Milling diameters with 4th Axis

[erikhardy339]

Hi ! 

I am new to 4th axis machining, so bare with me! 

I am attempting to rough and mill a part out that I wish I had a lathe for. I'm working with a Haas VF2 and HRT-210 4th axis. 

What is the appropriate method for roughing and finishing diameters using a 4th axis? Is there a way to hold the spindle stationary while the rotary table is spinning to cut accurate diameters? 

I've attempted to use a Rotary toolpath which appears to be 90% of the solution. The faces adjacent to the undercut are important and need to meet the spec. 

I am attempting a similar process towards the video below. 
https://www.youtube.com/watch?v=81UjjSH2iFw&t=354s

Erik

[a.laasW8M6T]

Someone else may chime in but this is kind of tricky to do with fusion but very easy to program at the machine longhand. I'm not super familiar with Haas and Gcode for milling but that how I would program it.

Just program the cutter to approach in Z to the diameter you want and then program G01 A360, you could repeat this at both ends to clean up the walls.

Unfortunately your not going to ever get quite perfect geometry using an endmill due to the dished relief in the end of the cutter and also the way the endmill generates the geometry as the 4th rotates.

That WFL video is only really demonstrating milling these features for roughing, in reality they need to be finished by turning or grinding.

[erikhardy339]

Thanks for the reply! 

I ended up going down the rabbit hole hole of mill-turning the parts, with the raw material chucked into the spindle. 

I am still exploring how I can better use the rotary table and F360. I'm not very comfortable programming the machine by hand, it gives me a lot of nerves! There is a similar scenario if I am working on a round part chucked into the rotary table that I need to put a long chamfer on the end of it. It's a simple cut as you stated by hand with a 90 degree endmill, but I cannot figure out how to trick F360 to do it.