Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Fred_evans on February 08, 2019, 04:47:17 AM

Title: homing sequence (G28)
Post by: Fred_evans on February 08, 2019, 04:47:17 AM

Hello All
I am using mach3 on my lathe
when I  call G28  to home - the machine homes the in a straight line to the
home position
I need it to home the x axis first ( taking the tool away from the stocK) and thereafter
to home the z axis
What is the code to do this?
regards fred
 

Title: Re: homing sequence (G28)
Post by: RICH on February 08, 2019, 05:29:57 AM

Fred,
G28 X ..... Z..... axis will move via an the intermediate point. When you don't specify an intermediate point by just coding
G28 the current point is considered the  intermediate point. See 10.7.8 in Using MACH3TURN manual for definition of the
g codes ( which can be confusing ).

I strongly suggest you actually spend some time playing with the command using singular axis and combination of both axes when using G28. The actual axes movement can get confusing quickly so be care full.

RICH


 

Title: Re: homing sequence (G28)
Post by: Fred_evans on February 10, 2019, 01:07:30 PM

thanks Rich,
Yes was confused -I actually wrote a small piece of code to see what would happen
with the various combinations but the closest I could get was that X moved to Xzero (crash!!)
before moving out -But I will try again

regards fred

Title: Re: homing sequence (G28)
Post by: RICH on February 10, 2019, 05:57:58 PM

Start with simple G28 moves and note what you thought it would do and what actually happens.
Note also the modes your in and if there are work offsets etc.

Now go play some........ lets us know what your score is as to what you thought would happen compared to what actualy happened.  ;)

RICH