Small Needle Features not printing


I am working on a project where we need an array of small needles, about 1.2mm tall, 0.5mm diameter. I have verified that the printer can decently print this feature:

However, I am encountering a problem when I try to print the needles on the mold I have created:

(Yes it is different resin, I had the same issue with Black resin)

I verified that my STL model is using high resolution. I can’t figure out why the needles aren’t printing as part of this mold.

Here is a previous version of the mold, where the needles are shorter (0.7mm) and there are walls on the print (which I was worried about creating “cups” with):

They’re not very clean, but at least they printed, unlike now.

Any Ideas? Here is the Preform setup:

Have you ever cleaned the optics on your printer? Fine details start to degrade first, before larger more obvious defects start to show up…

You have a rim around the area with the pins. This may cause some cupping effects. It may be better to print the pins separately as inserts into the main body of the print.

I actually just access to this printer. The lab owner purchased it refurbished about a year ago, and I doubt the optics have been cleaned. Is that something that would become an issue within the span of a year?

Thanks for the advice, I was considering this but didn’t want to do it because of laziness. I think I’ll give it a shot though, as I’ve wasted too much resin with dud prints.

The optics can get dirty quickly or slowly, it all depends on the conditions they experience.

Dusty room? People smudging the optics with greasy fingers? etc, all these things can cause problems. Formlabs has a webpage on cleaning the optics.

I printed a similar MNA patch master last week in clear resin. Turned out perfect.
Maybe you could try printing at an angle?

Also, as suggested you should check your optics for contamination.

Here’s that Window cleaning guide!

Those look great, what are your needle dimensions?

I’ll give optic cleaning a whirl

Needle length : 1 mm
Base Diameter : 0.45mm
Tip : 0.075mm