Need Help!- Can we offset 3D program?

[Maxz]

I run copy surface with point-to-point program (linear only) The machine always moves 3 axises all the time. Tool tip runs on actual surface (finished surface). The current program has been generated from cad/cam. Thus there is no compensate command (G41 and G42).

If I would like to change size of finished workpiece by offset all dimensions 0.5 mm (enlarge), can I JUST insert G41 (or G42) and G43. Then use D and H to offset the workpiece?
I plan to plus H and D by 0.5 mm

My workpiece is look like a mountain. The current program starts at base of mountain, move up to top of mountain, then climbs down to the other side of mountain.
please advise

Thank you.
Maxz

[samu]

unfortunatly it's not possible that way. 3D offset must be perpendicular to the surface so you need 3d compensation option cause it's not a constant offset in x-y and z but it changes continiously according to the surface.

[Beaker]

Hey, just use axis scaling. If your job is 100mm and you want it to be 0.5mm bigger then scaling factor is P1.005
100.5/100 =1.005

Not sure what control your using, on a Mits it's

G51 Xn Yn Zn Pn
G50 to cancel
XYZ = center coordinates
P = scaling factor
hope this helps
Fanuc uses G51 In Jn Kn Pn
G50 to cancel
Hope this helps

[kklaver]

I have only seen this used on the Heidenhain TNC530 Control, Software pack 2. You need your CAM system to output "vector" control info. NX xxxxx, NY xxxxxx NZ xxxxxx on each line along with the standard XYZ commands.

KK

1 LN X+31.737 Y+21.954 Z+33.165
NX+0.2637581 NY+0.0078922 NZ-0.8764339 F1000 M3

From their Manual:
3-D compensation without tool orientation
The TNC displaces the tool in the direction of the surface-normal
vectors by the sum of the delta values (tool table and TOOL CALL).
Example: Block format with surface-normal vectors
The feed rate F and miscellaneous function M can be entered and
changed in the Programming and Editing mode of operation.
The coordinates of the straight-line end point and the components of
the surface-normal vectors are to be defined by the CAD system.

1 LN X+31.737 Y+21.954 Z+33.165
NX+0.2637581 NY+0.0078922 NZ-0.8764339 F1000 M3

LN: Straight line with 3-D compensation
X, Y, Z: Compensated coordinates of the straight-line end point
NX, NY, NZ: Components of the surface-normal vector
F: Feed rate
M: Miscellaneous function