On Monday 28 May 2018 06:34:13 Marcus Bowman wrote: > Gene, > > Knowing you have more experience of tricky tasks than I have, and > seeing not much response to your question, I offer the following > observations: > > I have forgotten the exact reason you are dealing, in places, with the > locations of the co-ordinate systems (#5222 etc), but my inclination > is always to avoid this, where possible, by using G92, or G10 L20 or > similar. > I am saveing #5222 in a fixed named var, and referencing the map move of the y with an g10 l2 p y[<_tmpy> + #<_y_reset>] where tmpy is the variable but must be made inches before letting the D10 L2 p1 anywhere near it.
Then at the end, restoring #5222 from #<_y_reset> And if I have to interrupt it, an #5222=#<_y_reset> in the mdi window puts it all back to square one. I'd post the code, but there is one mistake at the end I want to fix, and I want to incorporate an automatic tool length measurement, the lack of which has caused some oops marks on the hats, and crushed 3 or 4 tools. I'd like to get it down to measure the shank OD and find the exact or a couple thou bigger drill, install it in the chuck mounted on the table, drive it to x0y0 as its touched off to be centered on the drill, bore the thru hole with a very gentle start so the bolt hole coming it from the side for the keying cap screw doesn't pull it too far off, then once its past the center drill cut, crank up the feed and go down till no more brass comes out. Raise it 150 mills, remove the r8, poke the brass slug out of it and transfer it to the rotating jig's r8, measure the stub to see how big a grub screw to use, find a tap drill for that sized screw, change code to switch in the drill routine. I was cutting a small flat on the sides so the drill didn't walk, but a sharp drill at slow feed for the first mm solves that. Then switch the feed rate up to 40mm until the drill is about to start a whole plumb thru, pull it back out, turn the table 90 degrees and repeat till its 270. Drilling done, change the vars that select drill or tap and tell it what the tpmm of this tap is, put the tap in the spindle, use a g38.2 to measure its length so I can put the tap tip in the hole, then peck tap to around 11 or 12mm from that measured tap length. But the tap routine has a small retract while the table is turning, and of coarse I rezero the table for the first hole by running it back to -10, then fwd to zero so all table moves are against the same side of the worm, its factory equiped with about 3 degrees of backlash. It can be adjusted but the bull gear has 2 or 3 thou of eccentricity, so you leave it loose enough the motor can drive it. Never, ever, buy a table made in India. POS. > I try to use named variables for any parameters which will have to > change when I next run or edit the program. I use a lot of subroutines > and pre-prepared program fragments, so my work cycle often looks like: > load a pre-prepared program or subroutine; edit it to change speeds, > sizes or whatever; then save. Reload the program and run it. With that > kind of cycle, I need everything that could possibly change to be in a > block of parameters at the start. I do this even with programs > generated by post-processors (like the Vectric programs). I edit the > program to define speeds using parameters, for example, so that I can > experiment quickly with different materials. I make the guts of whole > pograms into subroutines, etc. It doesn't take long to do, but > frequently repays the effort. > > I often use subroutines which begin with G92 X0 Y0; do something > centred on the (temporary) X0 Y0; then end with G92.1 I also keep > track of X and Y throughout, by using named parameters and use > parameters as counters for currentDepth, currentX, etc. That way, I > seldom know what the actual co-ordinate value is, but mostly don't > need to. > > I can't imagine rewriting the P1 map. I have done it, but can't > imagine why it would be necessary in reality. > > I'm being a bit provocative, here, but hope the above might help > stimulate a line of thought which might help. Apologies if it seems > like asking you to suck eggs. It's not meant that way. It is meant to > push your thinking sideways. Which it needs from time to time. Another item I'll mention, I've bought a couple more sets of metric er-20 collets. And they are slit in an 8 slot pattern. And they can, by putting the taps stub corners in the slots, absolutely drive a tap with no slippage. They are only grabbing it by the square, so there is room for some tip eccentricity, but its 90% gone after the first hole is tapped. Being able to do that is pure serendipity. These 2 kits came with a much simplified TTS holder without the depth stop ring, and a frosted finish on the longer shank, AND THEY DON"T SPIN IN THE R8!. I'd assume its something to do with the frosted shank. > Marcus I appreciate the input Marcus, as there is often a better way that just never crosses my mind. Some would call it a one track mind. Using G92, it would be sensible to do a G92 X0 Y#<_offset> to move the cut incrementally. And its something that never crossed my aged wet ram. :) So thanks, I needed that. :) -- Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
