How would you choose to efficiently make 48 of these?

[dbb-the-bruce]

Of course efficiency depends on what matters to you most. I'm thinking time and minimize setup.

The major diameter is 1" and the length of the standoff is .58ish

I have a lathe (South Bend 9) and a drill mill (27" X). I'm thinking that I would start with 1" round stock, cut two lengths (about 15" long). Drill 12 holes in each for the saddles and spaced so I could then feed the stock through my lathe with a collet and turn the tee cylinder shape, parting off and alternating each.

However, there are a bunch of problems with that approach and it's not going to work!
#1 I can run 1" stock through my spindle
#2 It's going to fall apart when try to turn the small diameter and the tee is facing the wrong way.

So, second idea: Drill a bunch of holes in the round stock for the saddles, bandsaw apart so I end up with 24 pieces of stock with a saddle at each end.
Use my 3 jaw on the lathe - part is not that critical so 3 jaw centering error won't matter much.
This will work, but the fat base is only .31" thick so it will be fussy.

So maybe make some sort of custom fixture to go in a 3 or 4 jaw?

I look forward to suggestions!

Dave

 

[Ulma Doctor]

If you are so inclined, you could turn the diameters and part off to length
Make a simple fixture to hold in the QCTP holder that retains the part
Hold a ball endmill in the 3 jaw chuck and relieve the part as necessary by transverse operation of the cross slide

 

[Superburban]

Do you have an endmill that can cut that radius in the end?

I would rough cut the pieces on the bandsaw. then go through all of them, and face one end, and maybe even drill the hole. Then go through each, and turn down the small diameter. Then you need a way to quickly and accurately clamp each down, and use the mill to cut the end radius. Thats where the right size endmill would be great.

 

[SLK001]

I have a lathe (South Bend 9) ...

#1 I can run 1" stock through my spindle

Well, first your #1 is false. You CAN'T run 1" stock thru your spindle.

Do you have a steady rest so that you can face one end and center drill it? If so, mount the piece between centers, or the chuck and the TS center and make as many as you can from one long piece. Forty-eight pieces will probably have to be done in two or more setups. Once the general form is complete, use your band saw to separate the pieces, then mount them individually and face the back and drill the hole. Then on to your mill to create the radius.

If you don't have any way to center drill your stock, you're going to have to probably do them individually. Band saw them to length, face one side, drill the hole, flip the piece and cut it to size, then on to the mill.

 

[RJSakowski]

Of course efficiency depends on what matters to you most. I'm thinking time and minimize setup.

The major diameter is 1" and the length of the standoff is .58ish

I have a lathe (South Bend 9) and a drill mill (27" X). I'm thinking that I would start with 1" round stock, cut two lengths (about 15" long). Drill 12 holes in each for the saddles and spaced so I could then feed the stock through my lathe with a collet and turn the tee cylinder shape, parting off and alternating each.

However, there are a bunch of problems with that approach and it's not going to work!
#1 I can run 1" stock through my spindle
#2 It's going to fall apart when try to turn the small diameter and the tee is facing the wrong way.

So, second idea: Drill a bunch of holes in the round stock for the saddles, bandsaw apart so I end up with 24 pieces of stock with a saddle at each end.
Use my 3 jaw on the lathe - part is not that critical so 3 jaw centering error won't matter much.
This will work, but the fat base is only .31" thick so it will be fussy.

So maybe make some sort of custom fixture to go in a 3 or 4 jaw?

I look forward to suggestions!

DaveView attachment 338566View attachment 338567

I would use a 1" 5C collet in the collet chuck on my lathe for work holding. I would turn my reduced diameter slightly over length and drill the center hole. Then I would part of the piece and face the large diameter, if necessary. Next, I would mount the 5C collet with a stop in a collet block and cut the saddle in the mill with an appropriate end mill or with a boring bar. In absence of a collet chuck for the lathe, a four jaw chuck or a three jaw chuck and oversized stock could be used. I would still invest in the 5C collet and the collet block for cutting the saddle.

Be aware that using a 5C collet can cause differences in dimensions due to slight differences in diameters or tightening. Joe Pieczynski did and excellent video a few months back on these errors.

 

[Jimsehr]

What material? What radius? What size bore and is it thru Hole? Do you have a saw?

Jim

 

[NC Rick]

Danger, don't take advice from me because I don't have a lot of experience. I would band saw blanks that were a bit too long. 5c collet with a stop and make the Minor diameter to length and dimension. After those were done, I would set up the collet in a square block in the mill for the partial hole. Then back to the lathe to face the excess off the rear of the part. With no collet stuff I likely would make a square of aluminum that stopped in the 4 jaw Chuck with a fitting hole and a saw slot. The fixture should transfer to the mill too.

 

[ArmyDoc]

No dimensions on drawing, so I'm kind of estimating. Is the diameter of the circle/hole going through the piece about 3/4 inch? If so, you'd have about 1/8 on either side when drilled through the major diameter. So if you cut off a piece of stock long enough for two holes, with a part on each side of each hole, you'd be making 4 pieces out of each length.

- First get your length, and major diameter and drill center hole through entire piece.
- Then drill the two holes in the bar. Drill your two holes in the stock far enough apart for two bases, two stand-offs plus the parting tool width and maybe a little bit of fudge factor.
- Next, cut the two ends off in saw, through center of the holes (ends will be a bit long I'm guessing) Save them for later.
- Turn down minor diameter of one end of center section
- Part off through in the middle -> first completed piece.
- Flip other end around and turn down minor diameter of other end -> second completed piece.
- put first end piece in and turn down minor diameter -> third completed piece
- Put second end piece in and turn down minor diameter - > fourth completed piece.

Do this 12 times.

Alternatively, don't center drill it. Turn to major diameter between centers. Drill as many appropriately spaced holes as will fit on the bar you can turn. Cut off and turn pieces as above, center drill after turning minor diameters.

 

[Asm109]

How concentric must the two diameters be? tolerances on diameters?
does the face on the 1 in diameter have to really square to the diameters?
Those tolerances will drive the order of operations to me.

 

[mickri]

The first thing that I would do is draw a scale drawing. Based on your 3d views of your part it looks like you have the skill to do that. Based on the dimensions that you have listed you would need a bar 43 inches long plus the width of the saw cuts plus the width of the face offs. Say .1 x 47 = 4.7" for the saw cuts and the face offs. You will need at least 48" of material. Three 16" long bars should be enough to make 48 pieces.

My order of operations would be:

1. If you need to, turn the bars between centers on your lathe to 1" OD.
2. Drill the holes for the saddles on the mill. Depending on the finish you need in the saddles you may need to use an end mill or a reamer to finish the holes.
3. Turn down the tee sections holding the bar between centers on your lathe.
4. Cut the pieces off on the band saw. Parting will use up too much material and you may not be able to part off the saddles.
5. Finish off the saw cuts and drill the center hole on your lathe..

That's how I would do it.