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Disk cutter use


#1

Here’s another request for guidance, What is the proper way to use a
disk cutter? I am having a lot of trouble and must be doing something
wrong. I actually damaged one of the punches and still am not
completely sure why.

When punching disks, what is the best tool to use to hit the punch
with? I have tried an 8 oz. dead blow mallet, a 16 oz. dead blow
mallet, and a hammer. The mallets do not push the punch though on the
first blow, and the metal is disloged so I do not get a clean cut. The
ball peen hammer ( I’m not sure how heavy, maybe 16 -20 oz) goes
through with one blow, but deforms the part of the punch that it
strikes. I think that’s how I messed up the hole, as the end of the
punch was damaged, and when I pushed it all the way through to the
other side, it must have damaged the cutter block. Then, of course,
when I attemped to cut another disk of the same size, the damaged
block cut into the punch and messed that up too. I now do not push the
punch through to the other side, but push it back out the same side I
hammer it from, using a pin punch.

I had some success with 22 gauge sheet, but want to use 20 gauge as
well. Can anyone offer some tips or advice on the proper use of this
tool?

Gail Middleton


#2

I use a heavy steel hammer to hit my disk cutter punches. I place it
on a piece of wood so the punch won’t be damaged if it goes all the
way through. I also anneal the metal first which makes a big
difference. Use a heavy enough hammer that one strike will punch the
metal if possible.

–Vicki Embrey


#3

This works for me

1 I always place the disk cutter on a wooden base. A steel or hard
surface underneath will blunt and/or deform the cutting edge

2 If possible I always “overhang” the hole that I’m using to cut so
that there is nothing underneath it. This way the follow through is
clean. Put a soft cloth ot something similar underneath so that the
punch does not fall on a hard floor.

3 I’ll use any hammer on hand that won’t be damaged by the steel
punch. Rawhide, deadblow - it doesn’t seem to matter.

4 I try to ensure that the hole, sheet and punch are scrupulously
clean!

5 Holding the sheet in place with the fingers of the hand that are
holding the block ensures it does not shift.

Tony Konrath
Gold and Stone
www.goldandstone.com
tony@goldandstone.com


#4
  Here's another request for guidance, What is the proper way to
use a disk cutter? 

Dear Gail, I don’t completely understand your explanation since a
disc cutter punch has one end for cutting and the other for hammering
on. Unless you put it in upside down and hammered the wrong side, I
don’t see how you could have damaged it.

Anyway, I cut discs frequently and I use a chasing hammer since it
has a large flat head (less likely to miss the mark), but any metal
hammer will do as long as you hit a sharp, crisp blow. I make the
initial hammer strike to cut the disc and then I move the cutting
block halfway off the bench surface so that the disc falls out and the
cutting edge of the punch never comes in contact with the bench. In
other words, as the punch is hammered out the bottom end of the
block,
the punch is hanging in air. (I pull out the center shelf of my bench
and the filings drawer to catch the disc and the punch as they fall.)
I do use a smaller pin-type punch to hammer out the cutting punch
once
it is flush with the top surface of the block. If you turn the block
upside down, however, and use a pin punch to push the cutting punch
out the top of the block, you could easily damage the cutting punch
with the pin punch. I hope this makes sense since it’s hard to
describe in words. As they say, “One picture …”

One more thing. If the discs you’ve cut have a flange of metal on
the edge, it is probably due to a badly made punch/block set. A
friend once had to return a disc cutting set for this reason; one of
the holes was a little too big and she couldn’t get a clean cut. When
the punches fit their respective holes perfectly, every disc you cut
should have a clean edge.

Beth


#5
    Here's another request for guidance, What is the proper way to
use a disk cutter? I am having a lot of trouble and must be doing
something wrong.  

G’day Gail Middleton and others. The hollow punches which are what
I
assume you are using to cut discs from sheet metal are really made to
cut discs from fairly soft materials. Indeed, I have seen them in
tool shops under the heading of ‘wad punches’ because they used to
be
used to punch out the little felt discs called wads used by shooters
to separate shot from powder in a gun, and to stop the shot from
moving
about.

I don’t of course know what size discs you need, but I have made
many
discs up to 12mm diameter easily from 0.5mm sterling sheet. I use a
punch and die approach.

Firstly get a rod of carbon steel of the same diameter as the disc
you need. Cut off a piece about 10 cms long. Grind one end dead flat
and square to the axis and sand to 400 grit semi polish. Heat just
that end to red heat and quench in cold water, swirling the rod about
as it cools. Now get a piece of mild steel rod about 25mm long and of
a diameter enough to drill a hole through the length of an exact size
as the punch-rod, leaving some room at one edge. It is more accurate
to firstly drill the hole slightly smaller, then finish with the drill
of the right size. Make a hacksaw cut transversely through the metal,
at a right angle to the hole, right to the opposite side of the hole
to make a slot for the introduction of the piece of silver sheet. Now,
using a slightly bigger drill, open the hole about 1 - 2 mm deep at
one end. To use, simply stand the die on a hard flat surface, insert
the piece of metal to be cut right into the slot, put the punch into
the hole and give it a good bash with a fairly heavy hammer. This
will cut a clean disc which will fall free when you lift the punch and
die, because of the slightly widened part of the hole.

Finally if you really can’t get high carbon steel rod, email me
direct and I’ll tell you how to case harden a mild steel punch
sufficiently to produce 20 - 30 discs.

With a picture I could have cut this rigmarole by half, but if you
find the above a bit confusing and would like a picture, I’ll scan one
of my die and punch units and email you direct. Meanwhile, I hope I
have managed to punch home the general idea. Cheers, –

John Burgess; @John_Burgess2 of Mapua Nelson NZ


#6

Ive had deforming and double jumping too. Now I line up the punch
and metal pieces then put them into my vice, slow but smooth. karen


#7

In John Burgess’s last posting on this thread, he explains a method
of disc cutting using high carbon steel rod. In case anyone would
like a U.S. source for this material (as well as all kinds of tools,
tons of configurations of several different metals and plastics, and
lots more), check out Small Parts, Inc., (800) 220-4242,
www.smallparts.com, parts@smallparts.com. I haven’t checked out the
web site but the catalog is great.

Beth


#8

I wasn’t going to chime in on this, but didn’t see that anyone else
has made this suggestion. For any kind of punch, whether disk cutting,
quality marking, etc., I use a big fat brass hammer. The brass is
softer than any steel punch, and will always be the sacrificial
surface. Good, hard, heavy punch hammer. Give it a try… available
from most suppliers at a reasonable cost.

All the best,

Dave
Dave Sebaste
Sebaste Studio and
Carolina Artisans’ Gallery
Charlotte, NC (USA)
dave@sebaste.com