Help! Layout tool help - Double headed prick punch

fat tony

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Some time ago, I am relatively certain I saw such a product being advertised for sale. The idea was if you were going to be making parts by hand out of flat stock, you would get the outline on the metal in your layout blue. then you would make a series of double punches around the perimeter of your layout lines. The outer row of punched holes made a convenient guide for your drill bit when you chain drilled out the rough shape. I can't find any online reference to this tool. I think it might have been sold by Brownells at one time, but this could have been some time ago. Does anyone recognize what this tool is, and if so, who is selling them. Thanks Tony.
 
I use a transfer punch at least 1/32 larger than the drill I will use, to scribe a "drill" line (and punch at the same time).
Works well for me.
Remember to hold the punch vertical or slanted out, but not slanted inward.
 
Reply #1 - not sure if we are on the same channel.

Reply #2 - not quite the same, but roughly along the same lines as what I was thinking.

When I input: "tranfer punch" as a query on a search engine, the types of transfer punches for transferring hole locations to underlying pieces come up. this is not what I am referring to.

From what I recall. the type of tool I was looking at had a second point with an offset, and might have been adjustable. I don't know the manufacturer or the part #. Not even sure who was the manufacturer, possibly British or American.

I found some reference material! :)

At the link below:

http://collections.infocollections.org/ukedu/en/d/Jgtz063ae/2.html

#3 is what I am referring to:

p08b.gif


Top row, 4th from the right:

$_57.JPG
 
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I can't help with the two pointed punch but I gave up chain drilling for such parts years back. I find that it's just far and away easier to use the metal bandsaw in vertical mode to cut around the outline then cut multiple "V" cuts in to just shy of the scribed line. The resulting small teeth are then cleaned up with files.

Time wise it's even faster than chain drilling and then cutting all the webs free. And I don't need to worry about wandering drill bits and lots of pushed through burrs.

Try it, you'll never chain drill anything again.
 
I have looked and looked. I don't have a Do-All bandsaw or even a cheapo craftsman bandsaw anywhere in my basement. A carbide rod saw blade & frame? Yes! Drill motor & drill bits? Yes! Double headed prick punch and unlimited $ to buy lots from Tool & Die maker estate sales? No! :)

Your reply does give me an idea though BCrider. After chain drilling, I will probably use a 4" angle grinder with a cut off disc to get rid of unwanted bits.
 
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Your chisels in the picture are mostly stone working tools, with a few assorted metal working chisels thrown in for good measure. Further, the fourth one from the right has 4 points, not 2.

Picky? Yeah. :)

A decent bench vise, a couple decent hacksaw frames, and a couple decent blades (I like Starrett blades, but anything that is not made from Chinese recycled rebar is good!) and some practice, and you'll never bother with chain drilling again.

For fine work, on not-too-thick parts, learn to use and appreciate a jewellers saw frame and blades, along with a bench pin.

I have seen all manner of devices that were meant to save time, that mostly just interfered with getting on with getting the job done. But a spacer arm, attached to an automatic center punch, might suit your need pretty well too. You plant the offset arm in the first mark, press down, rinse/repeat ad nauseum.

I can recommend some sharp files too. Most folks ruin them and then keep trying to use them, They are cutting tools too, and must be sharp. Surprisingly, most users seem to miss that they also have teeth all the way up to both ends! :) Same as hacksaw blades.

Cheers
Trev
 
you could cut a v in the face of a cold chisel with a dremel then grind both points with the dremel to suit your needs, or have a pal with a lathe turn a double punch in the 4 jaw chuck, I have seen others weld 2 punches together as well the big question is what drill bit size ? this will determine your centers
 
I'm with Trev. Having chain drilled and laboriously chiseled or reamed out internal holes I'd frankly just about be willing to do home surgery on my own spleen if I can avoid chain drilling in metal to cut out a part. For external cuts even a hacksaw is far and away preferable and doesn't take long if you have a new or good condition blade.

But really, if you do more than a half dozen metal related frabrication projects a year you NEED to buy one of these.... This particular one is only $320 at Busy Bee Tools at the moment. Trust me, after trying to do this sort of work with hacksaws, files, chain drilling and cutoff discs you'll grin like a kid with with a bucket of ice cream and a big spoon every time you use it.

b013n__94929_zoom.jpg
 
I'm with Trev. Having chain drilled and laboriously chiseled or reamed out internal holes I'd frankly just about be willing to do home surgery on my own spleen if I can avoid chain drilling in metal to cut out a part. For external cuts even a hacksaw is far and away preferable and doesn't take long if you have a new or good condition blade.

But really, if you do more than a half dozen metal related frabrication projects a year you NEED to buy one of these.... This particular one is only $320 at Busy Bee Tools at the moment. Trust me, after trying to do this sort of work with hacksaws, files, chain drilling and cutoff discs you'll grin like a kid with with a bucket of ice cream and a big spoon every time you use it.

B013N__68250.1419017196.1280.1280.jpg

Just got one of those for the first day of hanukkah.
 
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I think I get your point but the picture shows a cut off saw. Anyways, I guess I am missing the point wrt cutting out parts. Might just use some drills to form the concave curves then use other means to cut out the convex curves.

It can also stand up and be used as a vertical bandsaw. In fact they were often listed in the write-ups as horizontal/vertical saws. I can understand your lack of enthusiasm given that you apparently didn't realize that it can be used in the vertical mode.

I've show three photos of mine below. First is shown in the cut off mode you already know about. Second is in the vertical mode. And the third is a closer in view of the small table I added to make using the vertical mode easier.

The roughly 4 x 5 inch table with the corner cut away as shown is all I need for steadying stock as I free cut it with the power unit standing up. The table size and shape shown allows me to leave it in place when doing cutoff work. It could be a little larger but it was a piece of steel I had at the time. And the size shown worked out so well that I've never felt like the effort to make a larger table was worthwhile.

First shot in cutoff mode-
P1020172.jpg


Vertical mode-
P1020173.jpg


And a closer in view of the auxiliary table I made for it-
P1020174.jpg
 
BCRider I have the same saw,it has totally impressed me with its cutting ability, I could not begin to count the amount of cuts it has made 30 bucks for a bi metal blade that seems to last forever if I don't kink it
 
Tony, room is a different issue. Can't help much there.... :D But when you're ready at least this gives you an idea.

Aklavik, I've had mine for about 15 to 20 years now. I'd rather give up a duplicate body part then this saw. Or rather the ONLY thing that would push it out the door would be buying a nicer and bigger saw. But then many/all of the larger saws are horizontal only. So I guess this one and I are stuck with each other.

There was one project where I wanted to make a new tool post for my lathe. I used this baby to cut off a hunk of 4x4 steel bar. It took over an hour as I wandered around doing other things but eventually there was a large thump as the chunk fell off into the waiting box full of cardboard scrap.
 
Hmm - I can visualize what you're talking about. Never actually seen such a tool, but wouldn't be hard to make.

Find some suitably hard worn down chisels, grind to shape using a grinder or dremel without overheating (lots of short grinds with long dips in a cold tub of water in between) and make several sets of varying width's for various projects. A sharp taper at the point would be best as you're trying to just mark rather than displace lots of metal. Also won't bend or mushroom as much. Not sure exactly what hardness you'd want, but I suppose as hard as you can get without causing the tool to crack or chip when used. If you've got access to a torch and have the fundamentals of hardening/tempering you'll have more options on how to go about the process and how much control you have over things.


Thinking things over more... if you're offsetting the punch already for drilled holes, you don't actually need a double headed punch, since you won't be drilling the actual profile. As such what you really need is a single pointed punch with some kind offset or adjustable offset to consistently keep you a set distance off the line you're following. Maybe a piece of thin spring steel with a stylus on the end? Punching would cause it to jump but not actually put any pressure on it, and it wouldn't obscure your view of what you're tracing.

End of all this, you'll still have to keep the whole thing 90* off the line you're following or there's risk of the bit cutting into the profile if you're keeping relatively close to the line with your bit. Still, should work given the limitations of everything!
 
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