[mwbridgwater]

Although I've been in the business for over 30 years, I've managed to never tap with a CNC mill before. New place I'm working at has a Fadal VMC4020 and I need to be able to do this with it. I don't know if the machine has rigid tapping or not... they've got a floating tap holder, so I figure I'll just pick a low RPM, calculate a feed rate that's just slightly slower than the pitch of the thread, and the floating holder extends just a bit by the time I get through the hole (10-32 through holes in 1/8" aluminum)... Right? Then an M05, followed by an M04, or what?

[rodney247]

Well easy test go into MDI and type G84.2 enter start , and if the spindle spins 2 or 3 times and then holds it firmly in place ....... you have rigid tapping.

If the machine is in Format1 the code to do a 10-32 floating tap example

M6T1 (10-32 FLOATING TAP
G90G0G17G80
H1Z.2M7
G84G99X1.Y1.Z-.75R0+.2F750.Q.0313
X....Y.....
X.....Y.....
G80
M5M9
M6T2

[banjodave]

I've tapped thousands of holes on Fadal 3016, 4020 and 6030's. All of ours had rigid tapping option. Even without it you shouldn't need to add extra M05/M04 commands etc. It will still do the same thing with the G84 command minus the precise spindle encoder timing lockup. Basic code as follows should work with a 10-32 tap:

T3 M06
G00 G80 G90 S960 M03
G58 X12. Y-2.
G43 H03 Z0.5 M08
G84 G98 Z-0.92 F30. R0.1
X14. Y-2.719
X15. Y-4.453 M09
G00 Z1.
M01

I always just add a zero to my thread pitch and program my feed in intervals of 10 IPM. Example 1/2-20 tap runs 400 rpm @ F20 or 600 at F30 etc.

[rodney247]

LOL...... this is definitely Halloween because that is a Trick example of a tapping cycle Banjo..... good one

Thats a snap your tap everytime program...... but that wont happen because the fadal will just give you an error and not run anyways

[rodney247]

mwbridgwater you can download all the Fadal manuals here for free here is the part that gives you all the examples of Fixed Cycles https://itscnc.com/images/Sect_4_Fixed_Cycles.pdf

[mwbridgwater]

Thanks, rodney!