Re: [CAD_CAM_EDM_DRO] cnc tapping options for making cnc tooling table

skykotech wrote:

>I want to make a tooling table for my cnc mill, and possibly another
>table for a medium gantry mill I am building. I haven't exactly
>decided how large the table will be or what size holes it will have,
>but something along the lines of 16" x 32" x 1" with 420 tapped holes
>would probably be the largest. Now, I am not going to hand tap 420
>holes, so I need an option for a cnc tapper.
>
>Option 1: Procunier tapping head - fast but expensive ($500+ new)
>
>

I got a Procunier 15000 series "CNC" tapping head on eBay for a little over
$100. It drives the tap 1:1 when pushing forward and 2:1 reverse when
pulling
up on the tap. It is for 0-1/4" taps. It has no overload clutch, it
depends on the
CNC spindle to know when to stop advancing. It is the fastest thing for
tapping
I've ever seen. I did a 12 x 12 pattern of 10-32 holes in about 15 minutes.

I just got some "thrillers", taps with a drilling tip on them, and so I
now drill and
tap in one operation, even faster! You have to enter the spindle RPM
into a calculation
to figure the feedrates.

I use helical flute taps for blind holes, and once you get the depth set
right, it
will tap hundreds of holes with no problems at all.

>Option 2: Threadmilling - slow, but possibly much cheaper
>
>

I wouldn't do this for anything less than about 3/8". I have a "single row"
threadmill that you have to orbit the entire thread, one turn at a time.
But, it will do all thread pitches over a fairly wide range with the one
tool.
I have used it twice in about 5 years.

>I am using EMC and can do full three axis moves, but I don't have
>computer control over the spindle speed, position or direction. All
>of this is making me lean toward threadmilling, perhaps 1/4" 20TPI
>holes using a single point right hand tool like the Micro 100 1801000
>which has a min. hole dia. of .180", a projection of 0.040", a shank
>of 0.25" and a depth of 1.0". I have no clue if this would be the
>right tool for threadmilling holes in an aluminum cnc tooling table,
>but it is pretty cheap, solid carbide for $22.
>
>

It will work, but it is REAL slow. I have a program for cranking out
the G-code
for it. The tapping head is probably 100 times faster. I have a program to
generate the G-code for that, too.

Jon