Re-Opened: All prints fail after a certain time/height

[Ian_Walton]

Hi All,

I started this thread several weeks ago but due to work commitments couldn’t follow up on progress until now. Re-igniting the thread following some tests. Big thanks to @DavidRosenfeld for your help. Also thanks to @KevinHolmes - I have replaced my large mirror with help from your resources. Works great.

This was the original thread All prints fail after a certain time/height

To cut a long story short I am an experienced Form 1+ user and keep my machine very clean at all times, including vats and resin. I have replaced the large mirror and cleaned galvo mirrors as and when needed.

Despite this all of my prints drastically fail at a certain height almost as if cut off suddenly, and quality is poor to terrible with flakes everywhere.

I have now conducted a flare test and taken some pictures of my most recent spectacular fail. To my eye it looks like my laser is ok - no major flare, a very faint square outline when the cover is open.

Laser Spot Tests:

Cover Closed

Cover Open

Example of Failed Part:

So it seems to me I have a reasonably good laser, a clean machine, new mirrors and catastrophic fails!

Any suggestions as to what could be causing this would be greatly appreciated. @DavidRosenfeld I still need to check for issues with the travel of the build platform along the screw thread - this is on my list.

Thanks everyone,

Ian

[DavidRosenfeld]

Ian,

I think the laser spot can look more defined. I would be sure all the mirrors are really clean. It should look more like a bulls eye with a small amount of flare. If I am not feeling lazy or get side tracked, I will take a picture of what my laser spot looks like tonight. Looking into your part, you have supports that aren’t generating way before the round failure point. It looks like something in your Z axis is shifting at the shift in your part. I would measure how high that is off the platform. Then measure off the vat (obviously be careful not to stab your PDMS layer) then with the machine off, you should be able to lower your build platform to that height to start figuring out if you can feel anything strange in the Z movement.

I do not remember if you had opened a support ticket yet, If not, this would be a good time to bring support into the conversation.

-David