Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: gifre70 on March 03, 2008, 03:32:15 PM

Title: G95 lathe problem
Post by: gifre70 on March 03, 2008, 03:32:15 PM
hi.
i have problems in my lathe. when i set it in g95 the CSS led never light and the lathe never compensate the feed rate when i up the rpm.
when threading the same ocur i have a litle over rpm  for example when i set to 100rpm i get 127rpm and no compesation is done in the feed rate consecuentliy the thread pitch is minor.
when adjust the rpm via the vfd and i get 100rpm then the pitch is ok whit a litle deviation.
the spindle index pulse is clear and i compared the TRUE DRO whit a profesional tacometer and i found a 2-3 rpm deviation in all range 30 to 2000 of my lathe.
any idea what happend ???
tks. Josep
Title: Re: G95 lathe problem
Post by: Graham Waterworth on March 03, 2008, 04:36:04 PM
If you are running at low RPM's then it is better to use a multi slot (4 slots works well) index wheel and timing input instead of a single slot and index.

Graham.
Title: Re: G95 lathe problem
Post by: gifre70 on March 04, 2008, 11:06:49 AM
tks. for your help Graham.
i tried to put a slotted disk (4 slots) as you said. OK  now the threading have more precision.
anyway the CSS led is not light when i am in G95 mode and when i facing no correction is added to X axe.
in the CSS Dro yes i can see the correction versus X axis position but the X servo stay in the same speed.

Josep
Title: Re: G95 lathe problem
Post by: vmax549 on March 04, 2008, 11:37:47 AM
Also keep in mind that if using multiple slots ONE most be larger than the others so mach can use it for the timeing signal.
Title: Re: G95 lathe problem
Post by: Overloaded on March 04, 2008, 11:56:16 AM
Good point vmax,
1 slot must be at LEAST 50% wider than the others.
RC
Title: Re: G95 lathe problem
Post by: vmax549 on March 04, 2008, 12:16:04 PM
If you go to the diagnopstic page in mach and slowly turn the spindle by hand do you see one of the port leds light on and off as you rotate the spindle??

If not then Mach is not seeing the signal. Also you must set up the signal in the MACH setup so mach knows what it is.

ALso make sure on the debounce setting for the spindle it is set to zero.

(;-) TP
Title: Re: G95 lathe problem
Post by: Graham Waterworth on March 04, 2008, 12:30:48 PM
Have a look at this post too :-

http://www.machsupport.com/forum/index.php/topic,5494.0.html

Graham.
Title: Re: G95 lathe problem
Post by: gifre70 on March 04, 2008, 02:12:50 PM
hi.
tks. to all lathemans in the forum !!!
OK. Graham the key is in the post indicated  :) i printed this post and put it near the lathe.
now i understand the CSS i was confused betwen G95-G96 gcode G96 firing the CSS led.

Josep