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crooked holes


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Hello all,

I am new to the forum and blacksmithing as well. I have been attempting a few projects but keep running into the same problem of when I punch a hole then expand it, it tends to go off to one side or the other.

does anyone have any tips or techniques I can read up on to keep the hole inline with the rest of the work, I know I have to try to punch the first hole as close to center as possible. here are some pictures to show the problem.

easier to see in dog picture then railroad spike

any help appreciated.

poundhound



In addition to all the above it is easier to keep a long tool perpendicular to the work than a short tool. If the tool is too long then you will tend to hit the driven end on the edge- don't do that. I wear a welder's gauntlet on my left hand to hold the tool when working larger stuff (hammers and such).

What you are doing now is teaching your body how to do the work- building "muscle memory". Eventually, you will think at the fire and act at the anvil.
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Just an update,

I made a new punch and tried to make it like the punches shown in "slitting Geometry" (sorry I don't have pictures will post some when I get home tonight) with a taper on all 4 sides and pointy at the tip. It punches the first side very easliy, leaves a nice deep mark.

the problem seems to be when I try to punch back from the other side it leaves a mark the same on the other side, but flattens out the first side. I kept going back and forth. finally I used the old flat punch I was using to punch out the plug (after a few go arounds).

Is it too sharp? is the metal too hot, does it need to cool some? any thoughts appreciated.

PoundHound

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Just an update,

I made a new punch and tried to make it like the punches shown in "slitting Geometry" (sorry I don't have pictures will post some when I get home tonight) with a taper on all 4 sides and pointy at the tip. It punches the first side very easliy, leaves a nice deep mark.

the problem seems to be when I try to punch back from the other side it leaves a mark the same on the other side, but flattens out the first side. I kept going back and forth. finally I used the old flat punch I was using to punch out the plug (after a few go arounds).

Is it too sharp? is the metal too hot, does it need to cool some? any thoughts appreciated.

PoundHound


Not being clairvoyant and knowing the sizes of your slitter and material and angles of points on slitter, I would take a guess that the metal you are trying to slit through is not thick enough to allow the slug to be pushed through the sheared portions of the parent material.

You could try using a bolster plate to allow you to push the slug out clean
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Are you trying to slit thin metal? And are you doing it over the hardy hole?



Not being clairvoyant and knowing the sizes of your slitter and material and angles of points on slitter, I would take a guess that the metal you are trying to slit through is not thick enough to allow the slug to be pushed through the sheared portions of the parent material.

You could try using a bolster plate to allow you to push the slug out clean


the metal is a 1/4 inch steel bar, and same problem on 1/2 inch thick end of a railroad spike. I am doing on the anvil (not over hole). I seem to get a good 2/3 through the metal, I seen the flat spot on the other side. then I hit the flat side and get what seems to be a good indentation, but when I look at the first side, the metal is flat again, not a punched out plug.

the punch is 3/4 inch in length and 3/8 in width (will post pictures tonight).

PoundHound
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After spending the weekend with Brian a few weeks ago, I think I can say that the angle of your grind is far too steep for using with thin stock. The grind needs to be about 1/3 or so of the thickness of what you are punching. The grind is just there to keep it tracking straight, and to help it plow through a bit faster. The grind you have is making it act more like a chisel than a punch. Brian's Punches are pretty much a traditional punch but with a very shallow angle to the grind. If I had my camera handy, I could take a few pics of the ones I have made based on Brian's tools.

Oh! And on a side note: Brian, I have almost completed duplicating your coffee can of punches you brought up to the WRABA conference... Now I just need to make me a big hammer like yours. Don't suppose you want to lend me one till I can get down there this winter to make one with you? LOL.

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You also want to punch until you feel the anvil, meaning the point when you suddenly feel a more solid mass through your punch. Then turn it over, hit it with your hammer, turn it back over hit it another time with your punch, turn it back over, find the middle of the black spot,mark it with a light blow etc... ( all is described in this video )

..... once you have done lots of punching, it becomes much easier to guage the middle and you can sight it straight off! All you need is practise, and also, the shape of your slot punch isnt the most desirable shape... i wil take a pic of the grind on a slot punch design ( brian brazeal's design) that works very well!

alec
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