Find The Center Of A Circle : The easiest way I know.

This method of finding the center point of a circle is Thales Theorem, which uses the outside of the circle instead of the inside of the circle. It is the fastest way I know of using tools that most people have in their tool arsenal.

[charlesdusautoy]

Sure the centre finder makes you draw off-centre. So just flip it, draw again, and it'll make to extremely close parallel lines. Same for your intersecting lines. And you end up with a tiny parallelogram enclosing the true centre.

[mikecrook]

Nothing to build or "buy" for the purpose of finding the center of a circle. I just went out to the garage and tried it myself. How Great!

[willb]

After watching all these videos today, I just got a sudden urge to go to the garage and play with circles. 😎 All your videos (not just today's) are high quality content, but today you also passed the quantity test.

[ahgdubh]

Absolutely brilliant. You just saved me a good chunk of change by using tools I already have. Thank you.

[MattLitkeRacing]

I like learning new ways to layout parts. These 3 videos were very informative. For more precise parts I will use layout fluid or a Sharpie and a scribe

[glennmcgee]

Easy peasy, much better way than other methods, thanks.

[danilosbusebosc]

Bravo! An ingenious idea, without having to buy or build a tool to find the centre!

[knifetex]

Nice trick! I use those Silver Streaks all the time at work to mark defects. Back when I was a welder, an older guy blew my mind when he showed me that the cap came off and had a sharpener inside. Made layout more precise. Most people I show that to- to this day didn’t know about the “hidden” sharpener.

[scrapperstacker]

That is a great tip. Thanks for sharing!!

[Must_not_say_that]

Good method, simple and quite straightforward.
You could also use it for a flat plane circle by using the points of a divider placed on the circle and butting the square against the points.

[fvmssze]

That's a pretty neat trick. Thanks for sharing this

[jonathanbailey]

Thank you very much for sharing that was extremely useful

[terrencehill]

Fantastic video! Thank you so much for this!

[gjaeigjiajeg]

Great vid! Thanks for showing this. I'm gonna try this method with one slight modification to fix up the true centre issue:

I'm going to put a piece of masking tape where the centre approximately is, then with the true centre, I'm going to run a scalpel to ever so slightly score the tape area right up against the true centre. And do that 3 to 4 times to triangulate the exact centre.

[ddu]

Nice !! That's it. Just nice and easy ....

[chrisfyfe]

Outstanding ! You are a great source of info ! B.T.W. I have a leatherman Sidekick in near Virginal condition, that I will gladly gift to you . I gets little carry time, which is a Sin! Largely due to your input, my main Multitool battery is the Surge + Bit adaptor and Whia bits, for work, and Spirit X with a Leatherman adaptor which fits the Whia bits . Can’t beat the Spirit for elegance and compactness ! Again if you are interested the Sideclip is yours !

[yevrahhipstar]

You don''t have to be spot-on; you're looking for the centre of a very small error. Great use for a speed square. Wish I'd been shown as an apprentice steel fabricator how damn handy those things are for marking around steel sections.

[eyewaves...]

like it...another easy way is set the right angled piece as outside the circle to form two tangents. Then draw two right angle lines from the tangent contact towards the center of the circle. Where they cross is the center..

[Kleiner_Lutz]

Man, I gotta tell ya, when I watched that first video for finding the center I spent the next 15-30 minutes thinking of ways how to pull this off at work (especially when my boss sees it, cause he's mr. Know-it-all). Now with the new video I want to show off even more 😆😆😆

[larryseibold]

This is great. I want to point out something you did naturally that worked in your favor. You held the two parts together and didn't reverse or flip them. If you would have clamped them and done that simple rotation around the circumference with the assembly, the square could have been off by a little bit (say 89.5 deg), or the speed square (say 44.7 deg). When you make three or more tick marks in the center, the tiny circle will be exactly the center of a perfect larger circle.

Similarly, i guess you could have used the Starrett and had a set of lines forming a tiny circle around the true center, a pencil width away, but the fat line is even fatter here.

All bets are off if the outer circle is not circular, but it should still be close to the average center.