3D Fillet Contour Machining HELP!

[ruga666]

Hello, I am working on a sign and I put a radius corner on the perimeter of the part. I can't for the life of me get a clean pass around the perimeter of the fillet on the edge of the sign. I tried a three different toolpaths, 3D contour, Ramp, and 3D Pocket all unsuccessful at creating a nice smooth finish. They are doing some strange things and I am not sure why. it seems like a very simple 3D toolpath, but every toolpath I try seems to jump around the sign and do strange things. I'm using a 1/4" Ball Nose bit. Here is a link to the file  https://a360.co/2JZUtpk Thanks 

Sean 

[kellings · Accepted solution]

Have a look at the attached and let me know if this is what you are looking for. If it is, i'll explain more about what I did. (note, I deleted all the other tool paths just so you could be sure which one I changed)

Kevin

[ruga666]

Here is a picture of the Ramp toolpath that was the closest to working properly. Again it jumps around, and goes down way waste the fillet on some areas. Not sure why 

[ruga666]

Yes Kevin, that is EXACTLY what I was trying to do. What did you do differently than me? Thank you very much. 

[kellings · Accepted solution]

On the Geometry tab, go to the additional offset page and type in -tolerance . You could also type in -.0004 but if you use -tolerance, the value will update if you change the tolerance on the Passes tab. The other change I made was to check the box for Contact Point Boundary 

I got an even cleaner toolpath by reducing the tolerance on the passes tab from .0004" to .0001". So you can give that a try too. 

Can you please mark my answer as a solution? 

Thanks,

Kevin

[ruga666]

I see that that worked for the part. But I don't understand how plugging in a negative offset in the toolpath would make it do the right thing? I would think the opposite, that you would add a slight offset so the tool would go past the radius??

[ruga666]

Especially with such a small number. How could -.0004 make a difference and make the toolpath do the right thing I'm not understanding that. 

[ruga666]

Also, to select the edges of the part we used a boundaries to get the toolpath to where we wanted it to go. Is there a way to just click the face/surface of the curve and get the program to recognize that instead?? 

[kellings]

Currently there is no way to just select the faces, instead for something like this you have to define the boundaries for the toolpath. 

Here is a YouTube video that I did that explains what is going on and why entering those values works. 

https://youtu.be/93oCFMCqQZg

Search for Rob Lockwood on YouTube as well. That guy has forgotten more about Fusion toolpaths than I will probably ever know!

Kevin