Commander 147

[Commander 147]

Mike

First I'll address your question about batteries.

As far as batteries go I have done a lot of reading on the subject and part of that research taught me that in a battery bank like you and I need, not only do the batteries all need to be the same model and age, but they should also be in the same physical location. The reason is that ambient temperature can cause batteries to charge at a different rate and get out of balance with each other. Which could possibly explain part of your issue. Destiny will be a coastal cruiser so I probably need more range from my batteries than you would being located on a lake. But also like you the added 500 LB lead pig is coming out of Destiny and I really like the idea of a similar amount of weight going back in, in the form of batteries. So my batteries will be these….


http://www.odysseysoutheast.com/pc1800-battery.php

Four of these batteries will fit very nicely on the cabin floor under the forward end of the cockpit. They can all fit in the same location with square aluminum tube under and between them for air circulation and heat dissipation. My charger has a thermocouple heat sensing unit that will go in by the batteries which will keep them from overheating. If the heat climbs to high the charger shuts down until the temperature drops back to a lower range and then it starts up again. Because these batteries have a very large inrush capability they can be charged faster than many other batteries. But in this heavy charging mode than can also develop more heat. So I may decide I need to add a temperature sensitive fan to the battery bank area to assist in the heat dissipation.


I also like that for the same dollars I can get close to twice the range with the Odyssey batteries that I could get with the Lithium Ion batteries. Those batteries are just too expensive for me.

The progress on Destiny came to a screeching halt for a while. Business got so bad that I was down to 30% of my normal income and it meant that all non essential expenses were eliminated. So I put all my effort into doing what I could to turn that around. Thankfully things are improving again so I am finally getting back to work on Destiny.

The construction of the support beam has proven to be more of a challenge than I first anticipated. I am actually on the second attempt and this one so far is going well. The first attempt went bad when I tried to use resorcinol for the glue in the mahogany lamination. I did not have enough open time with the glue to make it in one layup and so I was forced to do it in several steps. The resulting beam started to seperate when I applied the first 20 layers of carbon fiber. And this is too important to take a chance with so it was back to the drawing board.

For the second shot at the beam I used a tropical blend epoxy (very slow setting) to give me plenty of time to get glue on all surfaces and everything clamped up. The beam came out perfectly. Then I shaped it to fit the underside of the deck (no small challenge) allowing 5/16" accross the entire top for the carbon fiber that would come next. Then I layed up 20 layers of 9 oz unidirectional carbon fiber on the top of the beam. After it cured I ground the edges flush with a belt sander and to my delight when I test fit the beam I had a very good fit.

Tonight after work I plan to get everything set up and ready for the 20 layers of carbon fiber and two more layers of mahogany that will go on the bottom of the beam. Then tomorrow evening I can hopefully do the laminating.

Here are a couple of pictures of the beam in it's current status.

[ebb]

THAT'S BEAU*TIFUL WORK.


you know me. the fly in the ointment...

The quick fix for sagging beams and flattened coach roofs has been thru-bolting a piece of
metal plate across the span to the ole beam. It's in the Manual.

But it occurs to me that a beam of your excellent proportions
could have a 1/4" slice taken out of the center (not through the cabon layer!) - the long way - and replaced with a carbon insert like the one on top. Or of course stainless.
But carbon is the theme here.
Given the stiffness of carbon, and the epoxied-in 'plate' supported against deflection by the wood on either side, you'd have a compression beam that would NOT require a post..... a non-compressable beam.

Beam ends would need minimal vertical support of course.) Just being helpful
(buzzing off then.....)

[Commander 147]

Thanks for the complement Ebb.

Steve Koopman who designed this for me says it will support 7000 lbs. with a 39" clear span between the bulkheads the way it is. There will not need to be a compression post in my commander when I'm done. Take a look at post 119 below and you can see what it will be like when I'm done.

Oh and please keep bing the fly in the ointment. :-)

[ebb]

Jerry,
Always good to have a Steve Koopman on one's side!

Dave Gerr (I bought his book last year0 probably has a formula for the downward thrust of a mast.
7000 seems more than adequate. Not being sarcastic at all.

That arch cannot be flexed, at all.

Therefor you could open up the bukhead even more. Just enough to brace the ends of the beam.
Just mentioning that.
I think what you have come up with
is very nicely proportioned indeed.
Looks and feels right.

[C38]

Jerry,
That is a beautiful beam! Really impressive, can you make two ?

I can't wait to see you get that installed, if it works out as great as it looks like it will, I may have to do the same to my commander sometime in the future.

[Commander 147]

Thanks Michael

I really appreciate the complements from you and Ebb.

I've been a woodworker all my life but I have to admit doing woodworking for a boat is a challenge that I am really enjoying. I like being forced to stretch my abilities because it makes it far more interesting than something simple like building a piece of furniture.

Our boats were built in a manner totally unlike the computerized production lines of today and every one is differant from every other one in many ways. So even though a single concept can be used on all Commanders, no two parts needed from one to the next will be exactly the same. But if you are serious about considering this for your commander and want to study the design a little closer I have attached a PDF of the design Steve did for me so you can see it better.

Like you I can't wait to get it installed myself.

[C38]

Jerry, Thanks for posting the design!

As of right now I have way to many other items on my plate to even think about starting a big project like that! But I do think the concept is great and the execution is looking awesome.

[Commander 147]

Well, I finished putting the 20 layers of carbon fiber on the bottom of the beam and two more layers of mahogany after that. The beam is almost done fabricating. In addition I made the two bulkheads that will support the beam. After I take a little break and post this I plan to go back to the shop and cut the slots in the end of the beam that the bulkheads slide up into. Then it is one more dry fit test to make sure everyting will assemble correctly and it will be time to mix some thickened epoxy and glue the beam up to the bottom of the deck. After that is done it will be time to tab in the bulkheads.

[Rico]

FANTAbulus!

Nice lines to the bulkheads too. (Is this another new set? They look different from above....)

Can't wait to see more pics!

[Commander 147]

Thankd Rico

Yes they are slightly differant. I got to thinking about how I was going to bend the trim that will go on the edge of the bulk head and having a sharp bend in one direction and then another sharp bend in the opposite direction made that unesscessarily difficult. So I simplified it so I would have only one bend and found that I really liked the look also.

[ebb]

Have to say I like the look of the S curves you have in post 122.
It isn't often we get to throw in a few doodahs
that treat the eye and the hand.

Most of the S could be scrolled from a single piece of mahogany
or more easily from two.
Since the trim is not structural, short grain is not a problem
even if the trim is as trim as it can be made. (1 1/4" X 1 1/4" ?)

Looking good!


{Edit: Keeps tickling the old greycells.

Imagine if I was doing it I'd consider GLUING the trim on. NO fastenings, no bungs.
The upper portion will be grabbed at times by fingers steadying their owners.
A damaged piece of trim is fairly easy to replace even if glued on.
And of course THAT will nevah happen!)

[Commander 147]

Ebb

The best part about an opinion is that we all get to have one. :-) You should know that you are not alone in your opinion. Another very good friend of mine who is the best sailor I know feels the same way. But not counting my opinion I have had an equal number of people say they like the new version better than the old. In my mind's eye I tend to like the way I have it now because it is more like the connection at the top of the bulk head where the beam meets the bulk head. I like the symmetry of the new look. And I really don't like short grain or the look of short grain on trim. So I will either steam bend some mahogany trim or glue up thin strips to make a continuous piece of trim to follow the curve.

Oh and I will glue the trim on. I have no doubt that this will be a major place to grab to steady myself and others when down in the cabin.

[Commander 147]

But progress is being made.

My plan is to paint the bulkhead plywood white and have the support beam and support timbers under it along with the mahogany trim on the edge of the bulkhead ( not installed yet...I'm waiting for glue to show up to do the laminate) accenting it. I'm fighting my tendancy for lots of natural wood because I don't want the cabin to be a dark hole when I go down there.

Aft of these bulkheads will be two cabinets. On the starboard side will be the sink cabinet. On the port side will be the stove cabinet. There will be a fold up counter top that will span between them to use when cooking. And the cover for the stove will fold back to create either more counter space or a chart table which will be supported by a drawer that I will pull out.

I worked out the location and support structure for the foot pump that will supply water to the sink. I also have the base almost completed for the thru-hull for the sink drain. I will show that progress later.

[mbd]

Wow! Nicely done Jerry! In the execution of your support arch, you have managed a very elegant merging of the form vs. function dilemma - neither of which is lacking. Your support arch, with the carbon fiber layers looks unusual, but graceful and purposeful. The black carbon lines accent the graceful arch. Kind of reminiscent of Greek temple or the mystical Pi... I love it! Bring on the togas!



My 2 cents: don't fight "your tendency", all that wood will warm it up down below and just add to the elegance of your interior. You'll have plenty of white with the cabin sides, overhead and other fiberglass structures to lighten things up.

Way cool!!

[Commander 147]

Thanks Mike

It's amazing how many hours we put into these boats and it's nice to know others appreciate what we are doing.