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Author Topic: Reversed Arcs in Front Post/G-code/Dolphin question  (Read 3001 times)

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Reversed Arcs in Front Post/G-code/Dolphin question
« on: December 26, 2014, 02:31:07 PM »
Been doing some Dolphin lathe CAM stuff lately and having trouble on internal turning cuts.  Here's the path I'm having trouble with as seen in Dolphin; it's a roughing cut:



Using the Mach3 diameter mode post, here's what I got at first:



After unchecking Reversed Arcs in Front Post, everything is perfect except the one little circle at the end of the 1st roughing pass that leaves a little gouge in the piece, line 270 I think.  Everything's fine after that.  Anybody have an idea why that happens?  I guess I can edit that line, change it to a G01 back out to the clearance point??  My G-code Kung-Fu is weak unfortunately.

Milton from Tennessee ya'll.

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Re: Reversed Arcs in Front Post/G-code/Dolphin question
« Reply #1 on: December 28, 2014, 01:23:31 PM »
Did you choose the tool to be opposite of what it is meant to be?
Cant recall exactly what has to be done in V10 but internal tools have to be chosen differently than your actual machine. I dont recall if it is simply the Front/Rear option or if it is the approach or if it is both, that you have to choose.

Hood
Re: Reversed Arcs in Front Post/G-code/Dolphin question
« Reply #2 on: December 28, 2014, 02:59:57 PM »
Actually I chose the tool as it should be for my machine, ie: front tool post, approach from the front.  I re-read your response to another of my posts a year or so back but since this job came out near-perfect with only the Reversed Arcs change, I didn't try reversing the tool direction in Dolphin.  I'm orf to go try that now....
Milton from Tennessee ya'll.
Re: Reversed Arcs in Front Post/G-code/Dolphin question
« Reply #3 on: December 29, 2014, 10:46:38 AM »
Well that was interesting.  Looks like front turret/rear approach works as it should (other than the random arc issue) on my machine.  I tried all the available combinations of turret locations, approach directions & even left & right-handed tools but all I got were some truly bizarre tool paths.  I tried each of the combinations, P/P'd them each with different file names and tried them all in Mach with the various combinations of different IJ modes and Reversed Arcs in Front post settings and no joy was had, just psychedelic tool paths.

I did find a little info on the web about a number of decimal places/round-off mismatch between CAD & Dolphin causing problems.  More stuff to research & try.:)
Milton from Tennessee ya'll.
Re: Reversed Arcs in Front Post/G-code/Dolphin question
« Reply #4 on: December 30, 2014, 11:35:03 AM »
Me again  Duhh, further research has shown that (as usual) most of my CAD (and consequently CAM) problems are self-induced. When I zoom in to a nano level, the junction of the quarter-elliptic arc and the straight line was not absolutely perfect. When I corrected it, all is at it should be...I think.  Time will tell. ;D
Milton from Tennessee ya'll.

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Re: Reversed Arcs in Front Post/G-code/Dolphin question
« Reply #5 on: December 31, 2014, 05:06:51 PM »
All part of the fun :D

Hood
Re: Reversed Arcs in Front Post/G-code/Dolphin question
« Reply #6 on: December 31, 2014, 05:22:30 PM »
All part of the fun :D
As my ol' fishin' buddy (rest his soul) used to say: "Well, that was real, and it was fun, it just wasn't REAL fun."
Milton from Tennessee ya'll.

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Re: Reversed Arcs in Front Post/G-code/Dolphin question
« Reply #7 on: January 01, 2015, 04:59:12 AM »
:D