Exhausted all searches with no results.there is a way to determine a radius using a framing square, and measuring the height at the center of the square, and doing some basic math, couldn't find it on the wood magazine article index, any help?? Have a few pieces of curved base to make for the basement, and I somehow deleted my plans from the auto Cad program

Does this site help you?

 

Danl

That's what I needed Danl, now for the real question, how is it done? Can't remember, half the length×the height÷by 2xthe length or something on that order. Thanks for you reply, that will get me started Barry

 If you were to lay your framing square on the floor against the wall and the edge of the bookcase on both sides and continued that line out to where it intersects I would think that from that point to the front of the bookcase would give you your measurement for the radius. You could double check the center and two ends of the shelf to be accurate. Just a thought.

No math please it makes my head hurt (from a land surveyor's perspective), just determine where the begin of the curve starts, and the end, 90 off those points and intersect the line, measure the line off the wall to the intersection, you'll be close enough for the project requirements.

 

Lay a straight edge on the flat portion of the base of the wall, slide it back n forth up on the curve and back down to the flat portion, where the straight edge can lay completely flat on the wall before it hits the curve, that is your begin curve. And that is where you 90 off the wall, the same for the end of curve, once you have established the BC and EC, you can then 90 off the wall at those points, take a line off those points till they intersect, that is your radius point, measure from the rad point, back to the EC or BC or both, if they are dead on, great, if they are like 3' 5" on one side and 3' 6" on the other rad line, take a average, 3' 5 1/2" will be your radius.

 

Also, Kenny, is the radius too tight to kerf the base molding to make it more flexible?

Duck soup, the sides of case are parallel to each other, they would not intersect at the center point.

John Morris, here's the math lesson you didn't request.

I found the formula I was looking for, I like learning things, instead of punching numbers into a computer, but I have limitations when it comes to my thoughts. Using the site Danl posted, both methods come out with the same radius, and 48.75" does ring a bell. I will bend 3-1/4" boards to get the 3/4" thickness, as shown on the base of my bar. For you information using 1 9/16" height or 1.5625 instead of 1.5" it changes the radius by almost 2". Also, kerfing would not work, as I don't want to see the kerf marks, thanks for everyone's help. I also don't know why the 8 in 8xheight comes into play, but it is a number that does not change in Danl's post.

this is why i don't do curves.... gah!

 

Curves are very time consuming, yet very rewarding when done!

2 hours ago, Kenny Tarmack said:

John Morris, here's the math lesson you didn't request.

Kenny, I try to leave my math at work sorry for for being short sighted this morning, you asked for math, I went to carpenter layout, sorry about that.

Ok, based on your measurements shown, if I were at work, laying out a curb and gutter on the return, you know like where they build the wheel chair ramps into, and for discussions sake the only information I had on my plans to layout my curb return, was a "Mid Ordinate" as you show, I would use the following to find my radius:

 

      a2 + b2

R=-------------

         2 a

 

Given your measurements you came up with, a = mid ordinate as you show being 1.5", b = half the chord as you show being 12".

 

I get the same answer as you 48.75"

 

 

Thanks John Morris, I knew it wasn't as complicated as the formula I posted. Ralph posted something like this on his quiz at the other site, I think you have the easier formula and that's what I was looking for. By the way, where is Ralph??

45 minutes ago, Kenny Tarmack said:

Thanks John Morris, I knew it wasn't as complicated as the formula I posted. Ralph posted something like this on his quiz at the other site, I think you have the easier formula and that's what I was looking for. By the way, where is Ralph??

Hey, is Ralph posting quizzes on another site?

Haven't seen Ralph in awhile, he got really busy and I think we fell off the priority list, I hope he's well!

2 hours ago, John Morris said:

Hey, is Ralph posting quizzes on another site?

Haven't seen Ralph in awhile, he got really busy and I think we fell off the priority list, I hope he's well!

Was referring to the old "wood" forums

 Sorry @Kenny Tarmack, I missed the part about the baseboards thought the project was the bookcase.

 

 pretty much the same as @John Morris.

 

By the way, nice pics.

Bent the base today, three 6" boards resawed on the table saw, gives me 6 boards at 48" plus or minus( enough for the project) milled them down to 1/4" each and spread the glue, and clamped them up. Plenty of clamps on hand, I'll never run out of them clamps. I over bent them at a 47" radius, when they "relax" they'll fit just fine

Got the base cleaned up, clear coated and installed. I intentionally over bent it, 47" as opposed to the correct 48.75" radius. It relaxed perfectly when I unclamped it. 

Kenny, your finish product didn't show up on my radar, sorry for the late reply, this turned out great! I like how you over-bent too, that was really cool. This project turned out wonderful.