(Relatively) Large Prints Failing - Need Advice

Hey all,

A friend (who will be joining this post, shortly) is very graciously letting me print a project on her Form 1. Unfortunately we’re having some issues. The part in question (4.57 x 3.11 x 3.38 inches) is one of a number of components that will come together to form a larger piece. I had hoped that by keeping the build volume lower than the Form 1’s max build volume that I would be safe. That was not to be the case.

The 1st print didn’t even take hold of the platform and was a wash all-together. We cleaned the platform and reoriented the model in PreForm and started again. This print started and got about halfway through and failed as well.

The model was built and exported from Zbrush, is hollow with 4mm walls and is a total volume (supports included) of 208.2ml. The target print resolution has been 0.05 with grey resin.

I moved through the slices and think that MAYBE I see a spot (see screen-shot below) that might have needed support (boy, how does one know?!) While my friend is experienced with the Form 1, this is my first foray with the printer. My prior experiences have been with FDM machines and smaller models, for that matter.

Were I a bit smarter, I would have started with something a little smaller. However, this project really got stuck in my head and demanded completion. :slight_smile: I am absolutely infatuated with the printer and really hope to get this project run through it.

Any help, advice, life lessons, etc. would be very much appreciated!

-Lee

I’m the owner of the Form1 in this case. Lee’s been excellent to work with, and thought this project is a bit of a challenge- I think it would be a great experiment in testing out the limits of the Form1’s macro capabilities. I’ve found my printer to be pretty dependable with some of the larger prints I’ve done (And I’ve only done a handful, I mostly work on miniatures) but these pieces are proving a bit of a problem and I hate wasting Lee’s resin.

Some info on the printer- I’ve done some recent test prints, and it seems to be pretty dependable with detail work and there doesn’t appear to be any spotty areas across the print bed (despite an airbubble that’s appeared under the PDMS layer. Its presence hasn’t correlated to any issues in the test prints I’ve done.) I’m wondering if there were too few supports for this print, but I find it odd how it failed across the entire circumference (and rather catastrophically, at that!) I’ve had large hollow pieces fail before, and when they did the damage cascaded rather than ending abruptly across the entire piece.

Curious! Looking forward to your collective insight.

Hi Sarah and Lee. :slight_smile: Are you saying it fell off because of a weight issue?  …and it happens later in the print? Yes, you could try more supports and in better spots … before you try that …

Did you try coating the build platform with a very thin coat of resin and sticking it outside to cure for some minutes? I’ve found this provides a better foundation for the initial layer, since it covers the entire surface area of the build plate … it might be harder to get off the platform, but on another resin based machine it seemed to be worth the effort. Maybe I’m imaging things … worth a shot maybe, in conjunction with the support mechanism advise you will get.

You could also try smaller pieces. I have a licensed copy of netfabb, and I can chop it up into smaller bits, if that’s not what you did, originally, and you don’t mind where the reassembly occurs in the model. You can easily mend the pieces with a laser pointer though.

On a related note, it would be fantastic to control the “raft”/foundation creation inside of both Preform and other 3-D printing software … this is actually a problem for some models I do in FDM, where it would be useful to be able to control the way the 1st “raft” is constructed for mechanical parts.

Also, Sara and Lee … I do have some PDMS, so we could reapply a new layer if you wanted to … having a second tank is not such a bad idea, if you plan on doing this thought … print with one tank, and have a secondary for cleaning and reapplication. The time invested into doing a new PDMS layer probably equates to the just paying to get a new tank from Form.

-sj

Based on your pictures, I would stop using up resin and open a support ticket.  I have attached a picture from a print with a known bad laser.  The skin tag looking bits hanging off are not good.  Let FL support help troubleshoot this.  I hope I am incorrect but a support ticket is a good place to start troubleshooting this.

On a second read and viewing of pics, this doesn’t sound like the adhesion problem I first thought it was … couldn’t tell if the piece had fallen off the plate and you just photographed it on the plate (most likely, not). Not sure what this is, but David sounds like he has experienced something similar with his bot, and a build with what looks like a lot of curvature.

Typically when I have a catastrophic print failure on a large build with various machines, I try it small scale it down to a smaller size, and see if it exhibits the same behavior and results in the same issue(s). Less material waste and you can (sometimes) catch where it fails … in this case, on this bot … not so much, unless you mount a micro camera underneath the bot in a safe location out of laser path volume … and print with clear resin …

I presume this is the auto orientation that PreForm suggested to print with. When opening the ticket, I would suggest submitting multiple angles of the failed build, including a top perspective coupled with the PreForm layer snapshot at around the point of failure, so they can see exactly what the laser was doing at that stage.

If it were me, I’d reprint at smaller scale and maybe a reorientation, more supports, while either watching it, or setting up a micro camera to help diagnosis … or of course, you could always stop printing and just wait for the ticket response and get feedback from the FL team who may say “yes, we have seen this, here is the solution”, or “send us more info so we can help you”, etc.

-sj

Addendum: 1. If you can negate the bad laser hypothesis with FL, you could always add in custom support structure directly into the model to help the build succeed. 2. Being able to add/modify custom support mechanism would be a welcome (advanced) feature in PreForm as discussed elsewhere.

Unfortunately, I have extensive knowledge in fail lasers and the different ways it can present itself.  In this case, scaling down may only mask the issue.  The skin tags is one of the tell tale signs of a failing laser.  FL has a name for them but I can not remember what it is and I do not feel like searching for it.  I can not say for sure your laser is bad as only FL can make that diagnosis and I hope I am incorrect.  One of these days, I am going to put together a symptoms list with pictures together.  I was hoping FL would do this but I can see why they have not.

As I said above, I would open a support ticket and wait on printing anything else until they assist you.

Let us know how you make out.

David

Thank you Scott and David for your replies.

I’ve been nailed by a bad cold and have spent today on the couch. When I have my wits about me, I’ll post right away.