Best Way To Make This?

[DroopyPawn]

I posted pictures on another forum of a part I need to make multiples of for someone. Here's the site with pictures.

http://bb.steelguitarforum.com/viewt...051805#1051805

What would be the best way to make this part?

Obviously, the original is made of 3 welded pieces - a ring sandwiched between to like pieces. I was considering milling the piece from one 3/8" thick piece of 6061.

I can cut the shape of the flat pieces with no problem and the drilled holes are easy too. What I'm not sure about is how to get that long slot between the two plates and make it rounded at the black screw's end. I need concentric circles at that end.

I've thought of using a washer or spacer of some kind in the middle, making the whole process easier with some super glue or a little welding. Can 6061 be welded easily? I'm not a welder and have no welding tool but I have a friend who does welding on some of the oil/gas well stuff around here.

The big 3/8" hole at the end needs to have a slot that's about 1/16" wide. I figure a saw of some kind will work here. I have a scroll saw. That could work but I'll have to remove the blade for each piece I cut.

Lastly, (I hope) there's the tapped brass piece that goes into the 1/4" holes. What's the easiest way to convert a 1/4" rod into a tapped 1/4" tube like that? AND it needs to have a 1/8" hole drilled through the middle for a pullrod. You can barely see the brass piece's hole in the top picture.

I'd appreciate any help/tips that could be offered on this one. I'm pretty much a novice at all this milling stuff but I'm a pretty intelligent guy. I can figure it out with a little help.

[neilw20]

Do you have a lathe?
Finish the big hole.
Mount on a mandrel and turn with a parting tool.
Intermittent cut will make it interesting.
Leave the whole thing slightly oversize, then mount on mandrel on mill to finish it. Make the holes last, so that intermittent cuts are less of a problem.
A good insert type parting tool will work well with proper insert designed for aluminum.

[DroopyPawn]

I have no lathe. Well, I have a woodworking lathe but it wouldn't work for this. Any other ideas?

[Larry83301]

You did not give any dimensions for the part, so I’m not sure if this would work. We made a part similar to this in two setups on a CNC mill. First setup, capture the whole part in a vice, on edge, and cut the slot. Second setup, lay part down in vice with the end to be rounded sticking out, cut that first, then finish the holes. We put a spacer in the slot to support the upper leg for drilling the holes.
On a manual mill it could be made almost the same way, except mount the vice on a rotary table with the center of the round end centered on the table.
If the spacer needs to be round, the rotary table setup could be your last setup, using a slitting saw to finish the round spacer.

[DroopyPawn]

The part is 2" x 5/8" x 3/8" thick. The big hole is 3/8" and the small ones are 1/4".
gs

[DroopyPawn]

I guess I could use a 3/16" side mill if I could find one. The limit on my Taig is a 1/2" endmill holder. And that may be pushing it. Any ideas where to get the side mill? About a 1.5" diameter is all I would need. I could program it this way if I can find the cutter.

[Larry83301]

You could get a cutter here> http://www1.mscdirect.com/CGI/NNPDFF?PMPAGE=497
and a holder here> http://www1.mscdirect.com/CGI/NNPDFF?PMPAGE=481
Just remember that cutter dia is NOT how deep it can cut. You need a cutter at least 4" to clear the legs on your part, depending on the size of the arbor nut.
How many of these are you going to make? This may be a deciding factor as to making them yourself or having someone that has the tools already make them.

[DroopyPawn]

I'm in it now so I'll be making them myself. Just need to figure out exactly how I want to do it. It seems there's at least as many ways to mill a part as there are to skin a cat, not that I'd want to.

[blades]

Does the functionality of the part demand that there be a radius around the center bore in the end of the slot? To machine it exactly as pictured is not practical.

_____________
_____________) (please forgive my ASCII-CAD)
^^ slot ^^

There's a few different ways you could achieve the radius per the original part, but they are either somewhat unsafe, or not condusive to any kind of production.

*IF* you could live with the slot as I've got it shown, here's how I'd process this part:

Machine outer profile (thickness, width, length, and large radius)

Drill & ream bore
Drill & ream small holes
Machine slot with part up on edge, leaving a small amount (.005-.008) for a finish pass on each side.

It would be extremely unadvisable as well as dangerous to attempt using any type of large diameter horizontal mill arbor-type cutter on this project! It's an accident waiting to happen, because this part is not nearly large enough to safely hold it in place while using such a cutter. On small parts, you really want to use smaller diameter, higher rpm end mills as opposed to large, low rpm cutters. The smaller end mill will exert much less cutting pressure on the part. A large cutter at a slow rpm will gladly rip this part out of any vise or fixture you have it in, unless you get carried away with special custom made machining fixtures to hold it.