jmeineke

Just a bit of red on the table - nothing that I can see on the body. It's pretty caked up with crud.

I did a quick wire brush of the sides and the top. I still have more cleaning to do but but here it is for now.. Can't find a name or any markings. The face is pitted pretty bad, but rebound is really good. Looks like a pretty thick piece of tool steel on top. Too bad they stored it in mud!

All drilled and put together. Thanks to everyone who responded - I really appreciate all the help. Ended up using a crucifix I had on hand for now.

Another member was kind enough to send me some bits that I'll be using for my next one and I'll be making some jigs and better tooling to make it go easier.

Well, here it is - finally finished it. I think it turned out pretty good. I may end up redoing the wire - I nicked it up pretty good in some places. I'll probably make a hand-made crucifix to put on it at some point, but for now I'm just using one I had on hand.

Thank you all very much for your help on this. It's been a heck of a learning experience.

It definitely has a 'Vulcanish' look to it. Is the pritchel hole potentially filled in? I have never seen a Vulcan without a pritchel hole.

Think I should pass? It has a mouseholeish look to me, but I don't know.

Been sitting outside. Paying about 75 cents / #.

I got all the beads drilled last night and am in the process of putting it all together. The crucifix is somewhat small and I don't have a centerpiece yet, but I'm thinking about making both from scratch.

I thought it might be kindof cool to incorporate some copper in a metal cross using a process like the vikings used to do - cut out a groove in the metal and then hammer the copper into it to make patterns (at least I think it was the vikings). Don't know if I'd be able to do something like that or not, but it would look cool.

OK, here is a thought: punch them cold or hot with a piece of piano wire, then heat and remove.

Feel free to call me nuts, I haven't tried this, however the coefficient of thermal expansion is greater for copper than steel.

http://en.wikipedia....ermal_expansion

Phil

Anyone?

I sometimes find it useful to make a holder for repetitive jobs so that the vise does not need to be repositioned each time. Once it's positioned for the first piece then all that is required is swapping out the parts, with an occasional accuracy check. A center drill or spotting drill works well to start the hole accurately.

Probably too late for this job and not apropos your bit breaking problem. Glad to hear it's going better.

I assume these are your forged spheres, if so an annealing/normalising cycle may assist before drilling them

Came across this 100# mystery anvil for a reasonable price and decided to go ahead and buy it. Might be a vulcan but I'm not sure. I'll be picking it up on Saturday.

Any initial guesses on what I'm getting? I don't see a pritchel hole - don't know if that helps or not.

I have worked with copper, and the shop I am the tool maker for now goes through literally tons of copper a month.

One thing no one asked is how well are they being held. It has to remain solid with no moving around, holding it by hand, or not snug in a vise will cause breakage.

Sharp vs dull or 0-rake. I have only flattened the edge when drilling brass, copper no. I have never had a drill grab in copper, but instead gall up with chips. For brass, and hand feeding, you grind the cutting edge vertically so that it is parallel with the shank. That way it scrapes instead of hooking.

I wouldn't use WD-40, use a motor oil/trans fluid, cutting oil,etc if you have it available. Being a thicker viscosity it will hang in the hole better.

The drills we run in the screw machines are razor sharp, and they get pulled at the slightest hint of dulling. We run solid in house ground carbide spade form drills, and HSS twist drills. Drills will last a lot longer cutting the berrylium alloys than copper. The copper will dull carbide faster than you would expect. For your application I would only use HSS drills, carbide will snap very easy if side loaded at all. Dulling them will also make you push harder causing breakage. Just peck the holes IE; drill till you see a small chip form than pull it out of the hole. Do not try for the long twisties, even if it seems to be going well. The other thing to watch is the breakout on the back-prime time to grab, and break. You may want to consider soldering them to a block, or make a sacrificial backer of some kind to eliminate the rounded breakout of the sphere. Each bead should use a new spot to breakout into.

Are you using a center drill/ pilot drill, or center punch? If you don't have a straight start you are doomed from the beginning. Drilling a sphere, or any round stock without a starter is not recommended.

Also use quality bits, not the cheapest ones at the big box store.

Speed- it depends on how well you can feed it, run-out of the spindle, and the drill bit. There is no set speed. Play with speed, and feed till it runs good, but 400 is way too slow, but 700 may run like a dream.1000 may gall up faster than you can clear the chips. But whatever you do keep the bit lubed at all times.

Feed-as mentioned before use a pecking cycle to get through these. If you are using a standard home drill press, do not use the handle in the the usual way. For small bits I will run the spindle down by gripping the center hub, not the long handles. By doing this I have less leverage, and less chance of bending a bit.

Keep us updated, and did I mention to keep the bit lubed?

You mentioned drilling a sphere, a standard jobbers length bit will want to wander trying to start it on a face that is not flat. If the drill is off center that could be causing your breakage. I would try a screw machine length bit. Oh and a lubricant.

Very interesting.

Well, I tried the high RPM (can't remember exactly what it was, but it was over 2000) and the bits broke even easier - even with pecking - but I wasn't using a lubricant as suggested (I reasoned that if I only went a very small amount at a time, a half second "peck" or so, that it wouldn't matter. I was wrong...)

Last night I experimented at lower speeds using WD-40 as a lubricant. As long as I kept it wet, I didn't have any breaking (I was going pretty slow, but had some nice long threads coming out of the hole before I pulled back to clear the flutes and re-lube). If it got too dry, though, the long threads would disappear, the bit would not feed right and it would break every time.

I'll kick the speed back up to around 2000 and will keep it lubricated. I like the soap idea too - I may give that a try. I have some beeswax I was going to try too, but at this point I'll stick to what I know works (I'm running low on 1/16" bits!). If I still have breakage I'll experiment with dulling the bits a little.

Quick Question - would I have better results with carbide bits? I know they are even more brittle, but would they handle this better?

I'm trying to drill 1/16" holes in 5/16" copper spheres and keep on breaking bits.

These are decent bits made of O2 steel. I've run them on the slowest setting I could (around 400 RPM) and was feeding very slow. I've had some successes but stopped trying after breaking 3.

What am I doing wrong? Shouldn't these be able to go through copper like butter?

Here's a chuck, under 9 bucks including shipping.
http://cgi.ebay.com/...=item35a9c730b7
You can probably find one at a local hardware store also.

A collet would do the trick if you can find one large enough for the drills you have.

Frosty the Lucky

Prayers going up from Ohio.

You can cannibalize a cheap or burned out hand drill to get the chuck and shaft. The shaft may have steps in it which should not be a problem for common small drill bit sizes.

Phil

There are small chucks sold with a short extension on the rear that can be gripped by a larger chuck.

I'm guessing this is a drill press 101 question, but here goes....

I have a clark metalworker floor model drill press that has a chuck that's too big for a small drill bit I need to use.

Do I need to buy a different chuck or do they sell adapters that would allow me to use a 1/16" bit in what I have? If so, what are the called?

Well done, 12 out of ten for determination, maybe you shold change your id to Perce E Vere! lol

Now you have solved this problem, and have the tooling, you could try this

Forge your bar to size, (slightly smaller than the finished diameter of the bar)

Cut off a piece the length of the diameter of the ball (Shear, saw or other)

Place this pellet in the bottom tool, and coin it in the tool, you should get a finished ball.

My Apologies, I totally missed this method at the start of the problem solve by classically ignoring the size of job in the first place, I should have known better and taken ALL the details into consideration, I must have had a Doh! moment.

If we learn by our mistakes, we learnt a lot here, Congratulations for sticking with it.

I decided to make a quick top die to use with the existing bottom finishing dies I welded to a small welding table. I made it out of some NAK-55 (not too hard or too soft at 40 HRC, easy to machine... been looking for an excuse to use it....). Anyhow, I'm pretty happy with the results. About 15 to 20 hits, rotating the bead after each whack, and they come out looking pretty good. I put them side by side with the rough ones for comparison. Second pic shows the dies I'm using for finishing - the two bottom dies are drilled to different depths (the second one tended to trap the bead until it was more rounded. The other die doesn't go down far enough to trap, but had the right curve to keep the bottom from flattening while hammering).

Thanks - this has all helped a lot.

Phil - no, they aren't holding up so well. That's my fault, though; I'm not doing this right, but on the upside I'm learning a lot.