I am trying to make some nozzles for a medical prototype. If I use a 0.5mm hole diameter for the nozzle outlet; it seems the Form 1+ makes a nice round hole when viewed under magnification. If I go down to 0.4 mm diameter hole; I have ~50% success at 0.1mm layer height. (interestingly at 0.05mm laver height I have no success.) Ideally, I could get down to a 0.3mm hole diameter, but I have no success at that no matter how thick or thin the hole is. I know formlabs lists 0.3mm as the minimum feature resolution. I’ve tried multiple orientations.
I was wondering, if maybe a thinner resin such as maker juice might be able to do it or is it purely a machine limitation. 1 benefit of the laser is it traces instead of being a pixel, so I would suspect it could do finer/smoother features then its spot size unlike a DLP printer. I know the Titan list an xy resolution of 0.05mm resolution limited to the pixel size of the projector. However, I’m sure the process of curing, resin viscosity, and peeling must affect those numbers. Anyways, I’m still impressed by the Form 1+.
For holes that need to be calibrated, the best method I’ve found is to print an approximate/undersized hole and drill it out to the diameter you want. The cured resin cuts easy with a twist drill. For smaller holes I use a pin vice, not power unless the hole is large.
Well when you are getting down to that size there is a fair amount of variability in how well focused the lasers are. If you see the discussions on the forums about the laser flare issues you will see the 300um feature size is probably a rather rough approximation as opposed to a real hard minimum that is guaranteed. I say this as any user with flare problems clearly has slop significantly greater than the 300um feature size would allow and it seems the primary cause for that was formlabs didn’t worry about precisely focusing the laser. With that in mind it would seem likely that the focus varies from good to awful, and that the smallest hole you can make is a function of where on that scale your particular laser lies.