Lathe CAM backside face axial grooving

[Anonymous]

Can anybody confirm if the lathe turning profile can cut an axial groove on the backside of a disk shaped part with slightly concaved sides?  It works on the right side (frontside) of the part as can be seen in my file.  However, with a LH turning tool I cannot get it to go into the backside concave of the disk.  Instead, it just cuts like it would had I selected the option to "not cut axial and radial grooves".  It does make the comment that the tool holder needs to be set up correctly but I think I do have it with plenty of tool clearance and a -5 degree orientation.  I have looked all over the forum and youtube for an example of this working but no luck. Attached is the file if anybody wants to give it a look.  

FYI, I do get it to remove the backside material with the turning groove job step using a grooving tool, but that is not the kind of tool or cutting direction I need.

[Anonymous]

red arrow points to stock left uncut

[alexander.patrushev]

It's a known issue of the turning profile when used a left-handed tool and back-to-front direction. We are preparing a general solution for this issue (see the attached picture) and other similar cutting limitations.

[Anonymous]

Thanks for the info, can't wait for the update.  Where should I have looked to see these kinds of known limitations?

As a side note, I discovered that if you turn off rest machining and enter a very small negative angle for Pass Direction (-1), it works!  So this is a workaround for now.

Cheers

[Anonymous]

It does not look like the May update 2.0.3125 addressed this problem.

[Anonymous]

A year later . . . is there any update on this?  The same problem still exists. 

Cheers

[angelo.juras]

Hello @Anonymous - I am looking into this and will get back to you.

[Anonymous]

ok, thanks.

[angelo.juras]

Hello @Anonymous - We took a look at the reported issue and created ticket CAM-10345 for our development team to look at.

[Anonymous]

Thanks, I can't wait.

[Anonymous]

Three years later . . . is there any update on this?  The same problem still exists. 

Cheers

[Anonymous]

I was able to get roughing done using new roughing strategy, however, finishing as derived strategy from roughing operation is not working too many problems.

I tried without holder which I suspected was reason for not being able to control back side limit within clearance provided by grooving tool. Moving back marker lets me extend cut in Z minus direction but not to bring it closer to back of the model.

Using sketch to drive tool results in error with weird explanation, sketch is projection of sectional view without any breaks in it.

Finally I used duplicate of roughing strategy with 1. deep step over and no stock to leave.

So, it is possible to generate tool path and edit out invalid part of resulting G-code but this is far from any productive and reliable result.

[akash.kamoolkar]

Like Vic said, the new roughing strategy removes the material correctly. I will make a ticket for the finishing.

Regards,

Akash Kamoolkar

[Anonymous]

with the new survey on lathe CAM there could be some interest in fixing this  

[akash.kamoolkar]

@Anonymous This seems to be working now in the latest release. If it still isn't, could you attach a sample file?

Thanks,

Akash Kamoolkar

[Anonymous]

The sample file is in the first post.  It has not changed.  It does not work.  Can you please post the sample file where you got it to work with either the rough or finish pass and while the pass direction is zero.

[Anonymous · Accepted solution]

Undercutting works, key seems to be in allowing both, radial and axial undercutting in operation.

I started with original file, suspended existing tool path and generated new roughing and finishing tool path.

There are some issues with grooving of back side, profiling tool is crashing into stock but i was only focusing on undercutting.

[Anonymous]

Thanks Vic, I see you are right.

The problem for me was that I did not know to delete an old job step and reselect it.  For back side turning the new rough and finish routines work, the old ones do not.  In the future it would be helpful if, when an old routine is  "sightlently" swapped out for a new one, that the old routines show a blue flag marking a newer version is available.

I wonder how many of my old CAM files are filled with outdated routines that should be updated.  How would one know?

Cheers

Dave

[Anonymous]

There is an interesting twist to it though, roughing works if I select "Allow axial grooving" or "Allow axial and radial grooving".

Finish profile only works if I select "Allow radial and axial grooving", so it is good to know that it works but the fact that it only works if both radial and axial grooving is selected, is misleading.

It's misleading because it should only require axial grooving, I don't expect it to work in any other way ,.... until it does.

Even though it works, having to activate radial grooving in order to perform axial grooving defies logic.

I got used to tinkering with options after updates just to see where it leads and on this one I see traces of some old bugs with finish profiling.

[Anonymous]

It works the way it does but we are still in uncharted waters in turning so experimenting is a must to uncover options, ..... or bugs.