So: for future readers : Covid got in the way, but having now returned much much later: I tried adjusting z by -1mm as suggested on the printer : and… two prints completely failed.
I’ve just contacted formlabs support out of some frustration, so will report back (if!!) i finally fix this, having gone through all of their (online) suggested stages for fixing non support.
Well - experimenting with different z didn’t fix anything.
I reached out to formlabs support who have been really helpful by email (why didn’t i don this before? Doh !?) sending me esp. some standard pdf briefing documents about initially cleaning the optics, so we can see what happens from there. Erika diagnosed from photos I sent that the optics look dirty (mostly dust) and explained the optics should be cleaned every 6 months or so. (Which I haven’t), so seems a good start. Much reading later I realise the optics need to be kept hyper clean, cleaner than one might expect … and the cleanliness deteriorates just sitting around through dust settling out from the atmosphere. Having done that I’m expecting to print some (standard) optics test diagnosis models for them to look at. (Assuming they stick to the build plate of course!)!
Will report back …
Well that was interesting !
I cleaned the optics, (glass galvo mirrors main mirror and the end of the laser tube) with pec pads and ipa - and learnt doing it slowwwwwwwlllly prevents marks appearing from where the iPa is evaporating behind the pec pad.
Never come across this before with camera lenses so it’s a new thing to have learnt .
The optics test print printed perfectly (as confirmed by formlabs support from my photos) so I’m feeling elated my printer appears to be in tip top condition.
I printed my model in the grey v4 resin - it printed beautifully (so my model is ok) , then turned back to the tough 1500.
It failed …
I noticed the resin had become very viscous - to the extent that during heating I got an error that the wiper was jammed … which stopped happening once it was warmer, but in comparison the resin is like treacle compared to the grey v4 resin (I used for the optics print), so I wonder if it’s viscosity is causing partial prints to be sucked off the print bed just by viscosity - it’s like quick sand when the bed moves.
So I hit on the idea the viscosity has gone up so I’d try diluting it with some dpm solvent (which I use for cleaning parts) in the tray - and match the viscosity to that fit he grey v4. After all I’ve lost nothing if the resin is now junk
I find that with manual use the wiper reveals The bottom of the tray - it appears clear before the resin runs back - which it never did before.
Felt I was on a winning streak but …… nah. The print half way through looks as though it has failed with “stumps” attached to the build platform.
Some googling i see that resins are at the start of their life different viscocities anyway - so maybe i went too far - or the thing I’m beginning to realise - the resin is shot. Which is irritating as it has lasted under 18 months so the advertised life expectancy is for me - not achievable.
I think however I might experiment with open mode and see if I can coax something out of it before binning it
Which ironically will require me curing it anyway !!
Will report back ….