Dimensional accuracy between black V2 / V3 and grey V3

Hello all,

We have been primarily using the Form 2 for the past few months to print 2 to 5 part moulds with much success.

I’ve just printed for the first time V3 black. And in a part that has always been successful in V2, has cracked - during printing - at a point where there is a relatively large feature. I’ve read in a few posts that people are finding the V3 is cracking more so. I think it may be a shrinkage issue with the resin, and that an update to the print settings may be necessary. I’m also finding that the edges of the V3 black produce a sort of ‘coping’ effect, that hasn’t been nearly as prominent in the V2.

Dimensionally the V3 resin seems superior to the V2. The mating surfaces of the moulds seem to interface more accurately which is observable just by the naked eye. However after this (shrinkage induced?) cracking I’m worried about printing further with it because these parts that we produce are taking up between 20 and 30 percent of the resin cartridge each print - the cost adds up!

Can someone please tell me, objectively, the advantages of V3 over V2 and point me in the direction of a datasheet? After a trawling of the posts all I see is ‘including having a matte finish, it offers numerous advantages’, but having a matte finish is not an objective advantage!

Also does anyone know in which order of dimensional accuracy the resin collection is? My understanding is that dental model resin is at the top, then is it grey v3? or black v3?

Thanks so much for reading over.

Hello,
I’m not sure about black V2/3 but for your last question I believe the order is dental>grey>black. The grey resin was recommended for making dental models before the dental model resin came out so I’m guessing it takes the #2 place now. It was also the resin that came with our Form 2 for our dental lab. But maybe someone can confirm/deny this with some data. :smiley:

Black V3 does require denser support structures than earlier versions of the resin because of the matting agent. If you have parts that were previously being printed in Black V2, it’s important to clear and re-generate the supports using Black V3 settings.

One of the main causes of cracking we’re seeing is when two separate islands mate together. If you visualize a carrot character like this ‘^’, the boundary at which the two seperate halves meet requires additional support structures. We’re looking into making the support generation algorithm more robust to catch cases like this. In the mean time, manually adding additional supports in these regions can be a big help.

The main advantage with Black V3 is enhanced feature resolution and for many, the Matte finish is an aesthetic advantage that makes parts more appealing and presentation ready. We’re seeing most cracking caused by under supported geometry or interfaces between disconnected islands rather than shrinkage or warping of the final parts. Let me know if any of these modifications are applicable to your case and help to cut down on cracking! I’m happy to take a look at your .form file as well and offer any tips.

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Thanks for that info. I suspected as much! I think once we freeze the prototyping phase we’ll start building the moulds in dental model :slight_smile:

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Hey Frew, thanks for the response. I’m going to pay extra attention from now on where the parts bridge together - and support them like a responsible parent.

I used about 6 liters of V2 Black with the Form 2 and many liters with the Form 1+. I don’t like the V3 Black! The matte finish is not more pleasing. I think it looks like there was a print error and it wasn’t cured good. I like that shiny finish. It also seems like it is less durable and more flimsy that the black. Oh and it cracks for no reason.

When I finish this last liter of black, I’m going to all grey on both my Form 2’s and the Form 1+.

Also, Frew was this based on surveyed information? As far as I can see on the forums, people aren’t exactly happy with the matte finish. It almost seems like a marketing ploy to be able to add a percentage of something like calcium carbonate to shave a few percent off the production cost. Have I said too much?

P.S. I feel like the feature sharpness is almost amplified in a fake way to produce this coping effect on the edges.

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