Correct tapping cycle???

I have to tap some 1/2"-13 threads about 3/4" deep
using a SuperMax Max1 VMC with a Mitsubishi MELDAS
M3 controller. (Very similar to FUNAC).

Parameter is set to threads per inch, not pitch.

Is this code correct???

G84 Z-.75 E13 R.1

E=threads per inch.

Do you have to set RPM first?

Do you need to set a G28 or something else.

Having a lot of problems. Just want to be sure code is OK.

Just wanted to get this job done right before China steals
it from the USA & I am out of work. HANG ON FOLKS.

I should talk. My machine is an import.

Yes, you have to have rpms then the correct feed rate.

M03S260
G84R.--Z---F20.0

I am not sure about the misubishi control, but the prefered and fastest method of execution for fanuc compatable machines is as follows for the spindle

S250M05
G84X...Y....Z...R...E(F)...
Spinde has to orientate in a G84 cyle and having to stop the spindle prior to this will only slow your cycle down.

As far as the import machine ..... if you were to poll every shop and machine tool owner in the USA , you would find that an overwhelming majority own import machines, with imported controllers, yet some may have been assembled here in the states. I prefer Japanese Machines, and most definately Fanuc controllers for the type of work I do.

We have Okuma & Howa and Toyoda HMC's, both with Fanuc 16i controls. The tapping formats vary some, but both require that the spindle speed be in the G84 line:

O & H
G84M29X0.Y0.R.25Z-1.F.0769S250

TOYODA
G84.2X0.Y0.R.25Z-1.F.0769S250

or you could do what i do when in doubt....use a Lyndex spring loaded tapping head and just do

G00X___Y___
Z0.1
S260M03
G01Z-0.75F0.0768
M04
Z0.1F0.0770

note the feed rate variations. this is to allow for the spring action to work properly and not overcut the threads. if you were hard driving the tap you would have to program the feed exactly.

The Meldas M3 wants the speed set in the block before the G84 command.

M3 S260
G98 or G99 G84 Xx1 Yy1 Zz1 Rr1 Ff1 Pp1, Rr2

This is similar to Fanuc with the addition of Pp1 for dwell and the ,Rr2 (must be preceeded by a coma) which is the controls way of choosing between syncronous and asyncronous tapping.

,R0 = Asyncronous (use a sprung holder)

,R1 = Syncronous (Rigid tap)

Pp1 is for a dwell if you want one. (It can be left out)

Ff1 is the feed Formula is F=1/TPI*S or F= S/TPI

IE 260/13 = F20.0

RODMAN