Yes it's so true what your saying about low volume custom products being very expensive. Of course I don't know what they payed for the design and if any patents, international or other wize came with it. Harbor Branch is claiming a patent of some sort on a ring thruster. I finally found some basic data about there thruster.
http://www.hboi.edu/eng/rov_comp.html
Also corporations love to spend money on R&D and with allot of the different parts on this thruster being injection molded that can run you $30,000 to $50,000 per part for the T1 Steel molds not to mention the cost of all the tech guys designing and testing the critter at $30 to $80 an hour.
How about I just make my sub and ring thrusters out of snow. I've got plenty of it to spare at the moment. :)' Ice burgs flood right.
So if I understand you correctly, if the PSUBers of the world start hording millions of ring thrusters we can get a better price.
Mark if you find and thing more later on, please send it to me.
Brent Hartwig
Amateurs built the Ark.
Professionals built the Titanic.
From: "Mark Roberts - Harbortronics" <Mark@Harbortronics.com>
Reply-To: personal_submersibles@psubs.org
To: <personal_submersibles@psubs.org>
Subject: Re: [PSUBS-MAILIST] Ring Thruster Data
Date: Sun, 7 Jan 2007 18:37:01 -0800
>Just from looking at the structure, my guess is confirmed by your
>description, that it's a brushless motor design, with the permanent
>magnet rotor attached to the blades. It looks like an awfully simple
>design to be worth $1M! I've seen motors with this sort of shape
>marketed, but I couldn't find any examples just now.
>
>BTW, the reason all this U/W stuff is so expensive isn't so much the
>difficulty, it's due to the market being so very limited. If you
>make 100K units of something, you can amortize a $1M development
>cost over each unit at $10 each... not a big hit. If you only make
>100 units (much more realistic!) then your cost is $10K per unit,
>before you've even made the part!
>
>Mark Roberts
>Chief Engineer
>Harbortronics LLC
>Mark@Harbortronics.com
>253-858-7769 (Ph)
>253-858-9517 (Fax)
>www.Harbortronics.com
>