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Re: Lathe G code program debug help needed
Posted: Wed Oct 07, 2020 11:48 am
by cncsnw
If a pair of equal and opposite moves do not get you back to where you started, then changing the turns ratio is not going to help.
You either have mechanical lost motion (e.g. backlash), or you have electronic lost motion (dropped steps, false steps, or unachievable accel/decel rates).
Re: Lathe G code program debug help needed
Posted: Wed Oct 07, 2020 1:26 pm
by adrewfis
First things first is to install the better limit switches and then get the turns ratio fairly close. After that I plan on doing the ballscrew compensation every .5" all the way down to my soft limits per the video Marty recommended in another thread as it compensates differences both toward the spindle and back toward the tailstock. And also will try the backlash settings I saw in Tech Bulletin 37 if all else fails.
Re: Lathe G code program debug help needed
Posted: Wed Oct 07, 2020 5:29 pm
by tblough
As CNCSNW pointed out, you have either mechanical or electrical issues and no amount of mapping is going to correct the problem. Mapping is for errors on the order of tenths.
Re: Lathe G code program debug help needed
Posted: Thu Oct 08, 2020 7:45 am
by adrewfis
I dialed it in last night and am well within tolerance. I believe the whole issue was first, putting 8 in/rev causing the X & Z axis to crash into hard stops several times and this ended up loosening the set screws. Since I was unaware of the loose set screws, this caused the near catastrophe turning down the hex part. Next the G99 code was in place in the MDI mode instead of G98. Once I tightened the set screws and used the G98 code, things worked just fine. I plan on putting locktight on the set screws and re-doing the limit switches by the weekend and obviously checking to make sure to use .001 in/rev NOT 8 or 10 IF I end up using it. Otherwise will stick with the in/min setting.
Re: Lathe G code program debug help needed
Posted: Thu Oct 08, 2020 11:03 am
by martyscncgarage
adrewfis wrote: ↑Thu Oct 08, 2020 7:45 am
I dialed it in last night and am well within tolerance. I believe the whole issue was first, putting 8 in/rev causing the X & Z axis to crash into hard stops several times and this ended up loosening the set screws. Since I was unaware of the loose set screws, this caused the near catastrophe turning down the hex part. Next the G99 code was in place in the MDI mode instead of G98. Once I tightened the set screws and used the G98 code, things worked just fine. I plan on putting locktight on the set screws and re-doing the limit switches by the weekend and obviously checking to make sure to use .001 in/rev NOT 8 or 10 IF I end up using it. Otherwise will stick with the in/min setting.
Great to hear your progress.
Let us know when fully resolved so we can mark this as resolved.
Marty