MDT flow wires to program cnc 3d

[wjbzone]

Has anyone tried this?

1. Draw with autocad solids.

2. Use MDT to convert a solid face to a surface

3. Use MDT to create flow-wires offset from the surface (by the radius of the ball end mill you intend to use)

4. connect the flow wires

5. export the point data of the 3dpoly line and use for a cnc program.

I have some nice shapes programmed with this method.

Bill

[wjbzone]

Here are some more details of the commands to create 3d gcode program from Autocad/MDT:

1. Draw in solids or surfaces in Autocad 2000 (or MDT).

2. Open drawing from MDT 5

3. Convert the portion of the solid to machine into a surface
toolbar -zfly-solid-surface -convert-faces (_am2sf)

4. If more than one surface is needed, join with:
toolbar -zfly-edit surface -join surface (_amjoinsf)

5. create flow wires offset from the surface by the ball end mill radius.
Toolbar – zfly-wire off surfaces – flow wires (_amflow)
Experiment with direction (U or V) and number of lines.
(check save in the dialogue box)

6. Group – explode – all wires.

7. Reverse direction of wires. (as necessary)
toolbar - zfly-edit wires -wire direction (_amwiredirection)
(alternate direction every other wire for best efficiency)

8. join wires
toolbar –zfly-edit wires –join wires (_amjoin3d)

8 (optional) Join the wires using toolpac (dotsoft.com)
Toolpac – polyline – maintaince –3dpoly – join segments
(may have to use Toolpac – Object – Modify – UCS Fix Parallel)

At this point you have a toolpath of the CENTER of the ball end mill that can be converted to G-code by:

1. Using a autocad to CAM add-in like Tahlcam
or
2. toolpac – utility – point export (to a text file)
(using a format mask -> <X[X]Y[Y]Z[Z]>)
or
3. Edit the text file (add a G1 and Feed as necessary)


To convert listed 3dpoly line to Gcode.
1. copy and paste list (in text window) into column B of Excel spread sheet.
2. Number column A sequentially
3. Sort columns A and B by column B
4. Delete all rows except those starting with “at point”:
( at point, X= -6.5316 Y= -0.9706 Z= 0.0667)
5. Re-sort both columns by Column A to get into original order
6. Copy and past into Word (text editor) – Paste special – text only
7. Replace all “at point, X= “ with “X”
8. Replace all “Y= “ with “Y”
9. Replace all “Z= “ with “Z”
10. Add G1 and feeds