[matt.huck]

Hi all,

I am trying to program a 4 axis part (A axis is perpendicular to the tool axis)

I have a round shaft and would like to cut a groove around it with complex curves ('snake' around the shaft).

I can't mill full tool diameter and so would like to create a single tool path for a small ball mill or engraving bit.

Have tried to use variable contour with streamline but can't select just the curve as a guide. Thought that maybe generic motion but can't find a follow curve type option for 4 axis.

Any ideas.

Thanks

Matt

[markrief]

I would start with Variable Axis Surface Contouring, Curve/Point drive method, project towards the centerline, with tool axis normal to the centerline.

[matt.huck]

I would start with Variable Axis Surface Contouring, Curve/Point drive method, project towards the centerline, with tool axis normal to the centerline.

Hi,

I think I have tried every combination of drive, projection and tool axis! I have attached the part file - I am wondering if there is something challenging about the part itself as I have had success with VC in other parts.

Any chance you could have a look at the part. Note - it is a 4 axis job, not capable of 5.

I actually just need a single pass toolpath that traces along the surface - a bit like a v-bit engraving path would be fine, I don't necessarily need to mill a square bottom pocket for this job. Saying that - I would love to be able to do that in future jobs so if you have any ideas what is wrong I would be very grateful.

Thanks

Matt

[markrief]

I attached a part with 2 surface contouring operations - curve/point and streamline.
The only think I changed OOTB was setting the tool axis away from line, to make sure the path is 4 axis..

The streamline is rough, but you will get the idea. If you create some cross curves along the way, it should be fine.
I added a little part stock to move the path away from the part so you can see it.

Note that the curves around the ring are not connected, so I suggest cleaning this up for the best results in CAM.

[1 Infinite Loop]

Here is something that might help you in the future. From the NX doc on Projection Vector Recommendations...


Tool Axis or Specify Vector

Use these options for cases where the vector will not be parallel to the targeted surfaces.



Away from Point, Toward Point, and Away from Line, Toward Line

Use these options for cases where you have a combination of surfaces where a single vector will not be at a sufficient angle for all the surfaces.

Make sure that the point or line you choose is located so that the cutter can reach the entire area to cut when projected from or towards the specified point or line. When using away, make sure the tool does not gouge the part when its tip is located on the point or line. Use Away from Point or Away from Line when machining a cavity. Use Toward Point or Toward Line when machining a core.

These options do not rely on the drive surface normals, and are robust for handling parts where the tool radius is larger than the part features (fillet radii, corners, and so on).




Normal to Drive and Toward Drive

Use these options for cases where the normals to the drive surface are well defined and change very smoothly. Use Toward Drive to machine cavities, and Normal to Drive to machine cores.

They may not be robust in some cases where the tool radius is larger than the part features (fillet radii, corners, and so on).

[matt.huck]

I am really sorry - I must have come across as ungrateful.

My emails didn't give me the notification of your answer and I have just come back to the site and saw that you helped!!!

Much appreciated - that is perfect to explain. I will experiment tonight.

Again - sorry for not responding, it is always rude when you go out of your way to help someone and they don't even say thanks.

Matt

[markrief]

No problem Matt.
Be sure to download the part (ring.zip) I posted last month.