I have a obscured angle in lathe, have any one can help me with this problem.

[Anonymous]

[akash.kamoolkar]

Can you attach your sample file here?

Regards,

Akash Kamoolkar

[Anonymous]

[Anonymous]

i used the left hand tool for the rest side but it is not work. thank you so much.

[Anonymous]

I messed with this for hours trying to figure out what if anything can produce acceptable result so here are few observations.

Roughing using new strategies does not work, using OD turning tool generates crash when strait holder encounters round model.

There is no way possible to modify square holder thickness to provide clearance.

I then used boring bar inverted 180 degrees to substitute for lock of ability to modify OD holder in Fusion.

In either case roughing is not completed, adjusting inner radius height is ignored and at the end of tool path, tool retracts strait up thru the model.

The only way possible is to use multiple finish profiling passes.

Defining insert orientation is not possible without use of holder and it should be, in real world holders are modified for radial clearance and used in a way they were not designed to be used because making face undercuts using profiling tools is very common task.

If insert orientation is tied to holder, user needs to be able to customize holder to any shape that allows creation of tool path.

It is up to user to see that desired result actually matches physical configuration of modified holder.

In multiple finish passes, it only works with "Back to front" cut direction selection which doesn't quite match resulting tool path direction of cut.

Trying to use old roughing strategy produced errors like ..... "multiple contours are not close enough to be joined" and "internal CAM kernel error", I could not produce tool path using model or sketch and error messages don't provide any clue as to what caused them.

My favorite is ..... "Tool path generated successfully in ??? seconds? , followed by ........... "Empty tool path".

[Anonymous · Accepted solution]

i make the same set up on fusion 360 and it worked. i use a custom tool with out holder, orientation is 210deg with left hand and -30 deg with right hand

[Anonymous]

That's interesting and I wanna point out what I mean, from perspective of machinist with enough experience to know what method is most appropriate for the task,......... I would never choose to drive that tool in horizontal direction.

What happens when you do that is that narrow insert tip is driven into solid stock, chips deprive cutting tip of coolant supply, tip overheats and thermal breakdown occurs as a result.

If you take a cut deeper then tip radius, stock will curl over insert and completely shut coolant supply, you will have melted insert tip in matter of seconds on steel for instance. 

Ideally, you want to drive the tool in vertical direction, opening the cavity across entire width with every pass.

Taking light passes, chips fall behind the insert while stream of coolant is on cutting tip and helps push chips out.

From that perspective, Fusion has not delivered solution in my trial, in fact, any task involving face undercutting has been a huge annoyance and impairment in Fusion for a long time.

Choosing arbitrary angle for insert orientation is not exactly solution either, it is true that you can mount OD tool holder slightly out of alignment with turret slot but that has limits.

I have few standard holders with 3 degrees face clearance, 3 degrees OD or ID clearance and 27.5 degrees on both sides of insert, some boring bars have 10 degrees face clearance, that restricts me to using options in sink with those spec's.

Coordination between Fusion and actual tool setup in machine is essential if you are going to trust anything you see in Fusion simulation.

When I use custom holder and assign front and back angles that match those of holder I can buy from tool distributor, insert is tied to that arrangement in Fusion, if I then disable custom holder, insert loses orientation that was obtained while using holder. 

In my example, it was not possible to use standard OD holder because it does not have radial relief to clear model, but my custom boring bar does.

Producing tool path of any possible configuration is not solution for me, producing one that is in sink with the way I intend to mount standard or somewhat modified tool and drive it in direction that benefits the task and preserves the tool proved out to be failure in my test.

When I say "somewhat" modified tool, I am referring to hand grinding radial relief to part of the holder entering radial undercut on face of the model.

One other modification would be milling shank so that it changes original angle of insert when shank is seated in slot of a turret.

Once you make such modifications to tool shank, you can program tool paths within the parameters of those changes, idea is to be able to detect potential crash before you "friction weld" tool to your work piece and you do that by defining parameters, simulating tool paths and finally matching that tool orientation in machine.

I can destroy insert tip on aluminum or remove fair amount of super alloy stock with no significant damage to cutting tip, depending on type of techniques employed, surface speed, DOC, coolant type and feed rate.

If you are making part out of wood, your margin of error would swallow many imperfections as compared to cutting metal so I am content with your conclusion but problem has no solution in my field of work,........  too many obstacles in making simple tool path that can be done in $150, pathetic piece of software such as Inplot using repeated offset passes or single pass in G73 cycle to rough, followed by G70 to finish, although I have better options at my disposal.

And finally, if you wonder why no one touched this thread in a month, I'd say it's because there is no easy solution with old or new turning strategies that qualify as effective, routinely done and reliable, getting lucky by selecting one variable that works out 10 that don't is not very productive.