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Posted: 7/16/2013 8:16:33 AM EDT

.45ACP
Calculate how many circles of diameter .480" can fit into a 48" x 30" rectangle.



9mm

Calculate how many circles of diameter .392" can fit into a 48" x 30" rectangle.




The math is way beyond me.




I'm a .45 fan, but was thinking a smaller round like 9mm would give me more detail on the design.







Going to be making a glass covered coffee table, with a sort of mural design done with spent casings under the glass.
Link Posted: 7/16/2013 1:32:39 PM EDT
[#1]
Classic 'packing problem'.

You should  be able to find the solution online for circles in a rectangle.

They can be a real PITA to solve from scratch.

Link Posted: 7/16/2013 4:14:03 PM EDT
[#2]

Thanks for the post!






I found some that I can apply to the area of squares or circles, but the couple rectangle examples I saw seemed extremely complex and on a case by case basis. Couldn't really find a magic formula for it.

Link Posted: 7/17/2013 1:31:43 PM EDT
[#3]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Thanks for the post!


I found some that I can apply to the area of squares or circles, but the couple rectangle examples I saw seemed extremely complex and on a case by case basis. Couldn't really find a magic formula for it.
View Quote

It depend on the length to width ratio of the rectangle.
www.math.ucsd.edu/~ronspubs/03_01_circles_in_rectangles.pdf

It is far from a simple problem.
Link Posted: 7/17/2013 1:33:25 PM EDT
[#4]
.45 ACP close to 6200

9mm close to 9300
Link Posted: 7/18/2013 5:47:56 AM EDT
[#5]
Thanks guys.



Link Posted: 7/18/2013 6:58:02 AM EDT
[#6]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
.45 ACP close to 6200

9mm close to 9300
View Quote


That is correct if you place them in a simple square pattern like they come in factory boxes.

It gets more complicated if you stack them in a hexagonal pattern such as this. I came up with a over 7000 for 45.
I didn't do the calculations for 9mm.

Link Posted: 7/18/2013 9:27:46 AM EDT
[#7]
Discussion ForumsJump to Quoted PostQuote History
Quoted:


That is correct if you place them in a simple square pattern like they come in factory boxes.

It gets more complicated if you stack them in a hexagonal pattern such as this. I came up with a over 7000 for 45.
I didn't do the calculations for 9mm.

http://upload.wikimedia.org/wikipedia/commons/6/69/Circle_packing_%28hexagonal%29.svg
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Quoted:
.45 ACP close to 6200

9mm close to 9300


That is correct if you place them in a simple square pattern like they come in factory boxes.

It gets more complicated if you stack them in a hexagonal pattern such as this. I came up with a over 7000 for 45.
I didn't do the calculations for 9mm.

http://upload.wikimedia.org/wikipedia/commons/6/69/Circle_packing_%28hexagonal%29.svg


Depends on the length to width ratio of the rectangle.

If it does not match the hexagon dimensions you run into problems.

The best method is probably to arrange the cases and THEN decide on the table dimensions, not the other way around.


Link Posted: 7/18/2013 9:42:35 AM EDT
[#8]
Discussion ForumsJump to Quoted PostQuote History
Quoted:






Depends on the length to width ratio of the rectangle.



If it does not match the hexagon dimensions you run into problems.



The best method is probably to arrange the cases and THEN decide on the table dimensions, not the other way around.





View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:


Quoted:

Quoted:

.45 ACP close to 6200



9mm close to 9300




That is correct if you place them in a simple square pattern like they come in factory boxes.



It gets more complicated if you stack them in a hexagonal pattern such as this. I came up with a over 7000 for 45.

I didn't do the calculations for 9mm.



http://upload.wikimedia.org/wikipedia/commons/6/69/Circle_packing_%28hexagonal%29.svg




Depends on the length to width ratio of the rectangle.



If it does not match the hexagon dimensions you run into problems.



The best method is probably to arrange the cases and THEN decide on the table dimensions, not the other way around.









 



Need to sketch it out to see what my design will work with I guess.

Thanks again, maybe i'll see if i can round up a couple thousand and see where I'm at haha.



Link Posted: 7/19/2013 9:50:05 AM EDT
[#9]
If you measure carefully (as in caliper) you could likely scale from a smaller size of tight pack.

You just will not be able to not later the length/width ratio from your smaller 'test' section.
Link Posted: 7/19/2013 12:02:49 PM EDT
[#10]
Discussion ForumsJump to Quoted PostQuote History
Quoted:


That is correct if you place them in a simple square pattern like they come in factory boxes.

It gets more complicated if you stack them in a hexagonal pattern such as this. I came up with a over 7000 for 45.
I didn't do the calculations for 9mm.

http://upload.wikimedia.org/wikipedia/commons/6/69/Circle_packing_%28hexagonal%29.svg
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Quoted:
.45 ACP close to 6200

9mm close to 9300


That is correct if you place them in a simple square pattern like they come in factory boxes.

It gets more complicated if you stack them in a hexagonal pattern such as this. I came up with a over 7000 for 45.
I didn't do the calculations for 9mm.

http://upload.wikimedia.org/wikipedia/commons/6/69/Circle_packing_%28hexagonal%29.svg


Yeah maybe I should have said mine was an estimate, basically an absolute minimum needed number.
Link Posted: 7/24/2013 12:52:09 PM EDT
[#11]

Discussion ForumsJump to Quoted PostQuote History
Quoted:
Depends on the length to width ratio of the rectangle.



If it does not match the hexagon dimensions you run into problems.



The best method is probably to arrange the cases and THEN decide on the table dimensions, not the other way around.





View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:



Quoted:


Quoted:

.45 ACP close to 6200



9mm close to 9300




That is correct if you place them in a simple square pattern like they come in factory boxes.



It gets more complicated if you stack them in a hexagonal pattern such as this. I came up with a over 7000 for 45.

I didn't do the calculations for 9mm.



http://upload.wikimedia.org/wikipedia/commons/6/69/Circle_packing_%28hexagonal%29.svg




Depends on the length to width ratio of the rectangle.



If it does not match the hexagon dimensions you run into problems.



The best method is probably to arrange the cases and THEN decide on the table dimensions, not the other way around.









 
I agree.  That's how I would do it as well.
Link Posted: 7/24/2013 4:58:02 PM EDT
[#12]
Quoted:
.45ACP
Calculate how many circles of diameter .480" can fit into a 48" x 30" rectangle.
9mm
Calculate how many circles of diameter .392" can fit into a 48" x 30" rectangle.


The math is way beyond me.

I'm a .45 fan, but was thinking a smaller round like 9mm would give me more detail on the design.


Going to be making a glass covered coffee table, with a sort of mural design done with spent casings under the glass.
View Quote

So the 48 inch side can hold .48/.48=100 rounds
the 30 inch side can hold 30/.48=62.5 rounds
No 62.5*100=6250 rounds

For 9mm
48/.392=122
30/.392=76
122*76=9272 rounds
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