Technical Drilling a hole in the exact center of a disc

Easy for you to say!

 

Some of you guys kicked geometry's butt, didn't you? Do like I always do-eyeball it and be wrong.

 

Not hitting it dead center usually means no 2nd date...

 

okay, I left some of you at the light on that hypotenuse example. Here's another one I thought up. Use your compass to draw a 1 inch circle, cut it out of paper, fold it in half twice. the fold will intersect in the center.

 

Not sure whether you plan on using an electric hand drill, drill press or ?
Drilling accurate(on location and on size) holes in some plastics can be difficult under the best conditions, finding/scribing "true"center using the previously mentioned techniques is only part of the story.
Having been a machinist for years allowed me access to the correct machine tools, but sometimes these were not always available, and I found I could never get hole locations "right on" using a center punch and hammer, but once I discovered the spring loaded center punches (quality ones),, things improved greatly.
Two things that will also make a huge difference is a correctly sharpened drill bit and as I mentioned earlier; the use of a center drill.
Drilling some soft plastics with a too sharp of a drill bit can also be difficult as it wants to spiral the bit in before it has actually removed the material. Slightly dulling the edge of the bit helps reduce this from happening.

 

I thought at first that you were building a suppressor for a firearm.

 

Why not just use the hole the compass left when you drew the circle?

Charlie Stephens

 

Give that man [Charlie Stephens] a Cigar. Winner, Winner

 

Gotta be careful with Hypotenuses....very territorial , kill more people than alligators and lions combined

 

For the following 4 reasons;
1. I was trying to explain radii in it's relation to the circumference of a circle
B. I hadn't thought of that.
d. No other reason, I just hadn't really thought of it, pretty simple and accurate answer Charley.

Next thread, this one is solved.

 

Enter Doctor Mallard:
"Interesting observation, Jethro...'The important part is that the plural of 'hypotenuse' is 'hypotenese'!"
Mmmm, thanks, Ducky...

 

I think that you should glue a few of them to a target paper and take them to the range.
A good .223 at 200 yards should drill a nice hole for you dead center.

 

Blue One indirectly brings up a good point. What caliber (diameter) hole do you need?

Charlie Stephens

 

I thought firearm suppressors were AKA oil filters.

 

So have these isosceles triangles...

 

Wouldn't it be quicker if your tracing your circle already to just fold the paper in half, and then fold that in half?

 

it would be quicker and more accurate to use a machine made centerfinder. the question was "how". i posted a valid reply. now the OP knows how. the next time someone asks how, and there isn't a piece of paper the size required, the theory is there.

years ago i read a book titled The Nature of Art and Workmanship written by David Pye, and English woodturner. he goes on about the "workmanship of risk" and the "workmanship of certainty". i think the former is okay for some situations, and the latter for others.

or ponder the "cheap, fast, good" triangle. you can have only two. if it's fast & cheap, chances are it won't be good. if it's fast & good, it usually won't be cheap. if it's good & cheap, it probably won't be fast. but of course everyone has a buddy who has a friend that can make gold from seawater.

do whatever works for you under the circumstances; run what ya brung.

 

Fair enough.

 

I feel so much smarter, thanks

 

The ancient greeks knew how to do it, but didn't bother to make an app or you-tube clip ... Losers

 

All I know is pie are round and cornbread are square.

 

Except for some good suggestions I have received, I'm almost sorry I started this thread.

 

You cannot drill a hole in the exact center. You can drill the center out, but you cannot drill a hole in the center.

 

Remember that we are all waiting to hear how you drilled the hole.
Charlie Stephens

 

With "twenty-seven 8 x 10 colored glossy photographs with circles and arrows and a paragraph on the back of each one explainin' what each one was" please.

 

MY cornbread is ROUND. Baked in a cast iron skillet.

Ben

 

I took your advice and went to the hardware store and bought a #12 fender washer that was exactly 1" in diameter. I was able to get close enough for my purposes by just holding it on the plastic disc and drilling through the hole. I think I can do better by gluing the fender washer to the protective paper stuck on the disc (it wants to move around if I just try to hold it in place). I was kinda surprised on how hard this is to do (but then, I only have a cheap bench top drill press). I really envy you guys with lathes. A lathe is next on my list after a power washer and then a shop press. I figure I'll be about 80 before I can get everything I need, by which time I'll be too old to use it.

 

or just use a combation square like others said and you'd be good.

 

That is so simple that must be a text book example of "simplifying complicated"

That is so complicated that must be a text book example of "complicating simplicity"

That is so funny!

"we decided that one big pile is better than two little piles, and rather than bring that one up we decided to throw ours down."

Arlo Guthrie's Alice's Restaurant is so funny

Yes and maybe se a picture of how you done it, how it looks drilled, when you put it together and how it all worked out.