A Math Question: Buoyency

[MrForbes]

A one gallon engine is the Buick 231 cubic inch (3.8 liter) V6. This I can remember.

And a pint is a pound, the world 'round. This I can also remember

so you need to displace two gallons of water (462 cubic inches, which happens to be a 1960s Lincoln engine) to make a battery float (8 pints in a gallon, two gallons = 2 x 8 lbs/gal = 16 lbs), and you need to displace more than that for the rest of the weight of your system.

you do understand about cubic inches, I trust.....just multiply the height times the width times the length (assuming a rectangular box) and you get the volume in cubic inches of your box.

[Molten]

You are a CAD master. Use it. Draw the 'boat' without making the air and parts inside of it. Just don't hollow it. That way you don't have to solve for the volume of the boat. You just draw it and set the density for water. Check the weight, make sure it is more then the weight of the battery and equipment.

This is the way of the true CAD master, young mathawan.

Woah, you all rock! Thanks a ton, I've now got my dimensions all done for a lexan box I'll be making to float in my pool with some sweet lights (FRC green cathodes). The box will measure 14" long by 5" tall by 10" wide. This should be slightly less than twice the buoyancy that I need, which should also give me plenty of room to put in all the electronics. I'll probably upload some pictures once I finish building the thing.


Thanks for the help!

[ebarker]

Originally Posted by squirrel

A one gallon engine is the Buick 231 cubic inch (3.8 liter) V6. This I can remember.

And a pint is a pound, the world 'round. This I can also remember

so you need to displace two gallons of water (462 cubic inches, which happens to be a 1960s Lincoln engine) to make a battery float (8 pints in a gallon, two gallons = 2 x 8 lbs/gal = 16 lbs), and you need to displace more than that for the rest of the weight of your system.

you do understand about cubic inches, I trust.....just multiply the height times the width times the length (assuming a rectangular box) and you get the volume in cubic inches of your box.

You are a veritable plethora of information. It never dawned on me until now that this particular Lincoln engine was twice the size of the Buick and was a gallon versus 2. we've got our selves a regular click and clack contender.

I just did a little punching in the calc and did the volume of 8 cylinders of 4 in bore and 4 in stroke and got 400 cu. I just had to try that out. back in the day the 4x4 happened frequently enough, like in a John Deere Model 40.

[GaryVoshol]

Don't forget to add for "freeboard" in case there are any waves. Don't want to swamp your electrics.