Backlash wrote:

All the tap heads I have rebuilt by Procunier and Ettco use a cork lined
double cone clutch and a set of planetary gears inside. The tap is driven
into the work by one side of the cone clutch until the body of the tapper is
stopped by a physical limiter on the drill press or other machine. The tap
loses driving friction at this point by the cone clutch disengaging, and
goes into a "neutral", which limits tapping depth. You can pause tapping at
this point if you desire, by keeping the head floating in this neutral zone,
with your feed handle. Whenever downward pressure is released, the other
face of the cone clutch, along with the planetary gears come into play,
reversing the taps rotation to back out of the hole. The gearing speeds up
this process of getting out of the hole more quickly. Once the tap clears
the work, it automatically switches directions via a coil spring against the
cone clutch to once again drive in a right hand direction. The screws you
see around the lower end of the tapping head are the spindles of the
planetary gears. Take the top off. It won't explode. Parts are not cheap. I
just spent over $400 converting a Procunier from Morse taper mounting over
for use on a Burgmaster 2BH with a threaded spindle.

RJ

--
"Have no one say it, and say it to your shame, that all was well here, until
YOU came."

"Aribert" wrote in message
om...
Last week I went to a local machinery auction and for once there were
more lots than interested bidders. I bid and won a bench grinder for
$5, the auctioneer included the two prior lots that did not sell for
$5. One of those two lots consisted of an antique tapping head. The
brand name is ETTCO, Eastern Tube & Tool Co. w/ a patent lable of Aug
1924. I have never used a tapping head before - I have occasionaly
tapped using my Bridgeport w/ a tap in a collet. In playing with the
tapping head by hand, I have been able to make it reverse direction
but I am unsure of exactly what makes it change direction - is it
torque based or is it when the unit receives an axial load (tap
botomed out)? Do tapping heads typically have any adjustments? THere
are a couple of set screws that might be intended for ajustment but
there are no markings on the body nor any indication that there has
been frequent adjustments made to these set screws.


And store them in an upright position to keep oil from getting on the clutch.

michael