Auto reverse tapping head tips?

[Greg White]

I have the same heads as the OP,all mine double thier speed on the way out,yes double,I goto location,call sub,next location,call sub,simple 2 line sub,fed in,feed out twices as fast.
The reason for tapping heads here is to save the wear tear of reversing spindle 9 million times a day.

 

[rklopp]

By 100% I'm pretty sure he means at 100% of the theoretical advance rate given the thread pitch* and RPM. That is, feed rate = 100% * RPM * pitch. If you are using a tension-compression tap chuck, you would typically feed at 90-95% of the theoretical value so that the tap pulls ahead of the feed. That guarantees the thrust is coming from the relatively wimpy chuck spring instead of the hard spindle bearings, and keeps you from buggering the threads or breaking the tap if the machine's feed and spindle rotation are not closely synchronized - like on my old Deckel FP2NC.

I don't thinks it'd be a great idea to under-feed a "normal" Procunier or Tapmatic head all day long, because you'd be constantly slipping the clutch and wear it out.

*Assuming single-start thread so that pitch = lead in case anyone is picking nits.

 

[DavidScott]

Ok, I am stuck thinking of using a Tapmatic type tapper on a cnc as that is all I ever used. The only Procunier I used was the "drill press" type on a knee mill. The Tapmatics reversed differently than the Procunier so that is why the info I am giving isn't quite right. When your head stops moving down while tapping your tap will stop moving down, that is not the case with a Tapmatic. It will keep tapping for another .15"ish. With a Tapmatic you must feed the tap at pretty close the same rate as it wants to go based on the spindle speed or else you will have nasty problems. With a Procunier you can feed slower without any issues, other than clutch wear as rklopp pointed out. If your tapping head spindle doesn't have a "cushion" in the spindle for feeding too fast then you will want to feed around 95-98% of the feed rate based on the pitch and spindle speed.

What speed you want to drive your tap depends on your tap. Cut vs form, what percentage of thread you are creating, and if/what coating it has will make a big difference. I am sorry if this is too detailed but I do larger part runs where saving or losing a second a hole matters. Your spindle speed for tapping will be between 1000rpm to as fast as your tapper will go.

Keep in mind that we are all giving general advice and when you start defining the details that advice will change. We learned most of this by trial and error. You are going to have to take all of our advice and keep it in mind when setting up and running your tapper.

I really liked these reversing tapping heads. When the company I worked for got a Fadal and we were tapping up to 80,000 holes a month with it that is when I fell in love with them. Tapping those holes using ridged tapping would have taken about 30 times longer and probably kill a few spindle drives, according to the tech who installed it. Watching that Fadal tap 4-40 holes about as fast as it could spot them at 3000 rpm through 1/8" aluminum plate was impressive.

Here is the manual for your tapper. Whatever you do DON'T OIL IT TOO MUCH!

 

[Ox]

As well, I have zero experience with Procunier.
So much of my info is for naught.


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Think Snow Eh!
Ox

 

[M. Moore]

Rklopp, not sure if your feed rate formula is correct? The rpm for a 4mm tap is 970, the pitch is 0.7. For inches per minute you need rpm x pitch x 0.03937 which in this case gives a feed rate of 26 ipm, so I can go 50 ipm to retract. I will start slower for testing and speed up if all is well.

DavidS, thanks for the additional info and the link to the manual page! I will have to take both apart to clean and grease them as I have never done either head yet.

Ox, all your info was good, my query was lacking info originally.