# No math way to divide circumference of a dowel into equal parts



## Gaffboat (Mar 11, 2012)

Many of you already know and use this trick but just in case you don’t I thought I’d post it.

I wanted to drill six equally spaced holes in the circumference of wood dowel that is about 1 1/4” in diameter. I could get out the calculator and determine the circumference with the pi x d formula and then divide that by 6 and try to measure and mark. But there’s an easier way.



First mark a line at any spot on the circumference.

Then align the mark with edge of a sheet of paper.

Roll the dowel along the paper until the mark hits the paper again and mark the spot.

Extend the marked line down the page and align a ruler so that you can mark equal parts between the edge of the sheet and the line. (I know you’ve done this before.)

Mark the divisions at the top of the sheet.

Cut a narrow marked strip from the sheet and wrap it around the dowel so you can mark the divisions.

That’s it. No math, no trouble, and you end up with nicely spaced holes.


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## CharlesWebster (Nov 24, 2015)

For sixths, you can use a compass set to the radius of the dowel. Pick one point on the edge and swing an arc around that point. Repeat using the end of each arc until you have a 6-pointed figure on the dowel. No math, no measurement, just basic geometry. 

Only works for six sides/points though.


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## vindaloo (May 30, 2009)

Now Oliver's made me wonder what this 6 spoke wheel is for, what's he making now!!!??!!?!?


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## Tonto1 (Nov 10, 2016)

Just mark the center line & measure off 60 degree angles.


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## Cherryville Chuck (Sep 28, 2010)

Clever method Oliver. Thanks.


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## jw2170 (Jan 24, 2008)

vindaloo said:


> Now Oliver's made me wonder what this 6 spoke wheel is for, what's he making now!!!??!!?!?



hehehe, he always posts a teaser when starting a new project.....:grin:


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## schnewj (Nov 18, 2013)

*Heeeerrrreee We Go, Again!!!!!!!!!!!!!!!!*



jw2170 said:


> hehehe, he always posts a teaser when starting a new project.....:grin:


Truer words were never spoken...:grin:


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## Roy Drake (Feb 10, 2014)

Somewhere, there's probably a devil in his detail.


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## RÖENTGEEP (Feb 18, 2014)

Cherryville Chuck said:


> Clever method Oliver. Thanks.


+1 :wink:


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## old55 (Aug 11, 2013)

We will all just have to sit back and see what he comes up with.


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## furboo (Oct 12, 2015)

CharlesWebster said:


> For sixths, you can use a compass set to the radius of the dowel. Pick one point on the edge and swing an arc around that point. Repeat using the end of each arc until you have a 6-pointed figure on the dowel. No math, no measurement, just basic geometry.
> 
> Only works for six sides/points though.


This generalizes ... with a little math :surprise:

Set your compass to

2 * dowel_radius * sin(180 / N)

where N is the number of intervals you want. N = 6 gives dowel_radius, because sin(30) is 1/2. Make sure your calculator has "degrees" turned on for sin, or use pi instead of 180. Equivalently, it might be easier to use

dowel_diameter * sin(180 / N)

But I think I like Oliver's approach better.


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## JFPNCM (Dec 13, 2009)

:smile:Looking forward to the next post as to what one does with a spoked dowel. Perhaps a new cog in........... Don't :blink:


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