Math question: diameter from a portion?

[Rusty Heap]

https://planetcalc.com/1421/

[rwest]

Originally Posted by Rusty Heap

https://planetcalc.com/1421/

Thanks Rusty,

I plugged in the cord and height from my tracing into the calculator; it wouldn’t accept .10 in the height, cord was 1.33, so I base 10 the thing and came up with a radius of 7.21 and doubled for a diameter of 14.42” does my math track, or do I need to correct anything because I multiplied by 10?

Here are a couple pictures.

[rwest]

A couple of you recommended running a trammel on a router, but as you can see from the picture above, it would take a custom bit to make the shape, but a chisel on a lathe could make the shape pretty easily; even with my basic skill level.

Thanks for all the suggestions, that’s why we bring all our toughest quandaries to the board!

[rwest]

Let’s try this again! Watching the video posted, I got out my calculator and punched in my numbers and came up with 4.5”. I set my compass to 2.25” Drew a circle and bingo, matches up nicely. Looks like the lathe is an option.

Probably fairly obvious by now, but I have always struggled with math and really need to prove it empirically to trust my answer.

[id10t]

Only thing I know about lathes is watching some wood turning stuff on youtube because it looked cool and was in my suggestion list...

How do you make a shape like that with a lathe? Start with a 5x5 block of wood and shave it away until you have a 4.5" circle? You'd still need to slice off a wafer and then cut the shape out (looks like you could get 4 per wafer) and then do the other required shaping on them... or is that the plan?

[stomachmonkey]

Originally Posted by rwest

A couple of you recommended running a trammel on a router, but as you can see from the picture above, it would take a custom bit to make the shape, but a chisel on a lathe could make the shape pretty easily; even with my basic skill level.

Thanks for all the suggestions, that’s why we bring all our toughest quandaries to the board!

Get a desktop CNC.

[rwest]

Originally Posted by id10t

Only thing I know about lathes is watching some wood turning stuff on youtube because it looked cool and was in my suggestion list...

How do you make a shape like that with a lathe? Start with a 5x5 block of wood and shave it away until you have a 4.5" circle? You'd still need to slice off a wafer and then cut the shape out (looks like you could get 4 per wafer) and then do the other required shaping on them... or is that the plan?

Pretty close, I would bandsaw it round first, then shape the angle on the face, do the curved part on the outside, slice out the formed wedge, cut the slot and then do any final shaping.