tapping

[mbmmachining]

this is my first post here ever.
i' have a 4020 without rigid tapping and i have been having trouble with it.
i 've worked with fadal for many year.all of them with rigid tapping.
i always used this line
g98 g84.1 x? y? r.1 q 1/picth z? f beeing same as rpm
with this machine is diferent.
i'm using a tension compression holder.
this is what happens.
spindle goes in but stops before reaches full depth while z axis keeps going down.
i have to mention that we change the 15hp spindle drive for a 20 hp spindle drive. i don't know if it matters.
thanks for any help in this matter!!

[mquach]

use g84 only because you don't have rigid tapping

[mbmmachining]

i did.
i mean,the machine performes the cycle but doesn't go to the full depth.
instead the spindle stops but z keep going down to the depth in the program.

[manoharan]

hi , Try this below:
G84.1 X?Y?R.1Z?F[1/pitch]
OR
G84X?Y?R.5Z?F[1/pitch]

[mquach]

if you have a rigid tapping then you don't need to use a tension holder.
Use collet instead & your lines should look like this.

T6M6(M8 X 1.25 STRAIGHT TAP)
s160M5G80M90
G84.2
E1G90G0X1.5155Y-.875
G43Z2.H6M8
G84.1G98Z-.6R.1S160F7.874
X0.Y1.75
X-1.5155Y-.875
G80Z2.M9
G91G28Z0.M5
G90X0.Y8.E48

Try this.

[ltmquik]

I think that he said that he did not have ridgid tap!

Use a Bore-Bore command with out a dwell at the end.

[banshee1a]

First thing, when you swapped the spindle drive motor, did you re-calibrate it. Not sure it thats the right term, but several years ago we had to replace a spindle on one of our Fadals, and they had to calibrate it (I think its called spindle gain not sure on that either). If not the spindle may be turning slower or faster than the controller says it is and it won't tap very well. Another thing is that if you watch the compression holder when the tap starts into the part you will see the holder compress until it finally reaches the point where it can drive the tap. This compression is why your holes are comming out short. You need to program the spindle to go deeper. At least this is how the tension/compression holders we have work. We don't use them on our Fadals as they all have rigid tap, but the guys in the tool crib weren't paying attention and sent it down. Even without rigid tap you can still use a standard rigid tap holder. We did this for the longest time before we started using rigid tap, because the operators kept taking out the .1 on the G84, because they weren't told we had rigid tapping with no problems. But if your spindle is not right you will have problems. This is the code we would use for a 3/8-16 tap,
going 1" deep using format 2 which is similar to a fanuc:
G84G98X?Y?Z-1.R.2S160F10.
We always put the rpm in the tap cycle, not sure if you need it on a G84, but we put it there anyway.

[mbmmachining]

thanks all!
i'll try your suggestions.
i'll let you guys know!

[machinist_1]

Sounds like you need to run M84 in MDI. Thats the spindle cali. Just cycle start it and let it go (15-20minutes)

[machinist_1]

Oh, if your using a FANUC control set your R value to 3 times the pitch. The spindle needs a couple revs sync. with the Z feed.

[billystein]

if you have an older fadal remember to keep the rpm under 400. I don't know when the rpms went up but I still use 400 max on fadals.

[machinist_1]

The machine that I am running (2007), will tap 1/4-20 at 5000 rpm with no problem. It will most likely go the full rpm's (10000) but I don't see the need.