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A CUSTOMER calls and says that he wants to buy a threehole punch, but I tell
him that he really does not. To avoid the risk of falling into an
Abbott-and-Costello routine, I explain to him that a drill uses rotating drill
bits to drill through paper and a punch uses reciprocating male and female dies
to push through paper. A solid punch pin pushes paper through a female hole and
the waste exits below. A drill cuts the paper while spinning and the waste is
ejected up through its hollow shaft and exits through the top.
What's the difference? Speed, accuracy, versatility and cost.
Let's start with speed. The most common misconception in this end of our
industry is that an automatic punch is faster than a drill. It most certainly
is not. In fact, the slowest three-hole drill is faster than the fastest
automatic punch. The slowest three-hole drill can drill through a 2½ lift every
stroke.
How many strokes can you do in a minute? The fastest punch can only punch 7½ of
stock per minute. If you can drill four lifts of stock per minute you are
already ahead of the game. A good operator can drill six or seven lifts per
minute. Since many drills can drill through 2½ or 3½ lifts, it becomes even
more apparent that drilling is faster.

Talking Stock
The only stock that is clearly better to punch than drill is plastic and vinyl.
While both can be drilled (with quick strokes and slow spindle speeds),
ideally, they should be punched. Heat and friction tends to melt these stocks
and causes a mess within the drill bit. If the plastic hardens within the drill
bit, you might as well throw it away. Some operators prefer to punch heavily
varnished stock, rather than to drill it.
This is a toss up. It also depends on how sharp your bits or dies are. Drill
bits should be sharpened every three to four hours of use. Punching dies need
only be sharpened two or three times per year.
Many customers ask:
"How many sheets of paper can it punch at a time?" This is not a very good
question. If you always punch the maximum amount of paper that the punch will
allow , the more likely it is that the center sheets will have ragged holes and
you will be replacing your dies often. Dies are not cheap. A die in a
heavy-duty automatic punch should last more than 10 years. A better question to
ask:
"How many strokes a minute can it punch?" A fast punch can punch over 100
strokes per minute. If you average 10 to 15 sheets per stroke (this will not
beat up your die), that's 75,000 sheets per hour. Of course, a good operator
will be able to even better these numbers.
If accuracy, however, is your aim, then punching ought to be your game. The
only reason to punch three, five or seven round hole patterns is if the job has
to be dead-on accurate. Drilling always has that human error factor built in.
Was the lift jogged perfectly up against the side guide? The back gauge? Was it
jogged at all? Good automatic punches have four-sided registration and take the
worry away as long as the machine is setup properly.
Manual punches are either tabletop or floor-model designs. Floor-model punches
are generally used by those who have automatic punches, but cannot punch a
particular job automatically. It is either too big, too small, too thick, too
thin, a strange shape or too small a run to set up on an automatic punch. Table
top punches are mostly used by those who have small runs.
There are in-line punching machines for punching in-line with saddle binders,
folders or bookletmakers. These are not to be confused with the attachments
that fit into three-knife trimmers, which can take a long time to set up and
can only punch very thin booklets. In-line punches can roll up to any
compatible machine, set up quickly and be fed with an on-demand basis. Some of
these machines can punch booklets up to 1" to 4" thick.
Variety of Options
Automatic punching machines vary greatly in cost and versatility. Feeding is of
primary importance. Many newer punches merely use gravity as a feeder. A small
picker separates a number of sheets from a lift. They then fall straight into
the punch head, some on edge, some flat. They are then jogged and punched.
Static, curl and wave can, and will, cause a multitude of problems with this
method of feeding. Solving static problems is not easy and a strand of tinsel
will not fit the bill. The best method of feeding is a stabber/gripper system.
The stabber stabs into a lift of paper, then grips the smaller lift and pulls
it into the transport belts. This system is not affected anywhere near as much
by static or curl. Some machines offer an air feeder that allows users to feed
one piece at a time. This is especially important when feeding chip board or
signatures.
Registration is important for accuracy, but even more so for speed. A machine
that jogs on all four sides is ideal. Centering your sheet is an absolute
necessity. This means setting your side guide accu- rately, then setting your
other side guide. Sometimes you will have to run back and forth, from one side
of the machine to the other, a few times. There are machines that have a
micrometer, which actually moves the die back to save this step.
Some machines can only punch near the spine; some can punch anywhere on the
sheet. This comes in handy when punching windows, slots, wraparound covers,
etc. There is more to punching than double-loop wire and plastic coil patterns.
Make sure that your machine has jam-up detectors or that it can reverse if you
have a horriffic jam-up to save time and stock.
Delivery is another considera-tion. There are three main systems: A hopper or
jogger, a receding stacker or a conveyor. A hopper or jogger is fine, but
remember that if you are punching 6½or 7½ of paper per minute, that hopper or
jogger is going to fill up every 20 to 30 sec-onds. Most operators run their
punches slower because they can-not offload quickly enough or they have to use
two operators. Neither of these options makes the boss happy. Receding stackers
have a much bigger lift height, but the machine must be stopped, the stacker
offloaded, reset and rolled back into the machine before an operator is back in
production.
A conveyor, on the other hand, buys the operator time. He can con-trol the
speed of the conveyor so that he can offload it to meet his own speed,
irrespective of the machine's strokes per minute speed. Furthermore, the
operator can inspect the work after it is punched or, if he chooses to, go into
a jogger-after the conveyor. Either way, he has a choice, which results in
better versatility.
When looking to buy an automatic punch ask the following questions:
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What is the unit's maximum and minimumum sheet size?
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What is its speed?
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Does its delivery allow for the use of one operator?
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How does the feeder work?
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Can the machine feed signatures, booklets or board?
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How much paper waste can be expected?
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Are parts available for the machine locally?
Drilling more than 10 round holes in a sheet is counter-productive. At that
point, it pays to begin punching your holes. Multiple passes on drills can lead
to errors. The more passes, poten-tially the more mistakes.
Drilling holes for 4:1 plastic coil patterns is a fool's errand. Punch-es,
naturally, are more versatile since they can punch any hole shape. Drill prices
range from $5,000 to $20,000. Punches range from $8,000 to $50,000.
So, if you get away with drilling, keep drilling. One day you may hit oil.
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