Programming a reversed cone

[rickcact1]

Which toolpath do I use to cut a undercut cone. The cone shape is 1/4 degree bigger at the bottom of the cone. I will be using a lollipop style cutter.

 

Thanks,

Rick

[Chris_C]

Surface Finish Contour or Flowline are the only 2 (that I know of) that will work for undercuts...

[rickcact1]

Thank you for the response. It helps if I have a tool defined as a lollipop cutter and not a bullnose. DUH!!!!

 

Rick

[djstedman]

If I had to do this.. and it was one cone.. and not something that was showing up slightly different every other day.. I would just make a bunch of circles on on top of the other with the difference in height between them being whatever you wanted your stepover for a good finish..

 

Basically draw a vertical line to act as an axis .. then on a new level make a series of points using segment and number to space the points out along your axis..

 

Next draw a line at the desired angle.. and offset it in 1/2 your radius of your tool then segment it with the same number of points..

 

Then create circles using the points for center points and the angled line points for size..

 

Once that's done.. just toolpath the circles as a basic 2d contour and use your entry and exit to make sure you stay in the center and wont hit coming down through whatever hole your coming down through..

 

Sure this method is kind of labor intensive but.. it allows for absolute control of what you want.. which is something you wont get to easily using a surfacing path on an undercut surface..

 

Kind of a pain but a few minutes of messing with it and you can have something that does exactly what you want with no surprises .. then again someone might have a much easier way ..

[mike93]

that sounds like a long way to surf fin contour

[Chris Rizzo]

Two toolpaths support undercuts:

 

Surface fin (or rough) contour.

 

Flowline.

edit whoops sorry someone said the above ^^^^

 

Contour is generally my pref, you can get fantastic lead in/out with each z pass.

[Oscar R.]

I like using Flowline. You spiral the toolpath from the top down or bottom up and use the "Direction" settings to control your lead/lead out.

[Roger Peterson]

surface rough pocket will also support undercuts.

 

This is nice for roughing purposes so your finish tool engages a consistent amount of stock as it finishes.

 

You can also use it to finish, just "uncheck" roughing. Now you can do "Finish Passes" that support lead in/lead out, cutter comp, a plunge point, etc...

 

 

HTH