tapping head questions

So as some may remember I Have a Van Norman 22l mill that I am reasonably happy with. It does not however have a "quill". I have a job that requires tapping 200+ 5/8nc in 1" 6061.

What kind of tapping head would work for this?

Auto Reverse would be nice but not critical.
Self feeding? is what i am looking for. without a quill I need something that is going to allow the tap to feed.

I have looked at a lot of tapping heads but the descriptions leave me in doubt as to what the actually do.

my alternative is to build a tapping jig and run the taps in with a 1/2 impact. very crude but my tests indicate it will work.

Any help would be appreciated.

Have you got a drill press, if so what size and speed range?

I do. It is a "nice" general purpose drill press. 215rpm min. speed, 5/8 chuck, not nearly enough torque.

for that many holes, beg, borrow a mag drill, mag it down to a plate, use it like any
other drill press.

Wear earplugs (for the whine of the brush motor) and have at it.

seiner said:

I do. It is a "nice" general purpose drill press. 215rpm min. speed, 5/8 chuck, not nearly enough torque.

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Not being picky - trying to help, (humour me ) what size motor has your DP got?

215 rpm is plenty slow enough,

Through hole? - use a spiral flute tap - pref for Alu

Blind hole? use spiral flute ta - again pref for Alu

IME Spiral point seem to take less torque than sp' flute, both take a lot less than normal straight flutes.

Have you tried driving the tap with your DP? ....... you may be quite surprised.

If it'll do the job, get an auto reverse tapper and you'll fly through the job.

I tried using my delta drill press on a test piece and either stopped the chuck or spun in the chuck each time I tried.
I am going to get new belts for it tomorrow and see how that works. I also ordered a couple of spiral point taps to see how they work. the tap I'm using looks great but is really quite old for a cutting tool that I can't(haven't,) sharpened

I am looking for a recommendation on what kind(brand), model, of tapping head I should be looking at for use in my mill.

My mill does have a feed of .023 so I am going to try that in test piece tomorrow although I expect failure due to the tap wanting .022 feed.

I am happy with my procunier 3 tapping head. I think the capacity is 1/2 but I will check. they are very nice heads and can be had second hand at good prices. if it cost you $400, would it be worth it? could buy a bigger dp and have the capacity to get job done and have more future versatility.

procunier 3e has 3/4" tapping capacity in aluminum when cutting threads. 9/16 when forming threads. hope this helps.

Procunier would do it

seiner said:

I do. It is a "nice" general purpose drill press. 215rpm min. speed, 5/8 chuck, not nearly enough torque.

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The largest Procunier brand tapping head will pull a GOOD 5/8 -11 tap in steel.This wont work unless you have a quill.It MIGHT work in your drillpress. Procuniers have a built in GEAR REDUCTION that reduces speed but INCREASES TORQUE and a very well designed cone clutch that gives good FEEL.You would need the largest model and it might be too tall for your drillpress also it might not fit up into your spindle. Very few drillpreses will pull a 5/8 11 tap in steel without a gear reduction tapping head Good luck Edwin

So I ordered two 5/8 three flute spiral tip taps and replaced the belts on my drill press….Butter, these taps go like a hot knife through butter. still no reverse but the job is done.

Well there ya go ....jobs a goodun

seiner said:

....My mill does have a feed of .023 so I am going to try that in test piece tomorrow although I expect failure due to the tap wanting .022 feed.

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First, it's great that you solved most of your problem (backing the tap out under power sure would be nice, though). I didn't quite get the reference to feeds of .023 and .022, however. Neither of those have an integer relationship to the pitch of the 5/8 NC thread standard. Can you please educate me ?

You need an extension compression tap holder.

Taping head is rather worthless with out a quill.

randyc said:

First, it's great that you solved most of your problem (backing the tap out under power sure would be nice, though). I didn't quite get the reference to feeds of .023 and .022, however. Neither of those have an integer relationship to the pitch of the 5/8 NC thread standard. Can you please educate me ?

Click to expand...

I just cross referenced 11 threads/inch on my lathe to come up with .022 feed/rev. i didn't actually look it up in Machineries.

seiner said:

I just cross referenced 11 threads/inch on my lathe to come up with .022 feed/rev. i didn't actually look it up in Machineries.

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So maybe I should have looked it Up. .090 is much closer to the mark.

Maybe I overlooked it, (edit: I did. Heavey Metal said it a couple comments above.) but I didn't see anyone say "tension/compression tap holder". This is not what you would consider a full-blown tap head, since there's no clutch or auto-reversal, but it's better suited to mills without a quill. Basically, the holder is restrained in rotation, but can compress or extend axially. Some holders are extension-only, others are compression-only. More desirably, you'd use a holder with a small compression range (so you can smack the tap into the work) and a longer extension range.

Find a combination of spindle RPM and elevation power feed that is close to the desired thread pitch. Mill feeds are usually marked in IPM, but you need to figure IPR for this application. If you've got an extension holder, the elevation feed should err on the low side of the thread pitch. When the tap self-feeds at the exact thread pitch, and the elevation feed is less than that, the tap will extend the holder outward. When you've tapped to depth, cut the elevation feed and reverse the spindle. Obviously, the extension range of the tap holder and the feed-to-pitch error will put a limit on the depth you can tap.

I much prefer using a Procunier head on a drill press when I can, compared to an extension tap holder on the mill, but for 5/8" taps you not have that option!