layout bolt hole question - clarification please

Your calculator is probably not RPN, and you are not using any parentheses.

Re-work the problem, and write down the interermediate steps as numbers. I think you will wind up with a very different answer.

The problem you are punching in on the calculator is a very different one than the one you want to solve.

Using Marv's formula for example,

(.5) (your chord) = (.5)(1.25) = .75 or thereabouts.

and sin [(.5)(120)] = sin60 = 0.866

So it would seem that R in this case is going to be something like .75/.866 according to that formula.

Jim

Jim

Ron I e-mailed you a bolt hole and trig. program.Just enter the number of holes then radius and the starting angle of first hole and it will give you the xand y locations. Tim

Shameless plug alert...

If you own a PalmOS handheld device, download the free trial of "Geo-Matic Complete for the PalmOS" from my website and calculate as many bolt circles (plus triangles, circular segments/sectors, rings and ring sectors, regular polygons, chamfers, fillets, parallelograms, etc) as you can in the next five days. Find it at

Carmine Castiglia ISOFits! - ISO 286 on your PalmOS handheld InfosystemsPro LLC PalmOS apps for engineers and machinists

I have been using geo-matic since the beta testing. While I don't use it every day, it is a handy application every time I do use it.

Thanks Jim & all, that got me going in the right direction. ron