Peeling Surfaces and More

Hi Community!

I just submitted a support ticket but I wanted to see if anyone else has encountered these Epic Fails as I have.

Surfaces printed that are parallel to the font/back of the printer are nice and smooth… surfaces printed parallel with the left/right of the printer are terribly lined. The surface on the sides starts peeling while in mid-print.  I get perpendicular walls that start protruding through the sides of the print.  Splitting of the print.  Sometimes geometry will just suddenly shift.  Nothing is square.

I’ve tried all the resolutions, white and grey resin.  I’ve probably wasted a whole bottle of grey trying to get one box done for an upcoming show.  I’ll try to keep this updated depending on what I hear back from support.

I currently struggle to complete one acceptable print.

Hi Bill,

That box is huge - the thing with the Form1 is that it’s build envelope is much larger than can actually be filled, suction forces from peeling on parts that have layers with a large surface area will have issues. You can see that your part is having issues before you get to the peeling because the supports change from straight to having pronounced steps - this usually indicates that the peel stresses are too high, because the surface area of a the layer being printed is too large.

Do you have a breathing hole in the top of the box - or is it airtight until it opens out? a breathing hole to let air in during peel might help, but it’s still a huge part, and I’d be surprised to see it print properly.

The cylinders are harder to judge - they seem fairly small, so printing them one or two at a time shouldn’t be a problem. But again - stepping normally means high peel stress, how many are you printing in one go? Are they also closed at the bottom or are they open cylinders? if they’re closed at the bottom then again an air-hole will help a great deal.

Kevin.

Kevin,

The box section you see is 3"x325"x4" and open on both ends, a square tube.  Not as large as the picture looks.  The end caps (4th pic, 5th pic and 7th pic) are 3"x3.25"x2" and shaped like a square bowl, not much bigger than an iphone dock i’ve seen printed.

Tubes are open on both ends and 1.25"x7/8", there should be no suction as there are no cavities.  Hopefully you can see how crappy the surface texture is. printed at .05. Tubes were evenly spaced around the build platform, you can see they all had a shift at the same point so it couldn’t be a weight issue, they are independant of one another.

It’s hard to photograph the white resin but I am including a photo to try to show the edge to show how badly the textures look.

Hi Bill,

So I haven’t seen peeling like that before, but I have seen that stepping in the supports - and it’s always when my parts get too large, and I can hear a loud thunk during the peel process - as the cured layer is separated from the PDMS (the silicone at the bottom of the resin tank) while surrounded by viscous resin.

So I still think that box is most likely too big (but you could share the Form1 file - or the STL?) - simply because the base takes up most of the build platform - and because of the stepping you can see in the supports once it starts printing the part proper. What’s the wall thickness, maybe 1/4in?

As for the smaller tubes - it sounds like you maybe printed them all at once? I know they don’t look like much, but the Form1 really can’t handle a lot of simultaneous surface area during peeling, it’s not about weight, or whether the parts are connected or not - its simply about the cumulative surface area of a cured layer that has to be peeled away from the PDMS, so I expect you’d get better results printing 1 or 2 at a time.

That white resin part looks a bit different though - those supports look bad from the start - and it seems like a smallish piece. There was another recent post about poor results with the white resin. I’ve almost run out of grey and just got a litre of white today - so I guess I’ll be finding out if how it prints soon…  Do get similar results for those ponies in grey?

I see what looks like little whiskers on the supports on the pictures of the white resin.  Do you see them on all your prints?  Looking at the gray prints, looking at the supports specifically, do they all start the wavy texture sway at the same height on all the models in different resins on different prints?

Thanks guys, these are all good theories.  Yes the tubes were all printed at once, I was thinking about weight but the accumulated peel of them all spread simultaneously across the whole build platform could certainly cause it to shift.

I have to admit I’m a little disappointed if I can’t print a hollow tube 3"x4". I need it mostly for small detail work but I don’t think that size should tax it to the point of failure.  The wall thickness is 1/8".  Sorry, can’t share the .STL since it is associated with my company.

Here are some shots of the assembled piece, heavily sanded and primed.  Bottom cap glued to center tube and separate top cap.

The white resin I’m not sure what to think yet.  I only did a couple of prints, went “Gah!” and put the grey back in.  I’ll do some more test prints.

Hi Bill,

The results you are seeing are definitely not normal, and it is something we will want to work with you to resolve. We saw your ticket come in, and you should expect a follow up later today.

  • Ford

Thanks for the follow up Ford, I’ve also sent you these new pics.

So I found a calibration .STL file that I thought I’d try printing this morning to see what I could see.    Everything about this file is known, sizes of elements can be used to see how your printer performs… it is square, the inner circle is a perfect circle.  On mine not so much.  The supports are pretty funky.  It also shows the surface texture well.

One was printed on the far left of the printer (hinge) the other on the opposite far right.  Grey setting @ .05

Thanks for posting Bill,

I think it’s important for the community to see what kinds of things can go wrong, and I’m not sure anyone’s posted failures like that before. That definitely looks like a return job - even the base layers are completely mis-aligned.

I hesitate to guess where the issue might lie. However - on the offchance, have you checked your build platform when it’s clamped on to the Z-axis bracket? is it locked tight, or can you get any rocking movement? My most recent printer came with a very loose build platform that was causing really dramatic failures.

Yeah, I’ve been following the message boards pretty closely to see what other issues other people are having and I came across Bracket posting.  My bracket is rock solid.  Actually I think the printer is slowly degrading, each print seem worse than the one before it.  At one point in time my base layers were square.

Oops,

I think I posted a close up of the same one twice… here is the other one.

Your prints are definitely getting a lot worse. Somehow I can’t see it being the laser - so I guess, that only leaves the galvos. I mean there’s really only a handful of key components that might be expected to fail - galvos, laser, stepper z, stepper peel, build platform, and resin tank carriage hinge and springs.

Well the upside is that to date - the Formlabs return process has been quibble free, fast and efficient - so hopefully you’ll get a replacement quickly.

On the other hand I just can’t see how they can maintain this return rate - I would have been on my 3rd printer inside 4 months  if I’d not repaired it myself, and I’ve heard from one guy who’s probably looking at his 5th printer. Which is why I want to gather as much information as possible about troubleshooting and maintenance.