Router Bit (Roundover) Issue

[thisismry]

I recently had a project that calls for roundovers in two sizes, 1/8” and 1/4”. I have the following bits: 1/8” bit is an Amana (56125) and the 1/4” is a Whiteside (1572). In the design phase, I added 1/8” and 1/4” fillets to the respective parts. In the manufacture phase, I imported the tools direct from the manufacturer's database so the tool settings and info should be accurate and okay. For the toolpath, I selected 2D contour and am using the bottom contour of the fillet as the selection. The 1/8” phase went well, but for some reason the 1/4” phase is not working/cutting properly. The cutter center seems to be too far from the workpiece and doesn’t make actual contact with the edge to cut the roundover. It just ends up running the toolpath without any contact/cutting. Again, both the 1/8” and 1/4” bits information were imported from their respective manufacturers directly into Fusion, so I’m not sure why the 1/8” worked properly but the 1/4” didn’t, when effectively the design/toolpath were both the same, just for different sized roundover bits.

Any insight would be greatly appreciated. Thanks.

[seth.madore]

Would you be able to share your Fusion file here?
File > Export > Save to local folder, return to thread and attach the .f3d/.f3z file in your reply.

[thisismry]

Will do. I will get that exported and uploaded tonight. Thank you for your reply!

[thisismry]

I've attached the project file.

[matty.fuller]

The Whiteside tool is defined as a Form Mill, and has the control point on the inferred circumference:

... whereas the Amana tool is defined as a Radius Mill with the control point on center:

To get the right outcome from the Whiteside tool with this guide contour, you're going to want to set Compensation to Off under the Passes tab, or a negative radial stock to leave of the tool radius.

[seth.madore]

Not too fond of the idea of setting Compensation to "Off", I think I would rather just spend the 1-2 minutes and define the tool as a proper Corner Rounding bit...

[matty.fuller]

Fair, I would probably do similar... our tooling manufacturers don't have libraries yet so I'm always configuring tools from scratch anyway. (wink wink nudge nudge Seco, Leitz/Onsrud, Sutton Tools)

I don't have much experience using roundover tools in Fusion so not sure what the pitfalls are, but when looking at it I did think using negative stock to leave and creeping up on the right offset is the way to go... that's what I would do on a table router, and it strikes me that surely those tools don't actually come to zero diameter at the point.

[thisismry]

@matty.fuller Ah noted. I did recognize that the Whiteside and Amana tools were defined differently in the Fusion library. This is my first time trying to utilize a roundover bit with the software so I wasn't too sure what was going on, but your explanation makes sense. 

What does the compensation on/off do? And why is that not the preferred method for you @seth.madore ? 

Can I also bother you two to elaborate on how to define the tool within Fusion to achieve the proper function/center?

Thanks in advance.