Lindberg Jolly Roger float test.

E.J. ;

Your " Flattie " will perform well , I have two of them .They were for when My batteries on the big stuff ran down . Having fun with R.C. is always a blast ! .

cool

Don't want to hijack this thread, so started a new thread - Little Wood Flattie build in ships.

EJ

I have been thinking on this and here is a list of mistakes I have made.1.not sealing the gun ports 2.underestimating the weight of the masts,spars rigging and blocks which caused the wild tip when I put it back in the sink.3Perhaps the ship is too small for this to be viable.4.attempting to pour lead shot into the hull without regard to placement and balance.I am sure there are more so chime in dudes if I missed anything.

Complicated?  Shoot, that was the Cliff's Notes version of the Cliff's Notes  :)

GM, what I was thinking  a bit of steel bat, oh 1/4 x 3/4 x 6-8" long screwed on the brass fin.

Ideally, a brass tube screwed to the brass fin, then filled with plumber's solder.

Was not over-concerned about  streamlining, a galleon ought to lumber along  a bit.  A clupper, now, that want's a bit of zip.

Yeah!I guess the whole thing is a lot more complicated than I thought.

I think you are a little generous with your BWL and DWL, but we both got the same results.

Somewhere between 1 and 3 pounds, so lets call it two. All at water line or lower.

A cubic inch of steel weighs 4.5 oz. so a seven inch long by 1" square bar weighs two pounds. I would have guessed more, but so be it. Or a ten inch long 1" diameter bar.

Now as far as pennies are concerned, a current one weighs 2.5 grams. About twelve pennies to the ounce, one hundred ninety two to the pound. Four of those bank roll ups get you to two pounds.

Philo, it's not ugly if its underwater. only the fish know.

Your Thermopylae would actually be a really good candidate for a pond floater. There is a lot of depth there in the hull, plenty of room for experimentation.

And MOST importantly, no open gun ports.

philo426

I guess there is a formula

Well, buoyancy follows rules.

Measure waterline lenght (exclude rudder and keel)
x
beam width at widest at waterline
x
maximum draft waterline to top of keel

Multiply that sum by, oh, 0.67

That's your buoyant volume in whatever cubic units you used. 

A cubic foot of tap/pool/pond water weighs about 63 pounds.

Let's tack some values together.   LWL 11; BWL 5; DWL 2.38  thus 130.9 * .67 = 80-703 cubic inches. 
1728 cu.in. per cu.ft., so .005084 cubic feet.  Multiply that by 63, for 3.2030#.  Weigh the kit and subtract that from 3.2# to get your needed ballast weight.

But, there's a problem.  The kit CG (Center of Gravity) is way above where it would be in an actual ship.    This is why there are recommendations for a longer /deeper keel.  This is the loger the CG closer  to  the prototype's CG (just beloe the main deck, like as not.  The long moment arm also offset the undo forces wind will have on the top hamper.  Some of the "missing" ballast weight would need to be on that keel..

That keel could be as simple as some brass sheet, say 3" wide & 6" long with a steel plate along its edge, and a set of holes mactched to holes through the solid part of the keel, then fastened with a small seto bolts and nuts.  Or, a cotter pinof suitably small sixe.

I guess there is a formula.Some guys put a weight on the bottom of the ship that might be effective but sure is ugly!

NNNggghhhh...

About the only thing you can do is hope to replicate the vertical center of gravity- in every other way scale will defeat you because for every increase in a given dimension, the mass increase is a cube.

I'd guess the center of gravity on that ship was well below the waterline.

But getting to that waterline is the trick. In addition to whatever mass you need to get the CG low, you also need mass to displace the water. I can't guess the displacement volume to the waterline of that model, but let's say it's 24 cubic inches- 12" x 2" x 1'". A cubic inch of water weighs about 0.6 ounces (did the math).

So the displaced weight is 14 ounces, almost a pound. And that all has to be below the waterline along with whatever you need to account for everything above the waterline.

That gets you to the tipping point.

Thats all I wish to contribute.

Wow!4 pounds!

Philo426

    The real ships were ballasted mostly with a stone that was chosen for the job . Round smooth river stones .Then the Cannon Balls not on deck and Most of the stores and powder as well as spare mast parts and spars were carried well even with or below the water line .

   Even the addition of her rig and guns were taken into account . I think some of those boys back then knew about how much the bare ship weighed too ! When I did my " Constitution " in Cal . I had a two and a half inch false bottom on her ( outside ) to allow for the weight and masts .The keel was about four pounds total and hidden by the false bottom .           T,B.

Proff.

I do have to agree with you . I built one of these as a gift and the lowest flange on the foremast is supposed to be sitting right on the deck ! I would worry about that height , definitely .

I wonder if I can ballast my 1/600 Titanic or wold it dot he same thing?

You know the saying "scale doesn't fly".

We can add the saying "scale don't float".

Makes you wonder how the real ships were ballasted.Who would have thought the plastic masts ,yards and rigging would add up to throw the balance off so radically !

IF you ever decide to try a floater again, three things.

1. There's no point in ballasting the hull ahead of time. As you foud out, it can create all kinds of fit problems later. And you couldn't accurately predict the final weight of the model.

2. All of the mast gear weighs so much more in comparison to that hull, that you created an artificially high center of gravity. So it tips over.

3. The only way to make a pond sailer reliable is to have an artificial keel. Well maybe not the only way, but certainly the most reliable and practical way. If I were to do it, I would have put a downward pointing keel dead center front to back, 2" fore/aft in width and 12" or 2/3 the height of the masts downward length. Something fairly rigid like a piece of 18 gage aluminum.

Set it in the pond, and assuming it doesn't immediately sink, clamp a small weight on the bottom end of the keel. Then adjust the amount of weight until the waterline is where you want it, with a margin of safety.

Then try moving the weight up the keel, testing its stability as you go. When you get to a comfortable point, stable but a little soft as far as heeling, clamp it permanently, cut off the remaining aluminum and paint it all black.

Thats how I do my pond sailboats.

Finished up the rigging but the float test did not go well!The ship either listed to port or starboard and the addition of lead shot only caused water to pour in and sinkit!I guess it will have to remain in dry dock display!   

Thanks guys. I like the wood kits, especially the boats, like the flattie, Titanic lifeboat, Lobster smak and skiff. They are quick to put together, plus, having been a builing contractor and carpenter most of my life, working wood just seems to come natural. Plus, they are a 'change up" from plastic kits so I don't get bored.

EJ

Looks really good!

Did I read the scale o nthe box right, and that's 3/8" = 1'-0" ?  This can be a great scale to work in with the Midwest kits.

OK!Can you post a pic of it?

Yes i will!By flattie do you mean aircraft carrier?

Nice video. Will you do one when you float it? I'm doing a wood kit, a flattie that has been requested to see how it does in the tub. Not sure I want to do that though.

EJ

clic the pic to view the clip

Sewed on the jibs and bow sails.   

I have found that use of thread to be effective in correcting the warp at the top of the foremast.