Help! Why did this print fail? total mess!

Hey guys,

I’m wondering why this print failed. It has printed fine 2000 layers (of the 3000) and suddenly stopped printing a part which was pretty solid compared to the rest.

Perhaps based on the photo’s you can tell me how this happed with your experiences?

I know the back part of the Iphone cover is very thin (you can see through it eventhough it’s white resin. However it seems that the print didn’t fail because of that…

Any ideas?


Likely not enough support in that region. One thing I’m noticing is the amount of sunlight able to hit the resin - you should pull that shade when opening the lid. Also, if you’re using super hi-res (25um), try it again @ 100um.

Thanks for the reply Christopher.

My shades are closed all the time, and pointing upwards to make sure that most of the sunlight is blocked. Luckily glass blocks UVB as well, so that little amount of UVA that might hit the resin shouldn’t really harm it. Besides that I make sure I keep the lid open for the least amount of time possible.

Regarding the print; it’s printed at .05. and I don’t think printing it at .1 or any other resolution will help because after removing the print, I noticed it had trouble with the thinnest part on the back which was about 600microns thick. Notice where it doesn’t go in a straight line anymore…

Apart from that I now have ghost marks on the tray which don’t help. Especially because the print covers the whole buildplatform.

Probably the main lesson to learn here is that I should use a lot more supports, however, as you can see in the image, Preform doesn’t show any red spots where it might have issues printing. So it should have printed fine…

@Alex, you probably answered your own question; “ghost marks on the tray” - it looks like you stopped the print shortly after it failed, so it seems likely the tray silicone was in the process of clouding during your print - causing the failure.

The silicone in the resin tray is only good for some 1000s of of layers of printing before it clouds, how many depends on your resin, and to a degree how you treat it between prints (mixing settled resin pigment and massaging silicone with spatula) I’m not even getting 1000 layers before clouding using Madesolid kickstarter white resin, but I definitely get more than 5000 with FL clear and grey, although FL white was not as good.

In any case (assuming the ghosting won’t rub off with some gentle spatula massaging) you need a new tray, or to resurface the silicone in the tray yourself - it’s not difficult, all you need is some “optically clear” (key phrase) silicone potting compound - as used for solar panels or led lighting. There are plenty of threads on the subject…


Hey Kevin,

I guess you’re right. Luckily I ordered some Sylgard 184 already because I knew eventually this was going to happen. Hopefully it will arrive soon so I can change the silicone layer!

I must say I’m shocked about the 5000 layers with FL resin. That would be 2 large prints or only a handful of small prints before you hit that mark. That would’ve meant that when people hadn’t discovered how to create a new silicone layer and just had to buy a new tray, this add extra costs of €31,- for a big print or lets say €10,- for a small print, just for devaluation of the tank… Of course you’re able to play with the space on the build platform and sometimes are able to print on a different spot than the last print, but not often…

What is the actual reason for ghostmarkings? Because most of them appear by failed prints, so is that due to the laser curing a part that is already cured and stuck to the tank? Or are there different reasons for it clouding?

Hi Alex -

I did say “at least” 5000, and that FL white was worse than the other FL resins - but I haven’t been taking notes. There are other threads on how long the silicone PDMS lasts and why it degrades. At least one guy was taking notes on how many layers his silicone was lasting - so if you track that one down you’ll get better guidance - I was being conservative.

As to why the clouding happens, I don’t think we have a definitive explanation yet - certainly FL haven’t weighed in on the subject. The last thread I saw mentioned heat from the laser. Also like your suggestion, other threads report failed prints causing faster clouding. However I haven’t observed this effect myself, I can’t help wondering if there’s some confusion of cause and effect there - since clouding causes failure, so naturally you will see clouding around failed areas of prints more often than elsewhere.


It seems to be a different issue perhaps, because I’ve tried printing another model with a different color resin in a differnt resin tank, but this one really failed horribly. so horribly that I opened up a ticket…

This was the model I made which I needed printing:

I left the house and this is what I saw when I got back:

What am I doing wrong??..