Formula needed!!!

[Jens Jensen]

I am going to be building a 8 foot octagon picnic table this winter for a relative. Is there a formula to use to get the octagon started or do I need to scale it out and go from there?

[Jens Jensen]

Yes that is the one I found last night and posted,Thanks anyway

John Schaben said:

This may be a bit off thread but here's a little trick for translating decimal numbers to fractional.
Multiply the decimal number by an arbitrary number you want for the denomonator of the fraction, I usually use 32 as it's easy to reduce. The nearest whole number of the result becomes the numerator of the fraction.
example: decimal 0.163 multiplied by 32 is 5.216. Therefore the fractional equivalent is 5/32.
or 0.181 times 32 is 5.792 or 6/32 which would be 3/16.

[Jens Jensen]

Sounds as if you are a math major thanks

Jens Jensen said:

Yes that is the one I found last night and posted,Thanks anyway

John Schaben said:

This may be a bit off thread but here's a little trick for translating decimal numbers to fractional.
Multiply the decimal number by an arbitrary number you want for the denomonator of the fraction, I usually use 32 as it's easy to reduce. The nearest whole number of the result becomes the numerator of the fraction.
example: decimal 0.163 multiplied by 32 is 5.216. Therefore the fractional equivalent is 5/32.
or 0.181 times 32 is 5.792 or 6/32 which would be 3/16.

[John Schaben]

Not really, just a little tidbit I picked up and have found useful, thought some others might also.



Jens Jensen said:

Sounds as if you are a math major thanks

Jens Jensen said:

Yes that is the one I found last night and posted,Thanks anyway

John Schaben said:

This may be a bit off thread but here's a little trick for translating decimal numbers to fractional.
Multiply the decimal number by an arbitrary number you want for the denomonator of the fraction, I usually use 32 as it's easy to reduce. The nearest whole number of the result becomes the numerator of the fraction.
example: decimal 0.163 multiplied by 32 is 5.216. Therefore the fractional equivalent is 5/32.
or 0.181 times 32 is 5.792 or 6/32 which would be 3/16.

[greg darrow]

Thank you Mr. John S......the trick for translating decimals to fractions will come in handy....the main reason for my construction caculator was my lack of ability to do this, but with your trick it is much easier.

[Hal Schmidt "Woodmeister"]

See http://mathworld.wolfram.com/Octagon.html

[John Schaben]

Jens, this may be useful to you.
http://www.buildeazy.com/newplans/octagonal_picnic_table.html

[Jim Siniawski]

hi ,

It took years for me to find this formula.I knew there had to be one. I refered back as far as an 1937 old Audels carpentry book. it said to use 13 instead of 12" when laying out for an octogon. I found this formula in a how to magazine.

Use 2.414 and divide the size (You want to use)by it . your case would be

8 foot divided by 2.414=3 '3 3/4"per side this is as close as you need to be for what your doing . If you use a construction master you have to do several steps to check this but its close enough. to the 1/16TH

i used this to find the sizes of and octogon roofs.

Hope it helps

jim In pittsburgh

Go steelers

get well Sidney

[Michael Campbell]

Thanks for the sites,  i will use them

[Jens Jensen]

Thanks John this is much easier to do

John Schaben said:

Jens, this may be useful to you.
http://www.buildeazy.com/newplans/octagonal_picnic_table.html

[Jens Jensen]

Thank you. Mentioned Audels I  have no idea what ever happened to my fathers collection but I sure wish I had them

Jim Siniawski said:

hi ,

It took years for me to find this formula.I knew there had to be one. I refered back as far as an 1937 old Audels carpentry book. it said to use 13 instead of 12" when laying out for an octogon. I found this formula in a how to magazine.

Use 2.414 and divide the size (You want to use)by it . your case would be

8 foot divided by 2.414=3 '3 3/4"per side this is as close as you need to be for what your doing . If you use a construction master you have to do several steps to check this but its close enough. to the 1/16TH

i used this to find the sizes of and octogon roofs.

Hope it helps

jim In pittsburgh

Go steelers

get well Sidney