how would YOU make these?

I go to 12-step meetings. Sometimes they hand out coins to commemorate
years of abstinence. For a long time I've had the idea of making a
keyring which would be bored to just hold one of these coins. I finally
worked up a design which I've figured out how to make from sheet brass:
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I make these manually on a milling machine. If there's a better way to
make them (absent CNC equipment) I'd love to know about it. It basically
boils down to a tricky workholding problem. I have a solution, but I'm
wondering if there's a better one. Thus the question: how would you make
these parts?
The dimensions aren't particularly significant, but the large hole diameter
is 1.354" and the small hole is a #10 hole. The brass is 1/8" sheet brass.
Sorry for the fuzzy picture.
Grant Erwin
Kirkland, Washington
Reply to
Grant Erwin
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Drill the holes in a piece of sheet brass which will make several parts. Easy to clamp. Ream the major holes to size. Cut out each part on a scroll saw. Finish by hand as req. JR Dweller in the cellar
Grant Erw> I go to 12-step meetings. Sometimes they hand out coins
Reply to
JR North
Where do you get a 1.354" reamer? I'd love to ream the holes, but ..
JR North wrote:
Reply to
Grant Erwin
Grant,
I would stack about twenty sheets of brass and bore the #10 hole then bolt the whole stack together.
Machine all at once as if you did one
Dan
Grant Erw>
Reply to
Dan
Greetings Grant. As others have said you can drill 'em and stack 'em. Absent cnc if you have a rotary table you can stack several rectangles that have been drilled and bored and profile the round part. Cutting a bunch of rectangles and boring them also has the advantage of keeping the burrs small on most of the pieces. With no rotary table you can bolt them to a bar that has a pivot on center and swing this bar on the pivot past the cutter. Make sure you make a conventional cut. The pivot hole should be in a plate with two other holes drilled in it with stop pins in the holes. These pins limit the rotation of the bar. BTW, if you show at the pig roast this year we have folks show up for pig who also go to meetings here on the island. ERS
Reply to
Eric R Snow
Grant,
It's in between the 1.353" reamer and the 1.355" reamer in my set. Your set isn't complete?
Peter
Reply to
Peter Grey
I would use a cold header stamp machine.
A place I use to work had dozens of these, stamping out connectors. Usually each machine could put out 100,000 pieaces in a couple of hours.
my 2 cents
Reply to
xman Charlie
MSC has a 1-3/8 reamer. Anybody with a cylindrical grinder can reduce it to 1.354 It might make more sense to spend the money on an adjustable boring bar. That would be more useful for other projects.
Reply to
Chief McGee
I use a boring head now. With practice, I can get within a thousandth of what I want that way.
Grant
Reply to
Grant Erwin
the question: how would you make
Well, you asked. I don't have a milling machine. I would start with a bar, shape the outside profile with passes in the milling vise and a file, chuck it in the four-jaw, drill and bore the holes, and cut them off like washers. If I had a mill, I would shape the bar with shaped cutters(I'm thinking horizontal here) or mount the bar in index centers and take multiple passes to shape. In the mill, you could mount a saw on the spindle and slice them off like cordwood.
Kevin Gallimore
Reply to
axolotl
Adjustable reamer...of course JR Dweller in the cellar
Grant Erw> Where do you get a 1.354" reamer? I'd love to ream the holes, but .. >
Reply to
JR North
Lasercutting Northwest in Auburn. Well you asked!
Reply to
Ernie Leimkuhler
I'd looking into have a bunch made by water jet down at the local sheet metal shop. R. Wink
Reply to
R. Wink
Same as I was thinking, or waterjet.
Lane
Reply to
Lane
How accurate are parts cut by laserjet or waterjet? If for example a hole is specified to 1.000" does it need to be cut slightly undersized and then reamed, or can they cut it within .001"?
Grant
Reply to
Grant Erwin
I have no first hand knowledge, but have heard that it is very accurate. The width of the laser beam and/or water stream is very precisely known and controlled.
I'm sure someone with more intimate knowledge will chime in.......
Lane
Reply to
Lane
Depends on the material and thickness and, like anything else, the machine and the operator. I've had parts laser cut from 11ga SS with holes burned in that were then tapped 6-32. The first batch I called the holes out undersize and then cleaned them up with a drill. After seeing how close to the print they were, had the rest cut to size and had no problems. I don't recall exactly, but they were better than +/-0.005 on a .107 hole.
Ned Simmons
Reply to
Ned Simmons
Omax claims +/- .002 for any 12" movement with a repeatabilty of +/- .0013. This will vary some depending on material thickness though.
Craig C. snipped-for-privacy@ev1.net
Reply to
Craig
They used a flowmaster (?) on AmericanChopper and Vinney found the cut was slightly angled which required some grinding on the part to make it fit. Not sure if that's a setup issue or just a feature of the tool. If so, I wouldn't call it accurate.
Joel. phx
Reply to
Joel Corwith
Check out the Omax tutorials on water jet technology.
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Seems to have been written by someone that loves what they do, instead of the typical marketing BS you get.
One of the topics covers tapered cuts and how to avoid them. Very interesting stuff :)
Take Care, James Lerch
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(My telescope construction, Testing, and Coating site)
Press on: nothing in the world can take the place of perseverance. Talent will not; nothing is more common than unsuccessful men with talent. Genius will not; unrewarded genius is almost a proverb. Education will not; the world is full of educated derelicts. Persistence and determination alone are omnipotent. Calvin Coolidge
Reply to
James Lerch

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