Re: [PSUBS-MAILIST] Need advice, new builder.

["D. Blake" <dblake@bright.net>]

-----Original Message-----
From: Stan Muller <smuller@iland.net>
To: personal_submersibles@psubs.org <personal_submersibles@psubs.org>
Date: Friday, May 11, 2001 1:48 AM
Subject: Re: [PSUBS-MAILIST] Need advice, new builder.


>Hi BigDave,
>   Thanks for the comeback. I know just enough about hydraulics to get
>into trouble. ;-)
>   The first thing I will do tomorrow is to start to check out the used
>book sites for the, "HOW TO DESIGN / BUILD REMOTE CONTROL DEVICES"
>Thanks for the tip.

My copy came from a U.S. Airforce Library down in Texas.  Probably part of
an old book sell-off.  The author's name is Ivan G. Stearne(1981) and the
publisher is TAB BOOKS,inc.  It was obviously written for the amatuer
experimenter.  It has chapters that describe: electromechanical, hydraulic,
Instrumentation, light activated, sound activated, wireless
transmitter/receiver, and even a section on scrounging parts from salvage
yards, old appliances, etc.  Anyway, these "basic knowledge" type books are
a real joy for me to read, and a great starting point to spark the
imagination.  Hey, thats what it's all about eh?

>   As to the peddle power, my sub will be handled the same as my wife of
>40+ years handles me, On a short leash! ;-) I plan to pressure test at
>about 45 feet, That's the deepest spot in the lake, and my max. useable
>depth will be about twenty  feet. My air, communications, electric, will
>all come down to the sub by way of an umbilical from my tender.  This
>will also provide for emergency retrieval, (in addition to drop weight)
>and will limit my dive depth. With this in mind, my cruse distance will
>be limited to about fifteen feet in any direction. I am too old, fat,
>and lazy to expect to go anywhere by peddle power. Even my bicycle has
>electric assist. My Daddy didn't raise no dummies, well there was my
>brother, but that is off topic. ;-)

Yeah, I agree with the other guys.  Too much loss with a hydraulic motor
driven by pedal power.  Gary Boucher has a nice hydraulic system that is
powered by an electric motor/pump arrangement, but no doubt very expensive.
I like Vance's recommendation
Re. George Kettridge UEM design.  You could probably come up with something
similar if you could setup a jig (on the workbench, or picnic table;>) and
experiment with various sized bicycle sprockets.  Look around for a small
but robust 90-degree (right-angle) gear drive, and the rotary thru-hull seal
Dan mentioned.  Some of those gear drives have built in reduction, something
to think about.

>   While I have your attention, what do you think of taking two of the
>same size small hydraulic cylinders, mount one inside the sub, and the
>other outside on the manipulator arm. Fill them both, as well as the
>plumbing, and when you move the inside cylinder the outside one will
>move. That is how I have designed my arm and grabber. if I find I need
>more power, I'll use levers inside to gain the advantage. It seems like
>a down and dirty way to do it, think it will work?

No need to use levers to gain advantage.  That's the beauty of using
hydraulics. You use a bigger cylinder inside than outside to gain advantage
in length of travel and/or applied force.  Oh BTW, sorry to hear about your
brother.  Unfortunantly in my family, I guess I'am the "brother".  My two
siblings are quite successful.  Maybe, in my case, Mom got a weak load
LOL;>)

Later on,
BigDave

>   Write when you have the time, I'm interested in your thoughts,
>Stan, the mathematically and hydraulically disadvantaged guy with the
>sub on the picnic table.