Suggestion for Milling Thread, Bore, Circular Operations: Override Cutting Feedrate with Adjusted Feedrate for Circular Interpolation

[raymus.houston]

I recently came across this information when I was looking up feeds and speeds for threadmilling on Harvey Tool's site. This is an issue that affects threadmilling as well as circle/bore milling, especially when milling internal hole features using tools with a diameter only a bit smaller than the diameter of a hole or the major diameter of a thread: if you just use a standard feedrate on circular features (internal & external: holes, threads, round bosses and even radii in a contour), the effective feedrate is actually different than the commanded feedrate. This can result in terrible chatter, small out-of-round holes, & possibly short lived or broken tools depending on how significant the difference is.

There is a simple formula to adjust the recommended feedrate to the adjusted circular feedrate depending on feature Ø & cutter Ø, which I use to manually enter into the cutting feedrate parameter. Then I tried creating an expression to handle this, which works rather well in the operations that require circular or cylindrical face selections like milling thread, bore, & circular, since I can use the holeTopDiameter variable along with the tool_diameter variable for any pairing of circle Ø with tool Ø.

However, I think implementing this as a feature of the operation dialogue to be able to override the tool's cutting feedrate quickly and easily would be a valuable addition to the 3 cylindrical face driven operations.

If there was also any way to implement it to work with feed optimization at radii in contouring operations and helical ramping in pocketing or adaptive strategies, I think that would also help to significantly improve the experience and the results of programming with Fusion 360.

Links to useful information on this subject:

Haas Tip of the Day - Your Feedrate is Wrong!

Harvey Tool Technical Resource - Running in Circles

[camcompco]

I would like to see this as well.  It would be, yet another, step towards Fusion360 joining the ranks of a world-class offering.

[Sq_14]

Don't hold your breath over this.

I asked for this quite some time ago, and I sure wasn't the first to bring this to attention.

[a.laasW8M6T]

Yea it would be pretty handy, i have to constantly adjust feeds when it should be a press of a button.

Like a checkbox called Adjust circular feed.

I could modify my post to add M109(Heidenhain, will adjust the feed in the control) to those operations but that requires using in control compensation which i pretty much never use.

[possamai.cadcam]

It is necessary for all this operations you mentioned and also on profile milling. 

Right now the Feed Adjustment is pretty buggy and it should adjust the feed depending on the inner radius being machined, not a fixed feed as it is now.

Just like Featurecam or NX.

[programming2C78B]

You can easily make a formula to do this for you, then just save that resulted feed in your threadmill tool library for its feeds and speeds.

[Sq_14]

Sorry, but how could one automatically retrieve the hole diameter from the model and use the value as a variable in the tool library or just what would make even more sense, in calculating speeds and feeds within  the operation.

[programming2C78B]

You dont, this is just something you do when you use a tool in a hole less than 1.5x it's diameter. For threadmills, they will most likely always be used just for one hole size (like in my example, for 5mm threads).

[Sq_14]

I wager the guess, you missed the point of the thread