At some
point we’re going to get into ‘what to look for when buying a DP’. I’m sure
that will help anyone who is contemplating adding a new machine to their shop.
For now,
let’s get back to our rundown.
Where’d
we leave off? Oh yes, we were at the chuck and the next nearest thing to talk
about is the spindle. The ‘spindle’ is usually driven by a stepped-cone pulley
or pulleys that are connected by a v-belt to a similar pulley on a motor. The
‘motor’ is bolted to a plate that is located at the rear of the head casting at
the rear of the column. The average range of speeds of the typical DP is 250rpm
to about 3000rpm. Delta used to manufacturer a ‘super hi-speed’ Drill Press. It
was so named because the bit speed was around 10,000rpm. The motor only turned
at 3450rpm, but because of the belt ratio, it could really turn ‘n burn. It
seems that jewelers loved it. Since the motor shaft stands vertically, a sealed
ball bearing motor is best suited for a Drill Press. For average work, a
one-quarter or three-quarter horsepower motor usually meets most requirements.
The
capacity, or ‘size’ of a Drill Press is determined by the distance from the
center of the drill bit to the front of the column - then doubled. For
instance, a 12-inch Drill Press can drill to the center of a 12-inch diameter
circle, but the distance from the center of the bit to the front of the column
is only 6 inches. This is how all Drill Presses are measured. One of the most
versatile Drill Presses was the “Ram Radial” Drill Press. This was an
industrial Drill Press that was used a lot, during the Second World War, in
airplane factories. The head had a long appendage fastened to its back and that
casting rolled inside a ball bearing track. What this allowed was that the head
could be moved backwards and forwards almost 3 feet. I’m working off memory but
as I recall this press could drill to the center of a 72-inch circle, or down
to about an 8-inch circle…and any and all points in between. It was such a
popular concept, but one that most home shop guys could not afford, that back
in the 1970’s, Rockwell International created a home shop version that could
drill to the center of a 32-inch circle. It could also slide in and out, just
like its bigger brother, which enabled it to be just as versatile.
Next
week we’ll outline a few tips to keep in mind when you’re out shopping for your
new Drill Press.
Send your questions or comments to:
Toolsmartz@bellsouth.net and we’ll see what
we can do to help you
No comments:
Post a Comment