On Tue, 16 Mar 2010 10:18:11 +0000, you wrote: >On 16 March 2010 00:23, Steve Blackmore <[email protected]> wrote: > >>>The reason for the G18 was to make G2 and G3 work in other parts of the code. >>>G18 means canned-cycle movement in Y, so it is an error to use G18 and >>>a canned cycle with a lathe. >> >> Huhhh??? > >G83 includes both movement (in the specified plane) to a position and >then a drilling cycle. >If G18 is programmed then the initial movement is in the XZ plane >followed by a peck-drill movement in the Y axis. > >> Makes no sense whatsoever to program G17 when you are working in XZ >> plane? > >In some ways, no. But then "G17" only mentions the Y axis in the >documentation/description. It also indicates which axis is to be used >for the canned-cycle movement and a change to the description text >would fix the apparent nonsensicality. >With a lathe G83 could equally well be used for peck-drilling holes in >the end of the work with a drill in the toolpost (my current usage) >but it also seems very well suited to peck-parting work in which case >the movement would be in the X axis. >There needs to be some way to tell EMC which one you want, and >G17/18/19 do seem like the most compliant way to do that. > >One proposal that has occurred to me would be to add G18.1 and G18,3, >both mean that arcs are to be created in the XZ plane, with G18.1 >indicating canned-cycle movements in the X axis and G18.3 in the Z >(G18.2 would be movement in Y, perhaps a cut-off slide or drilling >head) >This proposal would mean that G81.3 could be programmed at the >beginning and then all conventional lathe-turning operations would >work as expected.
There should be no need whatsoever for all that added .1 stuff. Programming G17 G2 or G18 G2 should do the arc in the respective plain, end of story. Canned cycles should be treated similar. For example - Here's how Mach does peck drilling. For mill mode the retract plane is assumed to be perpendicular to the axis of the currently selected plane, ie Z for XY plane, Y for XZ plane and X for YZ plane. For Turn mode the R plane is assumed to be along the X axis unless you tell it otherwise. Retract plane direction can be overridden with G17, G18, G19. This code applies to turn, and is similar for mill with the addition of a Y parameter. 1) G83ZzzXxxRrrQqq The Q is peck distance, the R is retract distance, and Z and X are obvious. X is assumed to be zero if not on the line. If set, it will drill at that X, but be warned its a dual axis move to the X,Z start coordinate. 2) G83.1ZzzXxxRrrQqq This is a faster peck cycle, the drill will retract only the Q distance on each peck. You will end out at either R plane or the original starting point on the Z depending on the G98 or G99 in effect. G83ZzzXxx Rrr QqqG99 will end up at the original Z plane, G98 will end up at the retract R plane. This is true of both the high speed peck as well as the G83 R plane drill cycle.. G98 and G99 are canned cycle return modes, G99 will take you in the retract plane at the distance indicated after the R word, G98 will take you in the retract plane to the position you were in before the canned cycle started. Mach also supports G81 - plain drilling and G82 Drill with dwell. Steve Blackmore -- ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
