Ok, gonna show my ignorance here

[-MIKE-]

Well, I should hope not. After all they've done for us.

[Existential Angst]

Yeah, but if you cut it long, and then razor it as it lines the hole, the fit will be exact -- incl. the angle of the "wall" of the felt, if it were substantial, would also be angularly correct! You could actually glue the overly-long felt in the hole, making the cut very easy to coordinate.

Also, the cut doesn't have to be at all straight, bec the ends of the felt are overlapping, and will match no matter how sloppy the cut -- as long as the cutting knife catches both overlapped pieces. In fact, one could arger against a perfectly straight cut, and could even do a kind of "toilet roll tube spiral" -- depending on what's going in the hole, etc.

For one-offs, this cut'n'match is proly the preferred way. It of course would not be efficient for production jobs.

[Lew Hodgett]

----------------------------------- Standard technique used for doing "Match & Line Up" on a wall paper job.

Works every time with no error.

Lew

[Robatoy]

That type of cut is often called a dutchman. (no joke here...for real)

[Steve]

On the proud day he delivered the boy to the campus, he said to the math professor, "Make sure he gets some of that there triggernometry. He can't shoot worth a damn!"

[Existential Angst]

And, for example, how you cut blades for welding in a blade welder (with li'l scissor/chopper) -- no worry about squareness, straightness, no grinding, nuthin -- until the weld is done, and you grind off the flash.

[Paul]

[Larry Jaques]

"MOM! Bill's feeling up the toilet again!"

-- Fear not those who argue but those who dodge. -- Marie Ebner von Eschenbach

[Leon]

You are not incorrect but for the fun of supposing, the OP is wanting to line a hole with felt. When does a hole transform into a larger opening? ;~) When I read hole, I pictred a drill bit hole, 1/4"~1/2" in diameter. Perhaps you pictured a 4",5",6"+ diameter hole. LOL. I tried to picture putting felt inside a 1/2" diameter hole, and also some how forcing a razor inside the hole. ;~)

[Artemus]

Prezactly. And why has everyone assumed the hole is round? Art

[willshak]

Artemus wrote the following:

because he asked for the formula. If a rectangle, or triangle, all that is needed is a tape measure.

[Artemus]

Another unfounded assumption. It could be an oval. Art

[Leon]

We were all hungry and thinking about pie. ;~)

[Leon]

OR it could be 45379 and three and one half sixteenths sided. ;~O

[Larry Jaques]

QUICK, HIT THE 'CONVERT TO CURVES' KEY COMBO!

-- Learning to ignore things is one of the great paths to inner peace. -- Robert J. Sawyer

[Existential Angst]

Pretty much what I was going to say....