Claudio, I’m not sure what you mean … I don’t really think I’m mixing up too many things, I was trying to answering some of your concerns about the 3D hull.
As for what to change to improve a IOM, I definitely don’t have any advice for Brad, or better Brad doesn’t need my advice (it’s the other way around actually) he seems more than capable of doing it by himself, and quite successfully I may add:
http://smys.yolasite.com/resources/SMYSNLDEC07.pdf pages 11-2
Gio,
my first post/remark to Bill was referred to the 60mm draft, nothing else.
Then came up the name of Brad and my comment was simply recalling his talent as designer and skipper including Sail making.
I have nothing to adds !
Yesterday, Selwyn took Sabre up to Kogorah for a regatta.
He said, “Mate it was amazing. All the fast IOM guys in Sydney were there plus three from our club. Multiple national title holder (8th in the recent worlds). 12 boats, variable conditions.” Sabre took two firsts and one second of seven races.
Here is a link to a video from one of Selwyn’s club races https://www.youtube.com/watch?v=fd1oC4CxESM.
The pink boat is a Britpop sailed by Lynn Kreibig and the green 167 is Selwyn.
As a complete non-racer (non anything really) I thoroughly enjoy the banter with my popcorn - One also learns quite a bit 
Are you designing hulls with 3d printers in mind, or is it more a case of Selwyn finding the settings that work for “traditionally” designed hulls?
I think what I’m trying to ask is - have you changed your design ideas based on feedback from Selwyn? Adapting designs that make the 3d printed boat better that wouldn’t necessarily make sense with a normal layup?
I have adapted my designs to print better, though not below the waterline. 3D printers don’t like flat surfaces…I guess the combination of heat, thin wall, and flat surface often results in a wavy, rather than flat result. So I’ve modified my designs to have more curved surfaces and deck recesses, etc. to improve the printed result.
We continue to learn and tweak, both design and process. Beta Sabre is printing now, so stay tuned.
Ok, I see what you mean about the thin deck getting wavy. Isn’t it odd that it doesn’t do that on curved faces. Any idea what on earth the explanation is? I know that on a curve you get more material on the inside than on the outside, maybe that helps hold the shape on these thin walls?
You’d be better to ask Selwyn that one. I do know that he has just started testing a cold printing process that he feels excited about. He seems to think it helps with the waving and that the finish may even be better. Too soon to know for sure, though.