First, let me say… With the move speed set slow and the router/spindle off, I’m perfectly comfortable leaning over the machine to closely watch where the bit is. I feel certain that you will too, eventually! That said, this exercise in toolpath editing is not wasted time, you need to get familiar with doing it anyway! Some things I routinely edit the path for are:
- Change the end point so that router and bit is clear of the project.
- Add a “Goto” statement to rerun the file after a pause to change blanks
- Manually change speed settings when you discover some tweaking is in order
- Call another file when doing step and repeat.
Any text editor can be used to edit the toolpath file, but a good one is normally installed with SB3. It’s located under [F]ile --> part file [E]dit.
Some reading is in order to fully appreciate the power of the OpenSBP Language.
http://shopbottools.com/ShopBotDocs/...rogHandWin.pdf
and
http://shopbottools.com/ShopBotDocs/...mmandRefV3.pdf
As stated earlier, the purpose of this exercise is to create a toolpath that can test the location of key points of a file to be sure they fall within the perimeter of an irregular shaped substrate… In the past others have “air cut” entire files to determine this same information. By testing just key points, we can shorten the run time needed to determine this information!
Step one:
Determine what the key points are. Draw straight lines between these points. By not using curved lines we simplify determining Which points in our toolpath file are the ones of interest!
Step two:
Create a toolpath of our line that goes through the points of interest. Create it with zero depth of cut. Save the toolpath.
Step 3:
Open the toolpath created above with the text editor.
In my example, it’s easy to find the lines of code that move the machine to the desired test points… they are the only lines that have a Z value of 0.000000, also, they have “M” (move) commands in front of them. The “J” commands are jog moves.
Every toolpath file has a “PAUSE 2” command line in it… it is after the router/spindle “turn on” command and gives the router 2 seconds to come up to speed. This same command, without a parameter (like the 2) can be used to halt the program anywhere and not continue until given the ok by the user. To get the machine to stop at each test point, we manually enter the “PAUSE” command between each program line with the test point locations.
The “continue?” window is the default user interface in this situation.
Save the file with the changes.
Step 4:
Zero XY&Z on your machine.
Now re zero Z a known distance above the material, like .1”… this makes it easy to re-zero back to true zero after running the testpath.
Run the modified file… remember, air cutting is done without the router/spindle on! The bot will move to the first test point and stop… it will wait until you tell it to continue, to go to the next point. Continue through all test points until the file is complete.
Don’t forget to return to material zero before you run the part…
SG