deckel tapping

Presume I have an FP1 (FPS 300M actually with power z), and I want to do some drilling/tapping, and that I have a tapmatic or procunier. What technique do you all use for this, the quill on vertical head, or the z-axis? Not having used an FP1, I'm wondering whether the z-axis has enough finese to properly manage the tapping?

?

I can't figure out how you'd use the z axis on a *manual* milling machine to tap, even with a tapmatic...

Me, I put tighten the tap in a collet and use the quill.
No tapmatic needed in general.

TNB said:

? Me, I put tighten the tap in a collet and use the quill.

Click to expand...

I've never tried this, always afraid of breaking the tap off in the work. I assume you do this at the lowest speed (40 rpm) and only with larger taps (M8 and up?). Since you are not reversing to break chips, do you use spiral taps? Do you remove the taps by hand? Or only do this for through-holes?

Here is my take:
First off , that machine (i am guessing) has a spindle reverse and the feed is via separate drive motor (DC) ...if this is true
then you don't need a tapping head...You can just reverse the spindle and back the tap out....
Might be faster to use a tapping head, but they use up valuable head room that is in short supply on the FP1.....

If you wish to tap using the Z and power feed, then you must use a compression.extension tap holder.
The depth a tap goes is a function of the tap pitch and the exact RPM that the spindle is rotating...Depth then becomes a time function over the speed as the tap makes its own depth (time/speed)

Easiest is just use a rigid tap holder or collet in the vertical spindle and run the tap down using the quill....when it hits depth, reverse the spindle and back it out....
If tapping blind holes. there are friction overload drivers that will release at a settable torque., can run them down till they hit bottom and hopefully the drive will release...Me , i just mark the depth with a sharpie on the tap, a bit short of the depth needed. Run it in till the line is reached...
Using a tap driver with "Bliz" style collets, I just uncouple the tap and allow the quill to raise up out of the way, then finish to final using a tap handle....

Takes a bit of time , but way less than removing a broken tap....
Cheers Ross

Ross, your experience and expertise really shines, VERY helpful, thanks

I am using a similar technique to Ross's, that is tap in a drill chuck or collet, start the spindle and let the tap drag the quill down. Can go pretty low in tap size (I think I've tried M4 without issues) if the quill spring does not have too much preload.

For blind holes, stop and finish by hand (Ross's brake on the FP2 surely would help here...). For through holes you don't have to be that careful stopping. I also remove the tap with the spindle for through holes, switch to high gear and reverse with the inching wheel (that's why I like the standard diameter, large, inching wheel).

I recently made some BXA lathe toolholders so I tapped around 30 M10 holes. Spiral tap, lovely long chips gushing out, no issues at all. A 'reverse' switch would definitely help though.

BR,
Thanos

AlfaGTA said:

Easiest is just use a rigid tap holder or collet in the vertical spindle and run the tap down using the quill....when it hits depth, reverse the spindle and back it out....

Click to expand...

Ross, what style taps do you use? Straight or helix groove? What's the smallest tap size you do this way? Note that my FP2 does not have a spindle reverse so I would have to go all the way down, then open the collet and remove the tap with a handle. (Just saw Thano's comment, he's right, I could also run it out backwards by hand with the inching wheel.)

Hi all,

For just a few holes i normally put a tap in the drillchuck and rotate my spindle with the wrench on the drawbar while guiding the tap down with the big knurled disc on the left.

I have the long reach head so i can turn it of and let it spin freely.

Works great even for small taps.

Greetings,

Peter


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Bruce:
Pretty much use what is in the drawer and SHARP!!!!
I prefer the spiral flute taps in sizes at 8mm and over.
Smaller i like the two flute guys, although i will also use 4 flute hand taps if they are sharp...that's the key IMO......
As to minimum size...generally 4mm by power and in the inch world...#10.
Generally below that i use a "T" style tap handle (Starret # 93-A, or 93-B with center drilling at handle end) Do the drilling using a chuck, then fit my tap center...( i have a piece of 1/2" drill rod aboit 2 1/2" long that i have turned via collet with a 60* center at one end, then torch heat treated the tapered end to be hard) Anyway i put the stubby center in the same chuck and user that to center the tap using the center drilling at the end of the
tap handle....run the tap in by hand following the tap handle with the center using the quill. Keeps everything straight and the center helps take the side thrust you generate turning the handle.
I will use this technique if i have doubts about the sharpness of the tap or worried about the hardness of the material even on larger sizes....

In general i am a "Chicken" when tapping....often times threaded holes come into a project well down the work schedule, so often you have already invested considerable time and effort, and breaking a tap off in a chunk
of tool steel just before the final operation is a real pisser...Don't own an EDM machine so i exercise caution on tapping ....
Production (which i don't do) is different...there you gotta push it to make the quote pay...

Cheers Ross

Spring loaded tap centers help a bit in hand tapping, saves you having to push down with the quill. The guide has to be nice quality though, so a shop made one is, probably, wisest choice than a generic cheapy

Br,
Thanos