I noticed that the resin vats are dotted with little dots after a while.
This clouding of the silicon layer is due to the vertical supports because the laser shines on the same area through all the height of the support.
So instead of doing vertical columns braces with diagonal struts, it would be more clever to use an angled 3D lattice.
Moreover, I think that the supports could be made more efficient by making it a real space frame instead of braced columns.
In short : less material, stiffer, and spreading the wear of the vat more evenly.
It is really hard to give specifics on how quickly that happens. It happens slower than you might think. I was printing multiple batches of the exact same part. The parts are only 3 inches tall and I was using Tough resin. After the first batch I could barely see the ghosting. After the fifth batch I could clearly see the ghosting. But there was very little noticeable difference in the quality of the parts printed in the 6 batch. I really had to look to see it. I could have moved the parts around the print bed a little between batches. I don’t expect I would have trouble until I am half way through a second cartridge of resin. Now that they are offering the new LT tanks I don’t expect it will be much of a problem going forward.
I see, I am really wondering about this because some parts I am looking to print seem they would really benefit from an orientation that would disregurard the need to tilt only to mitigate the ghosting affect. Especially where the object is almost self supporting, but when you tilt it you create a situation where it needs to be supported.
Hi Adin, the tilt is mostly to make more sections, hence sections with smaller areas which peel more easily from the vat’s silicon bed.
My thread discusses the issue of the supports which, for lack of a better generating algorithm, make braced vertical supports.
This means that the laser is going to strike the same small area again and again until it reaches the actual part.
Here’s the result, tell me if you can see the dots :
Hi Adin, the number of prints is not quite relevant, it’s the volume of the printed parts which counts.
That’s the volume of used-up resin, minus the losses in drips, and surface resin that ends up in the isopropyl baths.
This picture was taken after roughly 1.5 liters of resin, and I already had printing failures due to the clouding.
I managed to do more successful prints by using the corner areas though…
Back to the thread, there is an inspiring article on lattice structures here.
Have you heard or the Grasshopper plugin for Rhino, and the Kangaroo add-on ?
You might want to chek-out these videos.
It seems to me that the supports could benefit from a true form-finding algorithm with hard-wired basic structural optimization concepts.
I bet you would seldom end-up with strictly vertical supports.
Olivier , About how many milimeters of support cyclinder being printed in the exact same spot did it take to cloud thoes areas of the PDMS? I can sort of see from you pic the volume (length) of those main supports you are talking about looks like maybe 30 milimeters, So just curious how many prints of lets say a 30 mm cylinder printed in the exact same spot would give thoes results, you are showing.
Hi Adin, each point you see corresponds to a support of a little more than one mm in diameter and probably 10 to 15 cm in height.
Anyway, this whole vat degradation story is a complete bummer.
Newcomers in this field like Carbon have solved this issue and are likely to take over the Market if Formlabs doesn’t come up with a competing technology.
I was told by formlabs at 0.025 the trays will last about 1 cartridge perhaps longer depending on geometry. at 0.050 should be 2 to 3 cartridges… the higher the resolution the faster the fogging. also move pieces around on the platform to extend its lifespan
I would imagine that they would rather have more effort working on the primary solution to the problem, like the new longer lasting resin tanks and other solutions. at some point a perfect support structure is going to be irrelevant.