Machining large chamfers with a bull nose endmill

[wayneccomeaux522]

I have exhausted all of the different options I have available to me and I can't seem to figure out how to exclusively machine this angled surface with a back and forth machine path starting at the bottom and going to the top. Anyone familiar with GibbsCAM would know about the morph between two curves option. This allows you to create a path ON a surface between two curves (these curves can be open or closed). I'm trying to emulate that exact same path in Fusion360 to eliminate extra air passes and unneeded rapid moves when all I'm trying to do is work my way from the bottom of a chamfer up to the top.

Edit: Added an image for clarity.

EDIT 2:

Using "Ramp" is the closest I could get to my desired toolpath. As you can see it wraps around the side of the solid and always rapids up and over to the start instead of just chaining to each new path. I tried different lead-in strategies and the only one that came close to what I want was effectively a feed-rate rapid with "smooth profile" where I couldn't control the feed or step up.

[programming2C78B]

Why not a Parallel path, bottom is the [bottom vertex -(tool rad)], select the cut direction and maybe apply a 180 so it starts at the bottom. Contact point boundary. 

[engineguy · Accepted solution]

@wayneccomeaux522 

What you describe sounds exactly like the "3D Blend" toolpath, this is done by selecting the "Surface" to be machined to and two "Drive Curves" either side of the surface, if you don`t see this toolpath in the list of 3D toolpaths then it may not have been enabled in your preferences, see image below, hope this helps 🙂

[j.mitch97]

This is what I would use and recommend

[engineguy]

@wayneccomeaux522 

Have a look at the image below, I think that this is what you are looking for,  I have done a small example file for you to look at the settings, just open the Fusion file and run the Simulation first and if it what you want then delve into the settings 🙂 🙂 🙂

Image above gets you image below using the "Blend" Toolpath 🙂

[wayneccomeaux522]

This gets me extremely close to where I want to be. Unfortunately I don't see a way to extend off of the surface (to prevent crashing) anywhere in the settings for Blend so I'm going to have to cheat it with another surface which is fine. Thanks a ton for the tip... ill be using this strategy A LOT.

[hunt_fred]

Flow is a pretty useful toolpath for making chamfers with a bullnose.  You can extend the surface by "extending the tangential fragment" on the passes tab.

[wayneccomeaux522]

I definitely played with flow for around 20 minutes and couldn't get a cut strategy that looked even remotely close to that. Maybe I'll play around with it some more today to see if I can get something more concrete... thanks!

Edit: I was able to get the path, but the issue was not being able to control the direction of the approach. I'd like to machine bottom up instead of top to bottom. Seems like there isn't a way to control that unless you can click the red arrows?

[hunt_fred]

You do have minimal control of the approach using the "Entry Position" on the linking tab. By picking a point on the side you want to start on, it will begin the path from that side. The Flow toolpath is very useful, but it has some weaknesses. It doesn't do well with complex surfaces since it is limited to only UV directions on the surface. It only does individual surfaces, it does not blend multiple surfaces into one continuous toolpath. The lead-in lead out is missing. There is no check surface option. And the picking the number of stepovers is archaic vs picking a stepover distance (major issue if you are picking multiple surfaces of different size). In your example, however, it is the ideal toolpath.