[PSUBS-MAILIST] Working on a new DBP design.

[Soren Kristensen <soren@soekris.com>]

Hi Everybody,

I'm new to the list, but have done some research, incl searching
the psubs archives, and I'm impressed with what people are doing.

I got here after deciding to enhance my diving experience by
building a long range / long endurance DPV.

I have some ideas, and would love to get some feedback by all the
experienced people here.

First, a quick overview of my ideas so far. I like the principles
of KISS, so my plan is the use painted plywood sheets as frame
construction material, and, as I'm an electronics engineer, use
electronic controls as much as possible.

My target deep is abs max 200', usefull deep 130', air for 3-4
hours (using 4 80cf tanks), topspeed whatever I can get from std
trolling motors and range 4-8 miles roundtrip.

The basic design is when viewed from the rear:

            |o           o|
            |I   Diver   I|
          O |I           I| O
        ----|-------------|----
          O |  Batteries  | O
            |-------------|
            |             |

And viewed from the side:

       /----------------------------\
      /                             |
     /                  [  ]        |
    <         --------------------- |
     \                  [  ]        |
      \                             |
       \----------------------------/

It's basically a H, with four electric engines 'O', fixed lift on
top 'o', thin variable lift tanks 'I', battery box below, about
where the engines are located, and 4 std scuba tanks in front of
the batteries. The side sheets would be a 2x7' sheet, but with big
pieces cut out to reduce weight and improve view. The 'H' mid
sheet is 3' wide, where the diver would lay on, would be solid
from the rear and 5' forward, leaving room for the diver to look
down. All weights will be at the bottom, and it will have wings
for stability during "flight". I would be designed to be modular
assemblies for easy transport.

So here comes the questions:

1) I'm trying to avoid mechanics, so is it possible to get good
results by using only the four engines for left/right and up/down
control by controlling power to each engine, assuming the DPV has
been set for neutal balance and buoyancy using the variable lift
tanks ?

2) I like those syntactic floats for the fixed lift, are they easy
to get in the shape I need (long square blocks or pipes), or can I
get some standard blocks I can cut to shape ? And sources for
normal people ?

3) I would like to avoid pressure compensation, would a battery
box of plywood be able to withstand the pressure, assuming it has
internal support brackets between each battery and the sealings
holds ?

4) Again for the engines without pressure compensation, would they
be able to withstand the pressure if the shaft is sealed with t.ex
silicone ?
There has been some discussion of that in the archieves, but not
any conclusive if no pressure compensation is used. Somebody
talked about that the Evinrude can go deep, but I would like to
use Minn Kota's, as they seem to have plenty of choices at good
prices.

5) Anybody know a good sources for the underwater connectors in
small quantities and low prices ?

6) Sources for valves to fill and empty the variable lift tanks ?
And any good ideas and/or sources for the tanks ?


Regards,


Soren Kristensen