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dickb

Locating Center of round stock

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I have some 2 inch round stock that I want to use to make a hammer.

I expect to slit and drift the eye. but I don't know how to accurately locate where to begin slitting. 

Can anyone suggest a way using basic hand tools ? 

I think maybe I could wrap a quarter inch strip of paper tightly around the stock and then then use a pin to pierce through the paper where it overlaps itself. Then cut it off at each pinhole and fold it in half and mark the center of the strip with a pinhole. Finally tape the strip back on the stock and center punch at the end of the strip and also at the midpoint of the paper strip. 

I am pretty sure this would work, but is there a better way ? 

In addition, how do I begin the slitting, that is how do I assure that the stock is properly positioned with the center punch mark at the exact top of work when I begin slitting.  We should assume that the ends of the stock are a little irregular. 

It's a big piece of steel and I want to get right the first time. 

Edited by dickb
left out some pertinent information

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Seeing as you don't have a centering square or "Pi tape." The easy way is wrap a piece of paper around the bar and mark the point they overlap, remove the paper and fold it in half so the end and the mark are in contact and crease the fold. Now when you wrap the paper around the bar again the end and the crease will be directly across from each other.

This can be done to equally divide a cylinder in quarters, thirds, etc. 

Frosty The Lucky.

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You Know Frosty sometimes you Forget the Simple way to do things

and then Do It the Hard way !! LOL

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I was shown to take the piece, heat it in the forge and give it a few taps on the the length on the anvil. This gives you marks evenly across from one another. ( one side from the hammer, other from the anvil.) Then mark your center length on each of these and have at it. 

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Greetings Dick,

           Take your round stock place it on your cut off tool cold ... tap tap tap  ( small mark )  than turn it over visually center the mark and tap tap tap ...  normally this is more than accurate for punching ..  ( good ol boys way ) .. Good luck

 

      Forge on and make beautiful things 

Jim

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Center of the circumference is one thing, center of the length is another.

Balance the length of cold stock on the edge of the hot cut or edge of a piece of angle iron. Tap it with a hammer to make a mark.

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dickb, here is a center finder woodworkers use, but you could make one for smaller stock.  These are usually 6-12" in diameter for the woodies.  Just rotate it around to several places and mark your center line.  Intersection is center.

 

Center finder for round stock.bmp

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Clamp your round bar to some heavy angle iron, "then drill (2) 1/8" holes to mark the slit.,,,  or use square stock.  

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On 8/18/2018 at 11:20 AM, IronWolf said:

You Know Frosty sometimes you Forget the Simple way to do things and then Do It the Hard way !! 

Do I do it the hard way? I'm ALWAYS up for learning a new trick!

Marking opposing sides on the anvil requires a person to make a blow directly down through the center. Finding the center lengthwise is just a matter of measuring and marking. 

Frosty The Lucky.

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Not you LOL I was just saying most folks I tend to ever so often do it the hard way then look @ it Then the Brain /? asks why did we just do that way instead of the Easy Way LOL :wacko:

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You have it wrong,,,  first do it the hard way, then figgirr out an even harder way!  don't waste all that "hard" earned experience!!  ;)

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Get a 2nd bit of stock similar diameter,  lay them side by side, get a straight edge  and scrape over the top of the 2 lengths, This will give you a center line to measure on. Over 30 years I made 1000's of sand blasters made from tube, worked every time.

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I usually find the center of the horizontal run of round stock by clamping it in my drill press vise with a v-block, bring the chuck down with a small drill bit and mark it.

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I have a combination square with a center head on it that allows me to scribe a line on a diameter across the center.  Doing it from 2 or more angles nails down the centerpoint.

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The center of the end is low tech easy peasy. Brush the bench off so it rolls smoothly, hold a piece of chalk a dirty hand, etc. against the end and roll it on the bench. Eyeball it, the center is clearly visible.

Frosty The Lucky.

 

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21 hours ago, Irondragon Forge & Clay said:

clamping it in my drill press vise with a v-block

My way as well, altho I often use a piece of angle iron as a vee block

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Use a drill vise!? :o Sure and next you're going to tell EVERYBODY the drill bit will contact the highest point and be aimed straight through the center! Whatever you do don't let out the old timy trick of chucking up a center punch in the drill press so when you locate center you can just give it a bump and center punch the spot, replace the punch with the drill bit and drill the hole. 

I use angle iron as a straight edge to chalk or scribe lines straight down round stock as well. Since we're giving all the tricks to make this stuff easy, why not that one too? ;)

Frosty The Lucky.

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I've never chucked up my center punch. I'll remember that!

Angle iron as a straight edge I have done. A great one to mention.

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On 6/21/2020 at 11:16 AM, Frosty said:

Use a drill vise!? :o Sure and next you're going to tell EVERYBODY the drill bit will contact the highest point and be aimed straight through the center! Whatever you do don't let out the old timy trick of chucking up a center punch in the drill press so when you locate center you can just give it a bump and center punch the spot, replace the punch with the drill bit and drill the hole. 

You can also use a tap to line up on a mark in the drill press. Or any accurately pointed object like a center punch (I hadn't ever thought of that) if it is really straight and ground true.

For cross drilling in the drill press, to accurately line up the stock in a vee block or vise, take your 6" ruler, put a tap or other accurate conical item in the chuck, touch the point on the center of the ruler, and adjust the stock's position until the ruler is parallel with something horizontal - edge of vise, table, etc. Then clamp the work or vise down, recheck the alignment, then drill.

Note you need to know the table is square with the spindle, and you need to know the spindle is pretty straight.

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Unfortunately taps ARE brittle and hitting one in ANY way is more likely to chip the tool. Center punches are impact tools, taps and dies aren't, they are cutters. 

Frosty The Lucky.

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Good point maybe that was unclear to others. You make the center punch or mark away from the drill press. The tap is ONLY because it has a reliable point on it, to visually align the spindle to the desired hole location. Light pressure on the quill can be used for the ruler trick.

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If you have the necessary shop skills to place the center punched round stock in the vise with the punch mark directly through the center of the stock. I've been doing that level of precision work since before I left elementary school and even have instrumentation to do it to the 0.00001".

Center punching round stock can leave a punch mark itself that is off and can itself cause the drill bit to walk. The same shape punch mark you get if you hold the punch at an angle when you strike it. 

Using a center punch in a drill press and scratching to mark the top of the cylinder and a gentle bump on the quill in no way abuses the: punch, quill, drill vise nor drill table but produces a mark to start the drill bit without it walking and allows a person to drill and tap a hole in round stock as accurately as a non-machinist with a high end drill or mill can reasonably expect.

This is NOT a machine shop trick, it's a modest level home shop trick.

Frosty The Lucky.

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Another trick I use to center and drill round stock without the bit walking is to file a small flat spot on the stock, small enough for the center punch AND drill bit to still make good contact.  The bit will be much less apt to walk on the small flat surface than a round one.  Depending on the bit size, sometimes the hole will completely "cover" the flat spot for lack of a better word.

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Here's a good video covering a variation of Frosty's center punch in the drill press trick, which I've never used but will try.

 

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