View Full Version : FG command question

04-19-2005, 10:04 AM
Late night I had the opportunity to use the FG command in the Shpobot software. It was an attempt to re-start a file at a point in the middle of the file. I had considerable difficulty because the bit would plunge to zero (table surface) when I entered the line number. I reviewed the command reference guide, but it does not address this question (the "Offset plunge from Z axis" is at the default 0 setting). Comments anyone?

04-19-2005, 10:31 AM
If you start at the line where you left off the machine then trys to go where you told it to (the depth of the cut on that line)You need to look at the file in editor and find the last line that the Z was up out of the material, usually a Jog command, and start from that line.

04-19-2005, 10:40 AM
Hello M Holm!

When using the FG command, I believe you should'nt have to set ANYTHING than the file name... which is the one you were using just before an event that cause you/the tool to stop.

So far, from my previous attempts on using this command, one have to be VERY careful when selecting the "GOTO" line; if this line has a Z value lower than the material surface, the tool will go to this value (and the X & y too)... if the line has a CC rather than a M# or a J#, than you get... suprised!... one have to choose a line BEFORE the line at which you stop (I believe you might refer to the noted line in the LOG file...?) and to choose a line in which the code will make the tool move/jog ABOVE the material (positive Z value; unless you zeroed the Z at the bottoom of the blank). This might not get you exactly bak to where you were but previously on the toolpath...

I think this part of SB3 could use some improvment; a command that would sound something like "RETURN TO CUT" after the tool has been stopped and maybe moved. When one would use this command, the tool would go back to where it was, return to the line of code about where it was, plunge back and continue the machining...
Having wrote this I'm not 100% sure how this could be programed... it's just what I observed on other CNC tools...

Hey Scott! COOL logo!

04-19-2005, 01:27 PM
Thanks for the comments.

I did select a "go to" line # that included a Z depth that was above the material surface. I even tried a "go to" line that was a TURN TABBING FUNCTION OFF command. In each case the bit plunged to zero - even as the program was seeking up to the line number.


04-19-2005, 02:38 PM
Hummm... strange...

04-19-2005, 02:59 PM
I have seen two instances on my ALpha with 3.4.1, where the Z zero changed when a file stopped. One stop was a keyboard spacebar, the other stop was a random event, cause unknown. Could the Z zero have shifted to cause your restart problem?


04-19-2005, 03:21 PM
M Holm,
if you can duplicate the problem, you could report your observations to support... which will sure help you or at least tell you more about the FG command...

04-19-2005, 10:35 PM
M Holm

I have had this same problem many times. What the Bot is actually doing is going back to the last line where it left off and it will go back to that -Z level from the previous line where you stopped.
If you select a line of code that is one line farther along than you did select - now when it goes back it will go back to a safe Z line.

04-19-2005, 10:53 PM
Hi Doug!

I plan to test your suggestion as soon as can (I'm curious too) but until... can you confirmed that it will work that way each time?
Do I get it right; if I stopped the tool at say line 19, then I should select line 20 to have it to work the way you wrote?... "returning to cut" at the correct location at "Safe Z height"?