Finding center of 1/2" rod?

[Wayne Smith]

For the machinists out there I know that there must be some easy way to find the center of the end of a 1/2" rod. Remember, I'm a psychologist, I don't have that education.

I am at the point of drilling 1/2"x1/2" brass rod to make powder bushings for my Pacific Pistol Powder measure. My first attempt was with a #27 drill, a consistent 1.2gr BE. I PM'ed Froggie about that, if you remember his attempts to load his 32 Short. I'm doing the same thing, so that was a blessing.

It was vastly off center - but doesn't matter for that small. When I get to bigger charges I need to be very closely centered. How? Is there a spring loaded gadget that slips over the end of the rod and pull and let go and - wammo - a centered mark?

[HollowPoint]

I would generally draw a 1/2" by 1/2" square on a piece of paper.
I would then cut out that square and slip my 1/2" rod into it.

From there I could then draw an X from corner to corner of my newly drawn 1/2" square.
That should give me the exact center of my 1/2" round stock.

P.S. I'm not a machinist or a psychologist. I'm an auto upholsterer.

HollowPoint

[bruce drake]

I would generally draw a 1/2" by 1/2" square on a piece of paper.
I would then cut out that square and slip my 1/2" rod into it.

From there I could then draw an X from corner to corner of my newly drawn 1/2" square.
That should give me the exact center of my 1/2" round stock.

P.S. I'm not a machinist or a psychologist. I'm an auto upholsterer.

HollowPoint

Or use a Metal Triangle to draw bisecting lines on the end of the round stock.

[theperfessor]

Wayne -

I have a spring loaded punch that is OK for making enough of a dent to start a real punch, but I think there is something better for your purposes. The URL below is to the Enco page that shows transfer punches. These are designed to fit into an existing drilled hole and when you hit them they mark the center the hole on the piece underneath. Used to mark the holes on cover plates and other items that must have holes that line up.

http://www.use-enco.com/CGI/INPDFF?PMPAGE=766&PMCTLG=00

Then you get a short piece of material with a 1/2" hole in it and put it over the part and the punch and you should get near perfect alignment.

For what its worth I got my set of punches at Harbor Freight for less than $10. And if you can't find a rod with a 1/2" hole just holler and I'll make you something.

[Chicken Thief]

I use one of these:

https://www.google.com/search?q=center+finder&hl=en&client=firefox-a&hs=LK1&rls=org.mozilla:da:official&source=lnms&tbm=isch&sa=X&ei=iIIrUa3-DtCSswb28oFo&ved=0CAoQ_AUoAQ&biw=1280&bih=699

[ranger1962]

old time speed square aka small carpeters square had an attatchment that was a center finder.
You can sometimes find them at hardware stores either in the $5.99 tool ben for the plastic one or
they should have one on the isle with the rest of the squares.

[Wayne Smith]

I have a carpenter's square. That is fine for finding center for wood lathe work, not accurate enough, at least in my hands, for 1/2". Thanks, Keith, I'll look into that.

[waksupi]

If you chuck it in a drill, spin it with some sand paper held to the end, you will be able to see center.

[oldred]

If you chuck it in a drill, spin it with some sand paper held to the end, you will be able to see center.



You beat me to it, that little trick is easy and works like a charm!

[Wayne Smith]

Yeah, the problem is then marking that accurately and transferring it to the drill press with the mark!

Turns out I already had exactly what I needed. Thanks for the idea, Keith. I have an adjustable tail stock insert for my wood lathe that is exactly what you described, a holder that is just over 1/2" and a sliding pointed piece that is centered in it. Once I got that picture in my mind I knew I had it, just had to find it and make sure it was the size I remembered. It is.

[RayinNH]

If the pieces are short, chuck them in the drill chuck. Now take a drill and put it in the drill press vise sticking point up. Eyeball for center as best you can. Turn on the drill and lower the chuck until you contact the drill with your work piece, it will find center and you can continue on drilling until you break through the other side. Think of this as a vertical lathe...Ray

[Cap'n Morgan]

+1 What Ray says...

If you use a short stub drill and only leave a little sticking out of the vise, you'll get a perfect center.

[leftiye]

Most impressive guys! Kudos.

[theperfessor]

Good deal Wayne!

[gkainz]

For the machinists out there I know that there must be some easy way to find the center of the end of a 1/2" rod. Remember, I'm a psychologist, I don't have that education.

As a Psychologist, you should know that you just have to convince the rod that it WANTS to be centered!!!! :) sorry, couldn't resist ;)

[arjacobson]

Clamp a short pc of 2x4 to your drill press. Use a 1/2 wood bit and bore a hole. Without moving the table take the drill out. Put in the size drill you need. Insert the rod into hole bored through block. If the rod is long it should still fit through the center hole of the drill press table. If the rod is short just drop it in. Should be close enough for what you are after..

[Junior1942]

If the pieces are short, chuck them in the drill chuck. Now take a drill and put it in the drill press vise sticking point up. Eyeball for center as best you can. Turn on the drill and lower the chuck until you contact the drill with your work piece, it will find center and you can continue on drilling until you break through the other side. Think of this as a vertical lathe...Ray

HOW does it find center???

[RayinNH]

Junior I guess what is happening is the drill is trying to find the path of least resistance, which happens to be the center when the piece is spinning. If you have watched a lathe in operation the work piece is turning the drill is stationary. Even with some slop in the machine it will find center...Ray

[John in WI]

I'm worse than a psychologist--I'm a chemist! But the idea of spinning it in a chuck and scuffing it with sandpaper sounds like an excellent one. It should look like those time-lapse pictures of the North Start? All the scratches swirling around--except the one point in the exact center of the movement. I'll have to put that trick in the tool box.

[Wayne Smith]

That actually works well if you are not going to move the workpiece. I use it on the wood lathe all the time. In this case I'm cutting 1/2" pieces off the rod and needing to center them.

Of course, I just realized that if I mount the stop collar on a longer piece of wood, mount a piece of center drilled brass in it, lower the drill into it and clamp the wood to the drill press table; all the others will be centered!