Help Please,
I have always used g41 or g42 in turning to get my angles and radii to come out to print. However I have purchached an older machine which does not have tool radius comp option.

I seem to remember in years past a formula or constant to add (or subtract) in x and z for an angle or radius to come out to print. Does anyone know the formula or trig or constant for diffrent tool nose radii??

It's not a simple formula to cover all cases because you have different touch off points on your tool depending on direction of machining and ID vs OD.

I approach it like I am programming the center of the tool on a line that is offset by the tool radius. Then shift the X and Z in the direction of your touch off point.

Hi. I just uploaded an Excel spreadsheet that calculates the compensations.
I hope it's correct!
Here's the link with the triangle that shows where the angle and the axis are. click here

This is great to have, thank you I do a lot of manual programing with out cutter comp. Do you have any help with how I can get it to work to go from a radius into a 45 degree angle? say a .031 tool nose into the angle

That's tricky. I did it once and it took me quite a while to figure out how to calculate the difference between a .016 and a .031 radius. I have to check in my notebook at work tomorrow. Maybe I can also create another Excel spreadsheet for that.

Funny thing happened yesterday at work. The thread relief had a big radius (twice the width of the grooving tool) and the programmer didn't rough the radius at all. So I accidentally calculated the required X-Values for a Z-movement into the radius correctly!
So the radius was R.1106 and it started at X.5336 and Z-.8734 and ended at X.7548 and Z-.984.
So with my .063 grooving insert I wanted to rough it in 2 steps. I added .055 in to the starting point in Z (.8734 + .055): Z-.9284
The X value I calculated like this:
I took the root of Square R (.1106) - Square Z value (.055) and subtracted that from R. Multiplied that by 2 and added it to the start point in X (.5336)