Machinist

[Lawrence London <lfljvenaura@gmail.com>]

Drilling & tapping with vertical mill
http://www.practicalmachinist.com/vb/general/drilling-tapping-vertical-mill-335463/

You can just chuck a tap into a collet holder and feed it in, reverse the motor, and follow it out with the quill. Not the most elegant way, and if you push/pull too hard as the tap exits you can tweak the start of the thread, but it works.

Really need to be paying attention though as a bit of inattention at the bottom of the feed and you might make a little kaboom.

through hole yes.. dead end holes and then you need to count you turns..

run the mill in back gear @ 100rpm or so, set the quill stop to slightly lower than final depth . DON'T TAKE YOUR HAND
OFF OF THE REVERSING SWITCH !!!!!!! if these are through holes, just put the part on parallels and don't bother with
the quill stop . just watch the tap and quick-reverse when you see it disappear , otherwise watch the quill stop.

i just use a drill chuck for anything 3/8 or smaller. let the machine do the feeding in and out, the quill will follow the thread , give it a nudge as it
exits. it becomes second nature.

On a manual mill I'd drill all the holes first then power tap at about 200-300 RPM as noted above.
Thorough are easy. Blind we sharpie color the tap at the depth to tell us when to hit reverse. This gets you within 2 turns.
Sometimes we will wrap the tap with electrical or duct tape at depth but if you hit the tape you have to retape.
On say 5-10 holes maybe you drill and then change to the tap before moving.
Drill chucks work best on blind holes as if you blow the depth the tap will spin in the chuck if you do not overtighten it.
The will also spin when the get dull without breaking if done right.
There is a bit of a learned art on how tight to turn the chuck key for different tap sizes and types.
Less is better as you learn. Better to stall shallow in the hole than to break in the hole.
Bad thing being you don't learn the high limit you can push until you break some.
The quill must be very free to retract and/or gets some help on the way out or you make "loose" threads.

Power tapping is scary at first and many use too low of a speed for the cutting tool to work efficiently and have a long life.

Or you could use a Wahlstrom chuck and speed things up a bit.
Wahlstrom chuck: drilling, chamfering and tapping 5/16-18 - YouTube

Thats a pretty neat chuck. I don't tap with a keyless though....looks like its not an issue with that chuck

The OP hasn't said what the parts look like, but where ever possible, do the ops sequentially - drill everything, counterbore, tap etc using a vice stop for positioning so you're not swapping tooling. Not having a Wahlstrom, its a lot faster imo to swap parts out the vise

For 200 holes, I would look at it as a great excuse to buy a Tapmatic or a Wahlstrom!

And if they are through holes, use a spiral-point tap.

I agree. You can probably pick up a used one. I have used them and they are great: feed down until you reach full depth then feed up. You don't have to reverse the motor. And they usually back out faster than when they are going in so the job goes fast.

I would use the tap-matic

but don't they make "Dr-aps";-) Drill and tap combined? Very useful for pedestrian applications.
1/4"-2 Coarse Thread Combination Tap & Drill Bit | Fastenal

likely the job done...but did anyone mention drill and tap tool
1/4-2 UNC, H3, 2-1/2 Inch Overall Length, 827727 - MSC

yes only for through holes.

Drill Press - Gear Driven - DP-15G | Baileigh Industrial

Advert states "Mt-4" and I can't find a service book, for an exploded view.

I suspect poster removed chuck and is looking at the adapter, but please post some pictures,
and wind the quill all the way down looking for a drift key slot.

It's an MT4, kind of surprised me when I saw it, BTW it's a brand new press. I guess I could go over to the Baileigh thread and post this tho.. But I know u guys are sharper than that.. lol...

I'll post some picts when I get over to the shop after lunch. I just uncreated it.. No manual came with it so I'll have to run one down.. Not a bad looking press, sez it's set up for tapping but I'd like a clutch tapping head anyway like the TapMatic..

Baileigh 20-inches gear head drill press is rigidly designed for heavy drilling. The column is a massive 5-1/2-inches diameter to help reduce possible flexing during heavy feeds at maximum capacity, which is 1-1/2-inches through mild steel. The base and table are made from a heavy casting and both have large T-slots to ensure a proper hold of the material being drilled. It has a heavy industrial grade gear system that allows for an array of speeds to work with many different materials for drilling and tapping. To properly transfer the power from the gear head drill press to the material we have as standard a # 4 morse taper. The drill press comes standard with a coolant system, guarding, a chuck and a halogen light. This Baileigh Industrial drill press offers a lot of power at a very economical value to the machine shop or fabrication shop owner. Specification: 3.5 hp motor, 108 - 1800 rpm spindle speed, MT 4 spindle taper, 1.3-inches tapping capacity, table size 20-inches length by 16-inches width, 220 volt 3-phase power, 1.5-inches drill capacity, 7.48-inches spindle travel, Base measures 19-1/2-inches length by 28-inches width.