How to machine an open path?

I have a part I’m trying to make, a mount for a ball nut. I have a piece of stock about 1" thick by 1.25" wide and it’s maybe 10" long. Mounted in my vise with one end hanging out of the vise, I want to take a 1/2" endmill and just go down one side, around the curve on the end and back down the backside. This is an open path… I can draw the part with a closed path, but then it moves at a feed speed all around the part, cutting air over half the time and will take forever.

I re-drew the part with an open path, imported it and went to contour it, I thought I had it figured, actually got a path, but it’s on the inside of the part rather than the outside, have tried changing “offset open path” and a few other things and am not making any progress.

I have attached the job file…

ooops, added the attachment twice

Hi Brian,

doubleclick your operation - in the upcoming dialog select the tab cut path and there select ’ offset open paths ‘.
This will offset your operation by the tool radius.
And if you need you can click ’ climb cut’ .
Then click ok to close the contour dialog .

Now you have to move the startpoint of your operation ( the small S1 you can see at the beginning of your contour bottom right ) to the beginning of your contour at the top right by selecting the button with the ’ S ’ in the menu and move the mouse to the beginning of the line top right.
The S1 will jump there
In the simulation you can try your code.


Richard, thank you! I tried everything but moving my start point, which seems weird as it still starts at the bottom like I wanted, but it did move the end mill to the outside offset. It also rapids up and across the top of the part to get to the other side… this will save quite a bit of machine time, thanks again.