Machsupport Forum

Mach Discussion => Mach4 General Discussion => Topic started by: rhtuttle on January 30, 2018, 04:23:24 PM

Title: G91 - Lathe
Post by: rhtuttle on January 30, 2018, 04:23:24 PM

Since lathe doesn't have a g91 you swap letters for relative moves
x ->u
y->v
z->w
a->?
b->?
c->h?

Anyone know the abc for sure?

TIA

RT

Title: Re: G91 - Lathe
Post by: rhtuttle on February 05, 2018, 05:32:10 PM

Lathe does not support incremental/relative moves for the A or B axis. 

Title: Re: G91 - Lathe
Post by: pirat21 on March 02, 2018, 01:51:54 PM

How can you thread threads in mach 3? I mean the control of the spindle through the encoder, or rather the asynchronous motor - chastotnik - encoder - Mach 3 or maybe I do not understand something?

Title: Re: G91 - Lathe
Post by: Steve Stallings on March 05, 2018, 08:01:38 AM

You have asked our question in the Mach4 section of the forum, but the answer
for Mach3 is the same as for Mach4. The thread tracking is accomplished by
controlling the Z axis travel rate, not by altering the spindle speed. Feedback
from the spindle speed sensor is used by Mach to calculate the needed travel
rate to make the threads and adapts within reason if the spindle speed changes
while cutting.

The typical Mach3 setup cannot use a true encoder, and instead uses a single
pulse per revolution to measure the spindle speed. Many encoders have an
"index" pulse which can be used for this purpose.