View Full Version : Help on cutting a radius

03-18-2008, 11:29 PM
Hey Guys,
My brain isn't working and I need some help on how to cut a radius. I'm no good at drawing pictures so the two attached images is the best I can do but maybe they will help to fill in the gaps as I try to explain what I want to do.

I will be working with square stock that's 1" thick. I want to cut a "flat" at the end of stock. This flat is to be cut half way through the stock (1/2" deep cut) using a 1" dia cutter to full diameter. This flat is to mate with a second flat that looks exactly the same and bolted together via a center hold. Once the flat is cut, I want to radius the corners so they match the radius of the 1" dia cut. Obviously a deep radius-ed lip will remain. I have an 8" rotary table for the mill. How do I go about setting up the rotary table when cutting the radius so that when I rotate the table, it will cut a radius that will match the 1" circle? When finished, I want it to look like the top view (second image)?




03-18-2008, 11:43 PM
I've tried reading many times, and still can't quite relate your words to your drawings.

03-19-2008, 12:12 AM
What snowman said.

My head doesn't fit around it either.

03-19-2008, 12:22 AM
Let's approach it in the following way. Look at the first image. This represents a partially completed piece of work since there are corners on the block of "metal". Now look at the second image. This represents the finished product with rounded corners.

How do I cut the rounded corners from the block using a rotary table so that it resembles the finished product if viewed from looking down on the image?


03-19-2008, 12:34 AM
The center axis of your rotab has to be aligned with the center of the part radius. The spindle has to be aligned with the rotab so that they are concentric. Now move either x or y axis the radius of the part plus the radius of the cutter.

Make sense?

03-19-2008, 05:46 AM
Yes, that makes sense. Thanks for your reply.