Failed prints: Crooked built platform?

FACTS:

  • printer: Form 1+

  • Software: PreForm 2.0.0 (= latest)

  • History: bought in september (+2 months old) / 50+ succesfull prints

DESCRIPTION OF THE PROBLEM:

  • Incomplete printing of parts with more than 1000 layers.

  • slight flaking on surfaces.

  • solidified resin on resintank bottom after print has failed

ELIMINATION OF CAUSE:

  • The problem is NOT related to bad or worn out resin tanks: five new tanks have been
    purchased and tested, resulting in more failed prints.

  • The problem is NOT related to the resin: tested with fresh resins: black, clear,
    white, grey, though and flexible. No differences in changing resins.

  • The problem is NOT related to the laser and or mirror: I have cleaned the main
    mirror - following the instructions - prior to a laser-spot test. Images taken with three different camera’s , and
    i can not find bunny ears or a carrot.
    (Note that I have not touched nor cleaned the galvo mirror. Formlabs explicitly states: “Do not do any additional cleaning without consulting Customer Support.”)

  • The problem is NOT related to the printjob: I have passed a point where previous successful
    prints don’t work anymore. In fact: even non-complex and small objects are
    doomed to have a certain fail rate.

  • The problem is NOT related to the PreForm version: failed prints started occurring when
    using an “outdated” version. Upgrading to 2.0.0 did not solve anything.
    Reverting to the version I had made no difference either.

  • The problem is NOT related to the built platform: a new one has been purchased and
    tested: no difference. The one that has been used for over a month has had a little
    service on the quick clamp latch to asure a firm lock on the Z-axis bracket.

  • The printer is POSSIBLY NOT related to faulty calibration. The bases strongly stick
    to the built platform, supports are being printed nicely and firm, there is no
    shifting, stretching or offset. Ofcourse this statement is only true for the
    places where the ‘inocmplete printing’ is not taking place.

LATEST OBSERVATION:

  • During some of my latest trials, I heard an unusual sound during the peel action.
    Taking a closer look, I noticed that the built platform is being pulled down
    when peeling, upon a moment where forces rise to high and the print releases
    from the silicone layer, allowing the built platform to spring back to its
    original - and parallel - position. Hence: the strange sound. (Obviously, this
    phenomena gets more pronounced when printing larger cross sections.)

A BOLD ASSUMPTION:

  • I think that the cause to my problem is a “worn out” slide on the z-axis. The
    elimination of all the obvious parameters tells me that the problem has
    suddenly raised, and is without doubt directly caused by the printer it selves.
    Sadly I have no reference of how a brand new Form 1+ printer behaves. How
    wobbly is the built platform? When attached and tightened with the lever, there
    is still some play when I manipulate it gently.
  • Another cause could be that there is no change in mechanical rigidity, but a change in
    the amount of adherence of the print. What could this mean?

TAKEN ACTIONS:

  • Performed the Formlabs test print. Surprisingly: this comes out succesful. I asume it has to few layers for the problem to have a dramatic impact.

  • Searched the web to find similar complaints. Upon today I have not figured out which
    keywords might render usefull hits. I have read allot about failing prints, but
    I’m not finding anything about wobbly built platforms.

Please help me to pinpoint the cause or share similar experiences.

Its more than likely do to your print… what are you trying to print? If it is having issues removing from the PDMS layer it could be that your cross section is too much for the z motor to handle…

On a side note your laser spot check does not look the greatest in my opinion but it could be fine for others if my laser test looked like that I would clean all mirrors.

Thomas,

Here you can see a screenshot of a printjob. First attemt in printing this a month ago was succesful. Since I need alot of them, I re-oriented the parts EVERY time I launched the job again. (to make sure I distribute the stress on my tanks). It all worked out great untill a certain point. Re-printing a previous sucesful file now fails.

So therefore I can conclude that it is proven that the file(s) I sent to the printer are “okay”, but another parameter has changed during time.

This is a litle more complex part that I tried. It’s quite big and consumes pretty much resin. A refil has been done during testing.

The results: (i marked the edges)
First print

Second print

I did two other prints with completely different orientation, but no change.

Bellow is a screenshot of the previous version of the model: (slightly less complex geometry)
The first time I printed this one, it came out completely and smooth.
When I try to re-print this one today, it fails and prints incompletely.

Another print that has worked in the past but fails today:
This one has less than 700 layers. I would not realy consider it to have complex geometry or high stress cross sections.
Correct me if i’m wrong please.

Before you look for zebras, look for horses.

Call support and get the instructions for cleaning the galvos.

When I get sudden failures like yours, it’s always cured by giving all mirrors, the big one, the small 45 degree internal mirror and the two galvos a righteous cleaning. To do it right takes me about an hour. And magically, happiness follows.

Looking at the last image of your laser it looks like there’s a spot on there–it’s very likely that there is a spot of dust on one of your galvo mirrors, get the OK from customer service to go ahead and open it up and clean them

It’s probably worth noting that the Form 2 has an enclosed optical path, rather than the open bay in the Form 1 and 1+. The new design will keep dust out, and in the promo material they make a point of the improved engineering.

“And the number one enemy in optics is dust. To test the Form 2’s dust resistance, we placed a printer in a sealed chamber and blasted it with talcum powder for six straight hours. At the end of that ordeal, the Form 2 still printed at full performance. Technically, this means you could use a Form 2 in the Sahara desert, if you manage to find a power outlet”

Printer hygiene counts! Now, before I do a large or complex print, I spend the time to clean mirrors. Don’t like the job, but it pays off.

There’s a screw on top you can tighten a tiny bit (like 5degrees) at a time and test on each tweak, to improve it’s clamping pressure. It should not move when clamped.

But by the look of the prints, it’s what @Rob_Steinberg said. I keep a plastic kitchen-size garbage bag over mine at all times - even when printing, and it’s really helped with managing dust.

Okay, thanks for the comments.

I will submit a ticket and see how cleaning my galvo mirrors helps.

In the meanwhile I have made a short video that clearly shows how my built platform gets pulled down by the peeling:

I have also found another topic about the pop noise.

…and you took that video after tigtening the platform? What’s not clear from the video, is what exactly is moving.

  • does the platform rock on the arm?
  • does the entire arm (and jackscrew) move with it?
  • is the tower moving?

You’ll need to narrow that down.

Christopher,

I know my video sucks… Hence the lines to make it a little bit more clear what exactly is moving.
What you see here is a new built platform which has been tightened and verified. (the clamping system does not need any adjustment, connection to the arm is as firm as it can get)

Whenever I run a new print that makes the popping sound, I will take effort in making better footage and see if i can verify what exactly is moving.

The strange thing is that I read feedback that describes the popping sound as “normal behavior” and is caused by to much stress due to large cross sections. (meaning that the model and/or .form file needs optimisation)
This is in contradiction with the fact that I have succesfully printed stuff in the past withouth this fenomena, and now - withouth change of the print-job - it is there and causing the same print jobs to fail.

What I will do first though is clean ALL the mirrors. I got a ticket submitted by now and Formlabs gave the go ahead to advance with the galvo mirrors. Just to narrow things down.

From the view in your last video, there’s significant platform movement in the peel process. I haven’t seen or experienced horizontal rocking of this magnitude. When the resin tank comes back to print ready, there’s severe out-of-alignment between the build platform and the resin tank, they must be parallel for successful printing.

I have replaced the peel stepper motor many times, and the dual arc’d arms guiding the resin tank frame throughout the peel process create a popping sound when those arms click into their resting place when returning to the print ready state and also when leaving the print ready state. The popping sound intensity will increase and decrease depending on their degree of alignment. These arms are adjusted by physically bending them, not the most elegant method, but is the only way to adjust them. If the arms are indeed in alignment, to reduce the popping sound’s intensity some heavy-sticky bearing lubricant can be used where the arms click-into-place on either side of the peel motor. I don’t recommend doing this unless you are very familiar and skilled with general maintenance of machines.

Hope this helps you.

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