[Hnguyen]

Hello everyone, how is everyone doing?

I’ve just started working on a new machine our company just acquired. It’s a Nakamura NTJ-100 with Fanuc 31i. And I’m having issue with tapping cycle. And I don’t have any experiences about it. The spindle is limit to 55-56 Rpm when tapping even though it’s commanded S300 or whatever I’ve tried S1600 and it still tapping at 55RPM. Any helps is appreciated.

[CadCamSam]

Is there an M-code to select a different gear?

[Hnguyen]

No M code to select different gear

G0 C0
G0 z1. Y0 X0
M29 s300
G84. R-.9 z-.375 F.025 M86(locked c-axis)
G80

It will tap and gives good thread but just slow!

[CadCamSam]

check out these parameters"
3705 B3(sgt)
3761
3762
5200 B1(vgr)
5201 B2(tdr)
5203 B3(rgs)
5241
5242
5243
5244

[Hnguyen]

Thanks CadCamSam
This is what I know
5241 s1 1000
S2 3200
5242 s1 1000
S2 1600
5243 s1 1000
S2 3200
5244 s1 1000
S2 3200

We have three of these machines and the above 5241-5244 are the same. Other two work fine, for this particular machine the tool is mounted at a different orientation for this particular part, Axial vs radial.
Will try playing with your suggested parameters tomorrow morning

In the mean time I did Hand coded to tap the long way with no good result. Thread oversized occasionally. Spindle and feed are probably not synched

[CadCamSam]

I see. I would wonder if you have a X axis encoder for rigid tapping. That may be an option, or not properly setup. Try doing the same on the other machines.

[Hnguyen]

I tried them parameters you suggested, it didn’t improve the Rpm

This morning we tried running the tapping code on the other machine (Machine F) and it worked as expected. Engineer thinks it parameters issue and wants to download parameters of the two machines and do a comparison. Thanks for all the input CadCamSam