----- Original Message -----
Sent: Sunday, July 25, 2010 1:51 AM
Subject: Re: [PSUBS-MAILIST] linear actuator- thruster range
They aren't too expensive & are built for water.
Hello Alan. Thanks for the Lenco link. I had looked at some of
their info before but this link has quite a bit more info. These look like
pretty good actuators. Ball screw driven, O ring sealed, gland seal on the
wires, stainless construction........nice !
The max stroke is 4-1/2 inch but it said it'll push 750 pounds so re-working
the linkage to the shorter stroke would work.
The Firgelli actuators I have are very cheaply made. Not really up
to snuff for my application but an inexpensive way to test the whole concept of
elec. actuators.
The cost of the Lenco's looks to be $284 each and I got a quote
from a Minnkota dealer on their actuators of $ 259.
They both say " fully submersible " but I doubt they're
talking about submarines !
An enclosure would still be required ( with oil compensation
) but the quality design and materials on these Lenco's looks like a good
choice.
On the position indicator, I look forward to seeing your mock-up
and schematics. I'm a big fan of making inexpensive mock-ups to see how
everything fits up and functions.
On a side note, the side thruster mounting I'm using is off-center
and weighted so that in the event of failure the dive plane/thruster will
" fail " in the vertical position and the power stroke pushes the
assembly to horizontal and beyond through the 120 degree arc. The linkages are
stainless with brass " shear pins " in case I smash into something.
The pins should shear off before too much damage occurs to the dive plane
assembly, and the dive plane "drops " to vertical for ascent of the
sub for repairs.
I plan on keeping a full dive plane/thruster motor assembly as a
spare in the tool chest. As a new and inexperienced pilot I'm expecting to do a
lot of "crashing " before I get the hang of this boat. After testing
at depth I'll be putting in a hundred hours or so of self teaching so I'm
confident what the sub will do under various conditions and situations.
A lot of this early testing will be done while attached to the
crane. Things like flooding only one ballast tank, locking out
various systems simulating failure ( air and electrical ), and maybe even
a drop test into the water to see if anything "shakes loose "
I'll be developing some type of seat belts too in case I encounter
a hurricane ( just kidding )
But I want to find out what the sub will do in extreme conditions
and train for it. No riders until I'm confident the thing is " bullet
proof "
As a long time scuba diver I've experienced some pretty scary
situations in deep water and I'll be developing procedures to deal with as many
situations as I can dream up.