Very thorough test analysis Seagull.
Back in the early days, I say “early” as in receiving my printer from the Kickstarter campaign, August 2013…my first print was very tiny magnifier adapters for my shop eyeglasses. I posted my experience here Hi Folks, successful prints of small parts . I was very happy with my new printer until my first print failure, in clear there was a string of bubble type anomalies. It happened mostly after changing resin color, when gray was added, so after printing in gray and then changing to clear. Before starting a new print in clear I noticed a small drop of resin on the build platform, it was a gray resin droplet…how could this be, I’m meticulous when cleaning between print-jobs, clean twice print once. Wiped the platform once again, got distracted and came back 30 mins later to find another droplet. Sure enough the platform is mostly hollow and somehow resin is entering the platform when printing.
I tightened the screw close to the leak and voila, problem solved. But I then thought I may have created another problem, the platform being misaligned in the z. Used my $100.00 straight edge(.0005in over 12 inch tolerance) and found the platform to be horribly mountainous with valleys and peaks…I say horribly because a $100.00 straight edge will show every little change in flatness.
I then proceeded to adjust the fasteners directly attached to the aluminum plate to less than .025mm difference over a two inch area and .033mm over the entire span of the aluminum plate. I figured this would do until a better plan came to mind.
That was 1.5 years ago and I’m still using the original build platform today. I check for flatness often, but have not had to make further adjustments since. I have perfect prints 98% of the time, and when there is a failure it’s because of shortcuts to cleaning properly between jobs.
I have yet to spark-up a Tough resin print, I’m rebuilding a post-cure station with more powerful UV components.
You have definitely identified an important factor here Seagull. I’ve been designing a platform to reduce these issues, but time is at a premium these days for me…not sure when I will produce a new set-and-forget platform.
cheers,
Brent