near the failed areas look more matte, probably because of this effect. We currently have our printer on our desktop in an air conditioned office, but some days it’s a little warmer than others. We do have a window, but it is coated, and I don’t feel any heat from it, even though I sit near it most of the day. If it is a heat problem, I hope Formlabs find a better way to cool the printer components during the print. I can’t think of any machinery or computer that doesn’t have some sort of internal cooling mechanism, so this certainly seems lacking in the Form1. In the meantime, I need to figure out how to print in a cooler environment, maybe our server room. What do you think of attaching ice packs to the printer?

Ice packs might work if they last long enough. Maybe you can even get one on each side behind the tank. It’s the resin you want to keep cool. When the print finished you can dip the backside of your finger in the resin to feel it’s temperature.

Hey guys,

While I’m not sure exactly what is causing your print failure, in general it is better to print at room temperature, cold temperatures can sometimes cause failures. An air conditioned office should be fine, but I wouldn’t recommend putting ice packs in your printer- it won’t help the print, and you don’t want to get condensation everywhere. Sorry I can’t be more helpful, just wanted to let you know that cold temperatures do have an adverse affect on many prints.

Follow up question here, what would be causing the resin to warm up? Is it soaking up heat from the laser? I’m going to try a test print on Monday and tape a thermometer to the side of the resin tank so I can see what the temp change is.

@Erika_Tsutsumi, Reality is having an adverse affect on his prints, LOL. You are probably right Erika that cold would be bad. But all we are hoping to do is offset the heating effect so the resin STAYS at room temperature.
@Christopher_Hanks, I think most of the heat delivered to the resin is from the laser beam itself. It’s like using a magnifying glass to burn something. All the laser light energy gets converted to heat energy after use, except for the very small percentage that escapes the UV shield. And of course laser diode bodies get quite hot during operation too, requiring heat sinks radiate the heat into the air. Even circuit boards radiate heat. If the printer consumes 60W of power from the wall, then the sum of the heat created by the ‘system’ is the same as a 60W space heater.

This might be a stupid question, but have you considered that you just may have a bad bottle of resin? Have you tried printing the part with black resin?

I would like to see the results of a different resin too.

Hi folks,
We are presently experiencing a turn of luck in our prints. The last 3 came out great. I am printing one more big one, and I will let you know how it turns out tomorrow, with pics. The only thing we changed was the resin, we are now using clear. Also, I haven’t been able to get a thermometer to test the resin temp, but according to a quick finger test, at the start and end of a print, it felt like the resin was warmer near the end.

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I was 99% sure it had to be a bad bottle of resin.