Jump to content

Heptagons, the easy way


SorryNotSorry

Recommended Posts

SorryNotSorry

Symmetrical 7-sided polygons like heptagons and 7-pointed stars can be a challenge to draw, even with a ruler and protractor, because 360 doesn't divide by 7 into a round number. But I needed something more accurate than the draft I was using, because all of my guitars will have heptagonal sounding boxes, so needless to say I needed a more accurate template, preferably a large one.

 

I decided I'd go the circumference route: look around the house and property for anything round and large enough with a circumference easily divisible by 7: pots, lids, wheels, etc.

 

It turned out to be a short search. I'm not making this up when I say I found it in the first place I looked. 

 

The base of a 5-gallon plastic pail from Home Depot has a circumference of exactly 84 cm (84 / 12 = 7).

 

To plot out 7 symmetrical points of reference, use a tape measure and a Sharpie to mark off every 12th cm around the outer bottom edge of the pail. Then place the pail on the writing surface of your choice which measures at least 11x11 inches, make marks on it that correspond to the Sharpie marks on the pail, and voilá, you'll have 7 nearly perfectly spaced points of reference without any need for a protractor.

 

I envision the tool and die maker who made the mold in which thousands of those plastic pails have been made... he winks and smiles that I've found one of his Easter eggs. ^_^

Link to post
Share on other sites

Cool idea. I'm an enthusiast for old aircraft (not a pilot, I like their history) and always have trouble when making a sketch of a 7-cylinder radial engine by hand to show people how they worked.

Link to post
Share on other sites
SorryNotSorry
21 hours ago, coyote55 said:

Cool idea. I'm an enthusiast for old aircraft (not a pilot, I like their history) and always have trouble when making a sketch of a 7-cylinder radial engine by hand to show people how they worked.

Tell me about it. I was the only kid in high school who was really into WW2 Japanese aircraft, most of which used 14-cylinder, 2-row radials.

Link to post
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...