Backlash

[joedirt]

Is it possible to check and fix backlash on a vtc16 myself or should I leave it up to the overpriced mazak techs?
Reason I ask is I have to slow all of my feedrates down from what the mazatrol generates or my sharp corners don't look so sharp.

[ajl6549]

Thats norm with very high feed rates. There is a g-code for correcting that. It's called exact stop check (I can't remember what it is, i'll check manual at work in a.m.). What happens is that one axis acctually starts moving before the other stops completly. What happens with exact stop check is the control does an inposion check before moving next axis. Also yes it is possible to chk/adj. backlash. Must write a prog. somthing like this...


G91 G1 F50. X-.01
X.01
X-.01
X.01
M30

Run in single blk., use .0001 res. indicator, after a "good zero" is found take reading. should just move btwn 0.0000 and .0100 on the indicator, if it over shoots zero there is too much compensation, lower value, if it falls short increase val. I should note you'll need a parameter manual so you'll know which to adj. Also note, this a farely complex proceedure and caution should be used.

[ajl6549]

I found it, it's G09 (non-modal) or G61 (modal)

[Beotch]

The G09 and G61 will work only for eia----G61.1(2D shape Comp) also will stop this rounding of sharp corners but only in eia and is a option on earlier Controls. This G61.1 function works on the mazatrol side if you set Parameter F72 to a 1 for shape correction. If this parameter is set to be on there is no Mcode to activate it--it's just always on. If you don't set that parameter It can also be turned on and off with M153/M154.

[joedirt]

I'm running a 1/8 chamfer tool 5000 rpm .010 per rev. and that's slowing things down from what mazatrol auto calculates.I wouldn't think that would be a too high a feed rate but I could be wrong. The machine is mid 90's so I probably shouldn't expect too much.

In the parameter manual here it shows F72 as invalid.

[Beotch]

I looked in one of my M32 manuals and it also says invalid--It might depend on what version M32(M32A, M32B). I know on the M32A You can get the 2D option(G61.1)--but I can't say that it will open the F72 parameter also. Your feed is roughly 50 IPM--if you slow the feed does the corner rounding get better? Look at E22 and E25. These should get it to judge a corner and slow the feed down when coming into the corner.