Author Topic: THREE FACET PRICKPUNCH  (Read 2873 times)

Offline ieezitin

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THREE FACET PRICKPUNCH
« on: July 04, 2016, 10:04:22 AM »
Hello lads..

I found this trick on Tony's website and it works perfect...

its really annoying to watch a drill bit wobble on the prick mark / center punch mark just as your about to plunge it in the work, sometimes it wonders off and bores off mark and ruins your work, to solve this problem grind three facets on the punch on a 30 deg angle... i used this old punch and recycled it for this purpose......


























Loads a money........


Anthony
If you cant fix it, get another hobby.

Offline JHovel

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Re: THREE FACET PRICKPUNCH
« Reply #1 on: July 04, 2016, 10:36:12 AM »
Interesting.
Does it work any better than a round conical one?
If so, why?
Cheers,
Joe
Cheers,
Joe

Offline ieezitin

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Re: THREE FACET PRICKPUNCH
« Reply #2 on: July 04, 2016, 10:53:39 AM »
I have no idea why this works, my results have been very satisfactory compared to the conical punch, try it yourself and let us know what you find.

Anthony.
If you cant fix it, get another hobby.

Offline chipenter

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Re: THREE FACET PRICKPUNCH
« Reply #3 on: July 04, 2016, 11:02:03 AM »
Same as a watchmakers countersink never chatters , great for deburing holes .
Jeff

Offline Lew_Merrick_PE

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Re: THREE FACET PRICKPUNCH
« Reply #4 on: July 04, 2016, 12:47:15 PM »
I was taught (back in the Dark Ages) to first use a Prick Punch (with a 60 included angle at the tip) and then use a Drill Center Punch (with a 130 included angle at the tip).  [Mind you we used 135 included angle drill bits exclusively.]

Offline DavidA

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Re: THREE FACET PRICKPUNCH
« Reply #5 on: July 04, 2016, 12:53:29 PM »
The following may be helpful here.

https://www.youtube.com/watch?v=Ot8wPGQW3JI

Dave.

Offline velocette

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Re: THREE FACET PRICKPUNCH
« Reply #6 on: July 04, 2016, 09:05:33 PM »
Hi
One thing I was taught in the distant past was to file off flush with the surface was to use a thin warding file remove the burrs

Eric

Offline Imagineering

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Re: THREE FACET PRICKPUNCH
« Reply #7 on: July 05, 2016, 06:53:31 AM »

If you do this to a piece of Carbide and make the angle steeper, it works as a perfectly good engraving Tool in a CNC Setup.

Offline Pakrattuk

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Re: THREE FACET PRICKPUNCH
« Reply #8 on: August 16, 2016, 12:45:30 PM »
I remember hearing from a jeweller friend who was working with stainless steel at the time that a 3 sided centre punch like the one shown, was ideal for stainless steel as the sides produced by the punch gave the drill something to bite into as opposed to a round punch mark which could often lead to the drill spinning and work hardening the stainless, I've used this type of punch anytime i'm drilling stainless steel and rarely have any problems