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Heavy Material Needed

August 10th, 2010, 4:34 pm

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shuphrk88
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I'm working on a project that has modular parts that are the same size but of varying weight, ranging from 5 to 25 pounds.

This is going to sound like a silly question, but I was looking at dumbbells and obviously a 5 pound weight is smaller than the 25 pound weight. I understand that it's a psychological design as well, let's face it, you wouldn't feel like you did much if your 25 pound weight looks as big as the 5 pounder.

But would it be possible to pack 25 pounds of weight into something the same size as the 5 pound weight say, a 3x3x2 inch box?
I'd rather fail than to have never tried
www.coroflot.com/bartliang

Re: Heavy Material Needed

August 10th, 2010, 4:46 pm

GURU
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Go to a hardware store and pick up some lead.

Re: Heavy Material Needed

August 10th, 2010, 4:49 pm

GURU
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Here's a great material weight calculator::::

http://www.matweb.com/tools/weightcalculator.aspx

Re: Heavy Material Needed

August 10th, 2010, 4:59 pm

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shuphrk88
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That calculator is really helpful, thanks! I was going to go with lead, but all its health hazards make me a bit uneasy. Copper is showing potential though.
I'd rather fail than to have never tried
www.coroflot.com/bartliang

Re: Heavy Material Needed

August 10th, 2010, 5:13 pm

GURU
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Lead in it's solid block form is not all that bad... just wear gloves and don't eat it.

Make sure you wear gloves when working with copper. It can turn you skin green for a while.

Re: Heavy Material Needed

August 10th, 2010, 6:27 pm

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loughnane
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tungsten is the densest thing i can think of that is common enough that I've held it in my hand.

But even then you are only looking at ~2.5X denser than iron. No way you are getting 5x
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Re: Heavy Material Needed

August 11th, 2010, 11:39 pm

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Lmo
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But would it be possible to pack 25 pounds of weight into something the same size as the 5 pound weight say, a 3x3x2 inch box?
The technical term for this is, "density".

Which weighs more.... a ton of feathers, or a ton of lead? Which is physically bigger? :wink:

Osmium, at 22.59 g·cm−3 i generally considered the "densest" metal. [tungsten = 19.25 g·cm−3; lead, 11-something g·cm−3]
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Re: Heavy Material Needed

August 20th, 2010, 8:31 am

Sergiy Grynko
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Have you settled on a material for the lighter object? The less dense that is, the easier it is to find something denser that you can work with.

If it's a plastic, your best bet is High Gravity Compound (HGC), which is a plastic with high-density fillers, specifically designed to be dense while still being moldable easily. HGCs are commonly used as strategic ballast in tennis racquets (to modify centre of mass for easier handling) and to make handheld electronics feel more substantial in the hand. Density typically goes up to 11,000 kg/m^3 or ~ 700 lb/ft^3.

Obviously, since it's a kind of composite, you can get any number of densities, depending on filler amount.
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