Gene, If you open up Arc Buddy or Arc Generator if you have the latest one and enter some start and end angles and note the I and J for the arc in that quadrant.
From 0° to 270° in the CW direction I is -radius and J is 0. From 90° to 0° in the CW direction I is 0 and J is -radius From 180° to 90° in the CW direction Y+radius I is radius and J is 0. For example: G1 X start point Y start point G2 or 3 X end point Y end point I depends on quadrant and J depends on quadrant. So for example an arc from 180° to 90° with the center at X1 Y1 and a radius of 0.250 G1 or 0 X[center - radius] Y[center] G2 or 3 X[center] Y[center + radius] I[radius] J0 JT On 12/7/2014 8:46 AM, Gene Heskett wrote: > Greetings; > > According to the AXIS window title: > > Sim version of AXIS 2.7.0pre0-616-gcd4180d > > I have this board end carving routine almost working. > I can do a right end of y_top motion arc just fine. But while the > backplot looks perfect if I turn off the arc and just do a move from its > start point to its end point, giving me a (in the case that doesn't work) > a 45 degree line slanted to the correct ending position, where the arc > should end IF it was done. I have switches in the code to do the G2 line > or not > > Now, I have figured out how to get a copy/paste output I can show you, > from the screen I ran lcnc from if I force it to run despite the error. > > That error stanza is > > emc/task/emctask.cc 389: > interp_error: Radius to end of arc differs from radius to start: > start=(X-3.7600,Y-0.5630) > center=(X-3.7600,Y-0.4380) > end=(X-3.5100,Y-0.3130) > r1=0.1250 > r2=0.2795 > abs_err=0.1545 > rel_err=55.2786% > Radius to end of arc differs from radius to start: > start=(X-3.7600,Y-0.5630) > center=(X-3.7600,Y-0.4380) > end=(X-3.5100,Y-0.3130) > r1=0.1250 > r2=0.2795 > abs_err=0.1545 > rel_err=55.2786% > > And while I didn't double click the paste, I did reformat for a line per > value shown. > > To my understanding the one thing I note is the center value is off, it > s/b -3.635. The start end end points are correct. r2 seems bogus too. > > #<_tool_rad> below is .125 (1/4" mill. > The lines of code that generates that error are: > #<LlocalX> = [#<_x_tmp> + #<_tool_rad>](set position for arc target point) > #<_x_tmp> above is a step & repeat value from the caller. > > G1 Y#<_y_curve_pt> (place machine for up arc ) = -0.563 > > G2 X#<LlocalX> Y#<_y_start> J#<_tool_rad> > > I have now played 10,000 monkeys with J or I and sign of tool_rad. > > A Screenshot-2.png has been put in the lathe-stf link on my web page in my > sig, taken with that arc statement turned off. > > Can it even be seen whats wrong from the above? > > Cheers, Gene Heskett ------------------------------------------------------------------------------ Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from Actuate! Instantly Supercharge Your Business Reports and Dashboards with Interactivity, Sharing, Native Excel Exports, App Integration & more Get technology previously reserved for billion-dollar corporations, FREE http://pubads.g.doubleclick.net/gampad/clk?id=164703151&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
