Optical test results: Do I need to change LPU?

After sending images to my reseller, he told me that Formlabs has recommended an LPU change due to contamination (I have never had a resin leakage though, maybe dirt?). I was quoted $1.4k for an LPU and $250 service fee to change the LPU. I just wanted to make sure if that’s the exact cause of the flaws on my prints because my latest prints did not fail, it just had a line protruding.

I have greased my x-axis rod, wiped the bottom of my tank, and removed the LPU roller cover to clean both the glass and the rollers before printing the optical tests.

Here are my optical test results. It was hard to clean the prints with it still on the bed so there were still resin residues present. I have since removed them and submerged them in IPA for a bit.







Things I noted:

  • Most of the thinnest lines (both vertical and horizontal) are merged together.
  • For BR, BL, the 2nd thinnest horizontal line are merged together.
  • For CC, it seems to be the ‘dirtiest’ and not smooth as the others.
  • The tiniest pole broke off for BR during washing
  • Additional line across BL and BR might be from dirt on bottom of resin tank

Are the prints that bad that it warrants a change in LPU? Should I try other things like greasing the z-axis rod (was previously told not to but now okay if I made sure not to overgrease), trying a new resin tank and print the optical test again to see if that helps?

Thanks for your insights.

Hi zedabyu,

That is great documentation! At a glance, that optics test looks pretty good - the line protruding and some of the lines merging together could be related to the LPU itself. My suggestion is to pass along the updated logs after that print as having the logs to compare before and after the cleaning/test print to get additional insight from the team.