Scaleing

[RANCHI OTTO]

Ranchi was never with his father on a lake when kid....your image is beautiful!

When kid I went to fish with my father but in salt water and .....from a pier!

[Raggi_Thor]

Ranch, I actually use 1 for all kinds of water :-)
That gives me a safety margin in saltwater, boats ussually grow heavier than we think.

[Raggi_Thor]

I suppose you thing G is 9.8 also?
OK, that's it :-)

[RANCHI OTTO]

g = 9.81 depending where you are...

1026 depending where you are too due to the salinity of water....

1 depending on the purity of water...

all is relative in this world......

[RANCHI OTTO]

For you I suppose g not G is 9.80665 m/s^2 at sea level lat. 45.5°......

[RatliffFranklin]

Originally Posted by Quicksilver

I've got a question I've been wondering for a long while. How do you scale weight. Is there a formula? See I'm into modeling boat and weight doesnt scale.

For example I've got a jet boat that is a 1/12 scale Chaparral Villain IV The model is 30" long, weighs about 4lbs. That would mean the real boat would weigh 48lbs . Oh and it goes a mind blowing 300mph, but looks like it's going about 60-70mph scale, actually doing 25mph. Maybe I'm thinking too hard.

Let's take 1/10th scale to keep the math simple

1/10th width x 1/10th length x 1/10th depth = 1/1000th weight

So let's say you have a model that's 3 feet long and weighs 4 pounds.

At 1/10th scale that model would represent a boat 30 feet long weighing 4,000 pounds.

[Quicksilver]

thank you for the replies. Another question though, is 4000lbs reasonable for a boat that large? I don't know how much the Villain IV weighed, but it had 454's. http://powerboatlistings.com/view/2116. Mine sits in the water a bit low too

[RatliffFranklin]

Originally Posted by Quicksilver

thank you for the replies. Another question though, is 4000lbs reasonable for a boat that large? I don't know how much the Villain IV weighed, but it had 454's. http://powerboatlistings.com/view/2116. Mine sits in the water a bit low too

Whether 4,000 pounds is reasonable depends less on the hull and more on the type and number of engines.

[RANCHI OTTO]

The displacement for the CHAPARRAL VILLAIN IV is according to tech. description in a spanish web of 3'500 kg (7'716 lbs) equipped with 2 x 365 hp.

I don't know if this figure is for fully loaded, half load or empty....

[Quicksilver]

huh, see this is why I asked, 7lbs would be one heavy model, it would take a lot of power to get it out of the hole, I try putting 7lbs in the hull and see what the waterline looks like. I'm not really serious about getting the boat scale or anything, just interested in the subject.

perhaps I'll try putting about 3/4 of a gallon of water in a jug in the empty hull, that would add up to around 7lbs. There's 3ft of snow on the ground, but luckily I have my trusty Rubbermaid test tank.

[Raggi_Thor]

Isn't your scale 1:12?
Then 7.716 lbs / 12^3 = 4.47 lbs

[RatliffFranklin]

Originally Posted by RANCHI OTTO

The displacement for the CHAPARRAL VILLAIN IV is according to tech. description in a spanish web of 3'500 kg (7'716 lbs) equipped with 2 x 365 hp.

I don't know if this figure is for fully loaded, half load or empty....

In that case a proper representation at 1/10th scale would be 7.7 lbs with .720 horsepower

[jim lee]

Is there a yacht you have in mind? What changes do you envision?

Well in my case, yes there is!

My J/35. I just LOVE the boat. It was perfect in every way possible.. (IMHO) Until I had three kids. More room would be nice..

Every larger boat I've seen is full of interior. Bathrooms, bedrooms, powder rooms, etc etc.. I just want a bigger J/35! Something can pack more kiddies and food into. And, I want it to sail like a J/35 should. 45' or so feet long?

Is this possible? Would a scaled up J/35 still sail like a J/35? And how could "Sail Like a J/35" be measured?

Many thanks in advance!

-jim lee

[Raggi_Thor]

J/42?

[jim lee]

Naw, I don't like the other J-boats. Too full O' junk inside.

-jim lee