Starfish Challenge

[MatthewV]

So here is a challenge:
I am making a dodecahedron with stained glass pentagons. The edge of each piece is five inches. How much will the entire piece weigh?
Standard stained glass is being used. Each piece uses 12-14 feet of copper foiling and solder. I will happily answer any questions to the best of my ability. The person who gets the closest will get a prize of some sorts.

I hope people take the time to calculate out something. This is an engineering problem; you have full access to any resource you want. The deadline is when I finish the project, hopefully mid-September.

Guesses my be submitted by PM or posted in the thread. If you post in the thread, expect other people to see it.

[bgg1996]

[3iff]

Isn't that cheating?

[MatthewV]

[MatthewV]

How thick is the glass?
I havent measured it and there is some variations in the thickness. The copper foil is 7/32 of an inch and it is about twice the width. Some of the pieces have more texture than others. The clear glass has little bumps.

Do you have data on the mass of a square inch of glass.
No I don't. It is normal glass as far as I know.

Is this 'bought' glass or home/custom made?
The glass was purchased.

How thick and wide is the copper foil?
7/32 wide and 1.2 mils thick.

What is the solder made of?
I only use a lead free solder. Lenox brand, the same stuff used on copper water pipes.

I take it that there will be a number of glass pentagons that will be joined together by copper/solder into a large 'glass' dodecahedron?
Yes, there will be 12 pentagons that will be joined with solder to form the dodecahedron. There will be no openings and it will be empty inside.

And the weight will be taken with some scale at UAF.

[3iff]

Any idea how much solder (length of solder wire) you might use for one panel? At the moment my 'estimation' is using far too much...

[Zag]

Experimental evidence is going to be far more valuable than theoretical, because you'll have to make too many assumptions in the application. So, you've made a bunch of these starfish pentagons so far; how big is one of those and how much does it weigh?

[MatthewV]

I don't really know how much solder is used. A few feet from the roll on each pentagon?

I don't know how much they weight.

Every edge is 5 inches long.

And I think that with the correct assumptions, one could get an answer within a quarter pound or less.

[itisally]

Do you have the model number of your solder?
_________________
I could agree with you, but then we would both be wrong.

[MatthewV]

Lets see... there is WS15086 and WS15041. I think the project will finish under the WS15086 solder.

I am not keeping track of how much solder is used. I use solder for other projects and have already purchased 8 lbs for future projects.

[Courk]

Where are you getting the glass? What's the item number on it?

[MatthewV]

I purchase it locally so there really isn't an item number. I couldn't get similar pieces unless I took a scrap piece to the store.

This isn't a lateral! Counting the number of bumps isn't going to get a better answer!

[MatthewV]

All the panels are complete. I don't have very many guesses...

Considering the wide range of calculated answers, a reasonable random guess does have a good chance

[MatthewV]

I have started to assemble the pieces!

[3iff]

Good luck...don't drop any of them...

But if you do, weigh all the bits.

[itisally]

I am really anxious to know how close we all are. I hope the assembly if going well. I took lots of liberties in my calculations, and I hope that my guesses are not too far off.
_________________
I could agree with you, but then we would both be wrong.

[MatthewV]

I will weight it soon!

[itisally]

Breath taking!
_________________
I could agree with you, but then we would both be wrong.

[MatthewV]

Lets see.. I have guesses from

MatthewV
JaneV (my mother)
ThomasK (Facebook)
AndrewV (a brother)
JohnV (another brother)
itisally
3iff

[bgg1996]

Didn't I send one? Right above 200?
_________________
The one member below 18

[MatthewV]

Yes, as it was planet dependent I guess I didn't take it seriously enough... OK, I added you.

[bgg1996]

How soon is soon for you?
_________________
The one member below 18

[MatthewV]

This horrible thing called depression came upon me last week. Thank you for the reminder.

[bgg1996]

I definitely did something wrong in my calculations...
_________________
The one member below 18

[MatthewV]

Were you thinking it was a solid piece??

[bgg1996]

What I think might have happened was I may have converted square inches to square feet by dividing by 12.
_________________
The one member below 18

[itisally]

When I saw the picture I really thought that I was way too heavy. I must have made a few good guesses.
_________________
I could agree with you, but then we would both be wrong.

[itisally]

I was wondering if you forgot about us with that crazy rule game. Any final number?
_________________
I could agree with you, but then we would both be wrong.

[carrier_of_the_arch]

That dodecahedron really is quite a beautiful bit of work, well done!

[itisally]

Hate to nag, but.... Did you get a final weight. Honestly, I talked to my dad about it and we are just wondering how it came out.
_________________
I could agree with you, but then we would both be wrong.

[MatthewV]

Persistance is a wonderful quality for other people to not have!

3217 grams. So 7.092 lb

[MatthewV]

Oh, and if you send me an address, I will mail you a nice handmade ceramic bowl. You may request a particular design but then it will take a few more weeks :-)

Or maybe it will be a cup/saucer.

[itisally*]

Wow! That was close. I was pretty sure I had over estimated the glass.