[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PSUBS-MAILIST] linear actuator- thruster range



Hi Frank,
On the safety note; I'm bi-passing my pulse width modulators with
a simple on / off & reverse switch, so if they fail I can quickly switch
to full on in forward & reverse. I believe someone missed the conferance
because of a PWM problem.
I'm now investigating using the linear actuators in conjunction with
Vance's suggestion of "rack & pinion" for controlling the dive planes, as
the linkage I thought up has too much "slop" in it.
Herve Jaubert put me on to the lenco actuator. He uses them on his ambients
& tested them to 130ft. I agree they would need compensating for our purpose.
The lack of electronics in them is a plus.
Check out this Florida site. Their Lenco actuators start at $130- & go to $240-
for the 4&1/2" stroke.
http://www.rivermarinesupply.com/xcart/catalog/product_11353_Lenco_Actuator__Lenco_Standard_101_Trim_Tab_Acutator.html
Alan
----- Original Message -----
Sent: Sunday, July 25, 2010 1:51 AM
Subject: Re: [PSUBS-MAILIST] linear actuator- thruster range

In a message dated 7/23/2010 1:23:38 P.M. Pacific Daylight Time, alanjames@xtra.co.nz writes:
They aren't too expensive & are built for water.
Regards Alan
 
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.
Good link.....Thanks.
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.
Frank D.