Re: [PSUBS-MAILIST] Subdate

["James Frankland" <james@guernseysubmarine.com>]

Hi Everyone.

Just reading this post from Vance on his Kboat modifications and in particular those side thrusters.

Im very tempted to do the same and ditch the side thrusters in pods as shown on the plans.  Use Minn Kota motors instead as a lot of other people have done - it just seems simpler.  BUT, im not sure how to go about this.

Some questions.  Sorry if these are obvious but im not sure on this modification.

1.  Do people just buy the standard Minn Kota outboard motor complete with the bracket, leg, controls, handle, battery etc and just modify the motor part?  or can you get just the motor and prop on its own?

2.  Whats the through hull design?  A straight forward twin O ring through hull on the outboard shaft?

3.  Compensation.  Oil, ambient air pressure regulator?

I've actually made the two 1" through hulls as shown on the plans for the standard K350 side thruster pods, but im not going to fit them just yet.

Lots of people use these motors so it must be reasonably simple.

Any advice guys?

Thanks
James




I'm worried about weight on the 1-man K boat. Payload is at a premium. However, I'm ditching the old steel cans and the 3hp motor/1/2 hp side thrusters in favor of the Minn Kota 101s, figuring on improved thrust and substantially less weight in the process. I'll look into the SS sheet. My brother works in a machine/fab shop, so we can do pretty much anything we want to. The Perry tanks were 14 gauge as I recall. They oil canned a little over time, but we walked all over those puppies all the time, so they are strong enough to sit out there without protective fairings.

One of the real bonuses about moving the tanks from the old Kittredge style is visibility. That forward tank is in the WAY, not two ways about it. Of course it will tow like a miniature shipping container, so that's something to think about as well.

I'll be doing a picture series on this rebuild. By changing tanks, thrusters, steering, valves,?et al, it's a way to show the guys how to bring the sub up to date while using the stock pressure hull design.

When are you coming to Daytona? I'm thinking mojito here.

Vance


-----Original Message-----
From: ShellyDalg@aol.com
To: personal_submersibles@psubs.org
Sent: Tue, 9 Jun 2009 12:04 pm
Subject: Re: [PSUBS-MAILIST] Subdate



Hi Vance. Those pictures of Carsten and Emile's sub are really good, and show a lot of good ideas along with some first rate workmanship. Very impressive.

They also show the differences between the new technology/design in comparison to the original Kittredge boats. Incorporating some of those innovations into a re-build of your K boat would be great to see.

As it applies to the fairwater tanks, it seems like a good bit of work. One of the things I like about the K boat design is it's simplicity. The FRP shells being a combination of tanks and fairing there by serving dual purposes is good in it's simplicity but presents a slight increase in risk.

The Kreidersub is using aluminum as tanks, which seems to me a good idea. Metal tanks will take a lot more abuse than FRP. The saddle design versus front/back like on the K boats also adds surface stability and deck space. Both good improvements that should be fairly easy to add to a K boat. ( OK, maybe not so easy, but still good )

My comment on this would be to suggest stainless rather than aluminum.

The FRP shells could be modified ( saved ) to cover the added saddle tanks and still serve as fairings. I've made my fairings about 1/4 to 3/8 inch thick FRP ( up to 1 inch in critical areas?)?and I'm confident I can walk on them without worry.

The stainless tanks can take a serious "hit"?without leaking, unlike the K boat shells. They will get dented, but would really have to hit something hard and sharp to punch a hole or blow out a seam.

Aluminum is good, but stainless is better at resisting corrosion, and much stronger on impact.

The cost difference between stainless and aluminum isn't that great, and thinner stainless can be used due to it's increased strength. Also, stainless is easier to weld, and more ductile than aluminum, so shaping it is less risky where cracks on tight bends could be a problem with aluminum.

I had originally planned on using FRP for my tanks, but decided that "cracking" them on the rocks was too risky. Then I went with 16 gage stainless, covered by FRP fairings to keep a sleek and snag free shape. Well, as you see, I ended up with increased thickness on the tanks, ( 12 gage ), eliminated the lower fairings, and saved a big chunk of money and the extra work associated with producing the lower fairings.

The Kriedersub is a fine example of the evolution of the basic K boat design, and I'm sure that future designs will be along those lines.

As it relates to a rebuild, these new ideas seem like?a worthwhile?endeavor with the added stability and resistance to crashing.

Have you got any pictures of your sub? Sure would be nice to see a re-fit in photos as it progresses.

Looking forward to seeing you soon and sharing some ideas over a drink. Frank D.??


A Good Credit Score is 700 or Above. See yours in just 2 easy steps!