Payload Interface: Mechanical (Trident Kickstarter Update #10)


Ha, thank for saying it d.underwater. I appreciate your interest and I am glad to help.

I actually wanted to post photos with a set of verniers showing accurate dimensions however I need a new battery for my verniers…in the mean time my trusty old tape measure will have to do. From a design point of view I am expecting to use every micrometer of wall thickness to get these modules back from 100m. For example, 100m depth x 1026kg/m^3 density of water x 9.81m/s^2 gravity = a whole lot of pressure = a massive force on the hull panels!!

Stay tuned for actual dimensions when I get my new battery.



Does anyone know how to convert a raster image or a .pdf line diagram into a 2D vector model and in turn into a 3D model for analysis?

I am beginning to think my simply supported beam calculations in x and y are just not going to cut it…



try fusion 360. I’m working on some payload bays and modelling using it - hope to have some stuff soon.



Read this one while watching the Test in Adelaide where I live.

A few thoughts come to mind the good ones click the bad ones you just laugh at and throw in the bin

Glad to see someone else doing the R&D this time I spent a fortune in the mid 1970s developing and reefing the motorised shark cage which now sits in the National Maritime Museum in Sydney saved my life and made abalone diving safer

· The polystyrene foam boxes provide a lid and base of large size

· They are discarded once fish delivered interstate so no cost

· Glued together they are thickened to useable sized blocks

· Easily marked and shaped and cut with sawing knife to make models

· The foam has strength as well as being near weightless

· The buoyancy tanks of aluminium on the cages we put an air inlet in from memory and pumped some compressed air to withstand outside pressure

· We made the aluminium buoyancy tanks able to slide forward to readjust positioning

· Two small aluminium tubes underneath become the adaptable primary attachment base to slide any different add ons into

· The add ons can be released by reversing machine. They slide out. If positive buoyant they go to the surface as well Etc etc

· A coiled line released will unravel and mark position on surface etc etc




I’m sure I can do this manually in AutoCAD. I do it routinely. If you wish I will do it for you. Email the file to I’ll do it at lunch tomorrow.



Thanks dbihary,

I appreciate your interest and offer of assistance. I have forwarded the files by email as requested. Here are the approximate hull shell dimensions for everyone else (thankfully my verniers are now back on the job).

profile_dimensions.PDF (158.3 KB)



Thanks Jesse,

Awesome, I think Fusion 360 is installed at the state library!

It seems I now have another thing to learn.



Hi there.
I don’t know if you work on a Mac, if you do there’s a fantastic application called Super Vectoriser which converts raster to vector very well.
I also use Fusion 360, it is also a brilliant application, although I am a bit worried that, because it is cloud based they will cut out the free version when they have a large enough user base. It is quite different to a lot of other CAD programs (I find it very intuitive) so the learning curve can’t easily be transferred. My other favourite would be Rhino, very good for converting 2D into organic 3D shapes, but I don’t think there’s a free version.
Good luck.



Hi Brian
Reference is made to discussion back in December 2016 between you and Jason on releasing parts and CAD file for the Trident hull and recent discussion on payload interface last few days of November and first few days of December 2017 .
Do you have available surplus Trident hull of “current shape and geometry” that have been rejected by QA/production department for Jason and other guys for prototyping work for “new” equipment & assessories?
The CAD file for the Trident hull should also be available now as you have started production of the Trident Beta.

Quote from most recent communication from Jason (Australia):

“Oh and yes, a real Trident hull would be great to have and to hold as a jig for testing and adjustment purposes. Boy oh boy, how amazing would that be. You just pushed my excitement levels off the charts. In the mean time however, as an alternative, I have been led to believe a hull model might (hopefully) be released in the not too distant future”.

Looking forward to be hearing from you soon!



Thanks Andrew,

I appreciate your interest and assistance.

I am currently constrained to Windows so Fusion 360 is my new point of focus. I am sure Mac has some of the answers to many of my frustrated questions however I work in a PC environment…for the moment.



Is jason.jenkins21 and pforperry the same person?



Ha, no we are not.

Pure coincidence.



With great thanks to dbihary, here is a digital version of the large shells sitting on my sideboard at home.

With access to the CAD model that dbihary has also created I will now dive into the digital world to see how these extruded aluminium sections respond to pressure.



And here is a sketch of how I propose to seal the [highly stressed incredibly difficult to seal non-round] end plates.

proposed_endPlate_seals.pdf (43.9 KB)

With careful dimensioning and assembly, all forces are resisted by end bearing between the aluminium plate sections. The poly sulfide sealant becomes a cast-insitu o-ring that can be removed to service the internal components if ever required (notwithstanding my proposal to pot the battery compartment as a way of supporting the outer shell).



Boy, that perimeter groove really calls out for a large O-ring, if I may
suggest. Polysulfide and other caulks have a risk of a gap leading to



Thanks mdm, I appreciate your interest and advice.

Yes, as Elon seems to say quite a lot…this might not work! You may have noted the presence of leak detectors in my order from Blue Robotics…and I will be fabricating more than one…I will say no more.

To increase the chances of success, I will be keeping the gaps as small as possible as a way of minimising strain in the gasket (hence my proposal to use poly sulfide instead of polyurethane, which on paper requires a larger bond thickness IVO 5mm). Since the joints will compress under load, the poly sulfide will be compressed into the small triangular section (I hope) to create an effective seal without blowing out.

An o-ring would be great however I am concerned about the square corners and my (in)ability to fabricate clean cut ends.



Hi pforperry
How are you doing with your project of making prototypes (Wings) for extra space and payload to the Trident?
I see the first Beta Trident has arrived near Sydney Australia, so if you are not too far away a visit could be usefull.



G’day Kaare and happy new year.
Progress on the prototypes has been very slow because I have just returned from my Fiji and New Zealand trip…another amazing experience…and I am getting ready to return to a busy year at work.
I have since fabricated (or received delivery of) most of the tooling and components including the battery packs, chargers and resin/microspheres for the syntactic foam. The last components to finish are the doubler plates and internal bulkheads for the pressure compartments. With this in mind I am nearly ready to assemble the first pair of modules (they sit ever so temptingly on my sideboard) to be used for COB and COG testing and adjustments and ultimately for the first round of pressure tests. I am beginning to understand the complexity of working between theory and practice!
I also note with keen interest the presence of a beta unit in Sydney…I hope to get involved in one of the expeditions later this month.

Kind regardsJason



Any news on your project?



G’day Kaare,

Unfortunately not…I cannot believe a whole year has passed. I am away at the moment but return at the end of the month. I am really struggling to find time away from work and other commitments.

On the bright side the delay has worked in my favour a bit since I can now tinker with the benefit of experience and familiarity using Trident. These modules are still very close to the top of my list of things to do.