More clever supports idea


#1

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.

PS : I am a structural engineer :slight_smile:


#2

Thanks for the suggestion! Support structures have come a ways since the Form 1 days, but they continue to be a main point of focus as we develop our ecosystem.


#3

Hi Oliver, after how many prints were you noticing this? I’m not a form 2 user yet, but I am trying to get an idea about this, and how rapidly this affect actually occurs.


#4

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.


#5

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.


#6

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 :sunglasses: :


#7

How many prints have you done on that tray, and so do those dots at the opacity they are now affect the laser penetration through the tray?


#8

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.


#9

Hi Frew,

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.


#10

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.


#11

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.


#12

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


#13

Even if you needed to keep the straight pillars on the supports it would be helpful to angle them 5 or 10 degrees from vertical. This would spread the wear a little and improve things.

I do agree that there are probably better ways to do the supports. I also realize that it’s easier said than done.


#14

Formlabs probably knows what the wear is like in one spot based on how many layers are printed in that spot


#15

We used Grasshopper for the parametric pens but Kangaroo is new to me. We have openings for Algorithms Engineers on our website :wink: Improving support structure generation to reduce material usage and improve cleanup is among our primary software based focuses and you’ll continue to see developments here. I’ve forwarded your ideas to our team.


#16

I’m a former structural engineer and the other SE is correct.

A spaceframe design for the supports will minimize wear on the tank and may lessen the impact of the cutting tool cutting support tips causing an abrupt force against the print.

Looking at the support design I’d be surprised if FL has SEs on staff.


#17

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.


#18

I can buy a whole lot of resin tanks and Form 2 before it adds up to the cost of one year of one Carbon machine. Hopefully the Resin Tank LT takes care of this issue though.


#19

Wow ! 2Ox the lifetime for just 1.5x the price, that makes it at least 13x cheaper.
Then it’s a no-brainer : the Resin tank LT is the new resin tank !

Any details as to what the lining is made of ? Or is there a lining at all ?


#20

Yeah, if it lives up to the marketing materials it should be an awesome improvement. No clue what they did to make it better.