Tapping with Super X3

[doubletop]

Before I mangle a few taps working out what to do has anybody got any tips, tricks do's or don'ts when using the Sieg SX3 tapping function? There's nothing in the manual and I can't find much on a web search other than here:

http://www.mini-lathe.com/X3_mill/Sx3rvw/SX3-4.htm

Where the author says:

My conclusion is that the power tapping feature could prove to be a useful time saver if I had to tap a bunch of holes to the same size. I can't really imagine using it, though, with a tap smaller than 1/4" diameter. My advice to new Super X3 owners would be to do a lot of practice with this feature before you attempt to use it on a workpiece that you can't afford to mess up.

I'd imagine the situation where I'd need to tap a series of holes over 1/4" would be very infrequent. I'd also imagine messing up would be a lot more frequent.


Pete

 

[Majorstrain]

Hi Pete,
I regularly power tap 3mm (~1/8") and up on my old Bridgeport. The smallest I've used is a 2mm tap in aluminium.
I highly recommend spiral fluted taps as they dray the swarf out of the hole like a drill rather than pushing it forward like a normal tap. I picked up a set of Sutton spiral fluted taps and matching drills. Not all that cheep but well worth it in the long run.

That being said I also tap with the standard taps as well but mainly through hole.

The fewof tips I have to save breaking them is firstly to just nip up the collet or chuck, if the tap want's to stop it will just spin in the holder (does the same if you bottom out as well). You can stop the mill in position and nip it up a bit more if it spun for no good reason then reverse it up a couple of threads by hand and go again.
The second tip is to keep up the tapping fluid while tapping. They lockup a lot less when I do this.
For steel I usually drill the tapping hole a touch bigger than recommended.

The last tip is let the tap draw itself in and out once it starts threading. I usually counter the feed handle weight on reversing a small tap in ally. you might have to counter the spindle spring tension on feeding in if it is strong.

I've also had good success power tapping with a battery drill. Same tips as above and don't let the drill tilt off axis. I have the view that most taps break because the are bent off axis when hand tapping, not because they fail torsionally on axis.

This is just how I do it. I'm comfortable tapping above 100rpm now which is what your X3 will tap at. (Mainly because of the tap being able to spin if it bottoms)
I've only broken 1 M3 tap and that was on the way out of the hole when it jammed with swarf in the early days when I used to hold the taps real tight in the collet.

This is M5 @ 50rpm in 4140 steel
http://www.youtube.com/v/mMU3Q0ovJ2...xcfcfcf&hl=en_US&feature=player_embedded&fs=1

This is M10 @ 50rpm in 4140 steel
http://www.youtube.com/v/VSVIPNA0oD...xcfcfcf&hl=en_US&feature=player_embedded&fs=1
Hope this helps
Cheers,
Phil

 

[SBWHART]

I use my X3 to tap but the smallest I've gone down to is M4,

Phil's given some good advice particularly about not having the chuck too tight.

Stew

 

[doubletop]

Phil/Stew

That is really helpful thanks and clearly those fluted taps work as advertised. The tip of the loosely holding the tap in the chuck is just the sort of thing I was looking for. It would have taken a few sacrifices to the god of "give it a go" before I'd worked that out.

Some thoughts did cross my mind that with all these smart electronics controlling the motor these days some sort of torque control could be set up for tapping, say, based on monitoring motor current and a means of selecting tap size that managed speed and jogged or auto reversed under certain conditions. All the major bits are already in the box on the new X3 with the DC motor. It would need a sensor, control box with tap size selector, the ubiquitous PIC micro with the logic applying a torque/speed/tap table and you have hands free tapping, even for blind holes. I may have to revert to my primary skillset and think about it. (Anybody know where the new X3 schematics could be found?)

Alternatively the mechanical approach with some sort of secondary chuck with a slipping interface to the primary chuck would save the tap from being gouged. But surely somebody has done that already?

Anyway less of the rambling I'll psych myself up to sacrifice some taps.

Pete