Question for Live ...

[mayhugh1]

Does the Sprutcam lathe roughing operation handle complex internal profiling with axial mounted tooling? I've tried internal profiling several times and Sprutcam always seems to get it wrong - usually incorrectly removing significant internal material from the part or plowing through the part in order to get at a the part's external profile. It seems as though it is misinterpreting the workpiece. It works OK on simple internal boring and internal boring with step diameters, but it doesn't seem to handle internal fillets or chamfered parts created in SolidWorks. The finishing operation also refuses to generate toolpaths anywhere around internal fillets and chamfers. I've noticed that none of the examples or tutorials actually address complex internal profiling and so perhaps it wasn't designed to do so? Thanks - Terry

[Live]

Hello, Terry.
Could you please attach a problem project. We will look at it.
Right now we are working on a new lathe contouring operation.
Hopefully it will be a powerful tool for a vast majority of turning tasks.
Anyway bugs should be fixed.

[mayhugh1]

Live,
Thanks for the reply. Here is a project that has some internal contouring. I ground a contouring tool and closely approximated it with a standard toolholder and insert - this is the reason for the 'skinny' looking tool. In this particular project the latest 7.1.2 version of Sprutcam seems to incorrectly bore a taper into the wall of the part. Breaking the operation into two smaller operations causes the tool to move through the part where it tries to remove maerial from the outside. The 7.1.1 version shows the workpiece incorrectly in the simulation as a taper and crashes the application when the simulation is launched - I'm not sure about any earlier SC7 versions. Even though the part has both interior and external detail I tried to model the part as two separate models- one for interior and one for exterior to try to get around the problem, but in every case Sprutcam seems to get it wrong (or else I am doing something very wrong.) I tried SC2007 as I have done such projects in that version in the past. However, somewhere along one of the SC7 installs, SC2007 has been affected and now will not run with SC7 present. - Terry

[Live]

Hello Terry,
I've played with your project, and suppose the problem is in the three things.

1. The turn generatrix of the part was calculated by SprutCAM with some defects. To workaround that, I've created the section of the geometry model and set it as the part.

2. Wrong leads. Since it's a boring operation you have to choose inversed leads (Parameters->Lead In/Lead Out-> Set <Approach> to 135 deg, <Retract> to 315 deg.) Set the <Approach from tool change point> to <Radial> as well.

3. In Parameters->Strategy set <Plunge> to <All>.

Btw, you can save those settings as default and use them for all boring operations.

Here is the modified project (SC Rev 7.1.3: http://download.sprutcam.com/downloa....3.40918rc.exe)

http://www.cnczone.com/forums/attach...1&d=1297082295

[mayhugh1]

Live,
Thanks very much for your speedy and helpful reply. I didn't want to upgrade my version of Sprutcam to a non-released version in order to read the project that you created, but I used your advice to re-create the section within Sprutcam using the 2D geometry tool; and that solved the problem. I suspected it was a familiar issue with Sprutcam not interpreting the revolved model correctly because when I have tried to select internal fillets or chamfers in other projects, Sprutcam would refuse and issue a message that 'the selected feature degenerates to nothing.'
Since my parts are all created with SolidWorks and imported in SolidWorks native format, you might want to alert the developers of this issue. I've sent bug reports about similar issues to technical support in the past but have never received any acknowledgements or seen any improvements. Again, thanks very much for your excellent support. - Terry

[Live]

Originally Posted by mayhugh1 Live, I suspected it was a familiar issue with Sprutcam not interpreting the revolved model correctly because when I have tried to select internal fillets or chamfers in other projects, Sprutcam would refuse and issue a message that 'the selected feature degenerates to nothing.'

Hello Terry,
SprutCAM recognizes turn generatrices pretty reliable, but when it fails you'd better use the <Section> button on the <3d Model> tab. It is much easier than using <2d geometry>.

Could you please attache a project, or a picture for this problem?

It seems to be there is some little misunderstanding by you.
As I know, SprutCAM generates the "'the selected feature degenerates to nothing" message mainly in a 2d contouring operation when you try to add a geometry in the job assignment which is placed in a perpendicular plane (e.g. a geometry is in the ZX plane, an operation is in the XY plane, you try add curves form the geometry into the job assignment, SprutCAM projects'em onto the XY plane and they generate to nothing. That's what it means).

[mayhugh1]

Live,
I originally tried to use the Section Tool in the project that I posted, but the small ledge in the internal wall does not show up as part of the section (perhaps this is one of the defects in the imported model?), so I abandoned that approach. It didn't occur to me to use the 2D geometry tool to re-trace the section and fill in the missing portion, which as you suggested, fixed the problem.
If I try to select that small ledge in the inner wall as a face in the project that I posted (as a part of the work assignment) then I get that message in the lathe roughing operation. I originally tried to fill in the various internal faces as the job assignment hoping it would solve the original problem but I received this message and couldn't select this ledge. Perhaps this is a clue as to why the solid of revolution isn't always properly interpreted? - Terry

[Live]

Originally Posted by mayhugh1 Live, I originally tried to use the Section Tool in the project that I posted, but the small ledge in the internal wall does not show up as part of the section

I think the reason of the problem was that the section plane was going directly along an edge, and SprutCAM has refused it by some reason. When I did my plane section, i've just rotated the plane by some angle and have checked the <Join curves> option.