How would you choose to efficiently make 48 of these?

Thanks everyone for the ideas - and making me think about it more thoroughly.

I did say the major/largest diameter is 1", along with the total length of the standoff - thought that would be enough for these purposes.

Tolerances are not very tight - all that really matters is the standoff height and that the flat and saddle are square to the axis. I bolt slides loosely through the center hole.

Material is phenolic or something like that. Not high temp or any other requirements just needs to be strong "enough" ( FYI - standoffs support the large rubber ball S tracks in a bowling ball lifter! )

This discussion has made me realize that there really isn't a way to save time by pre-drilling the saddles. The diameter of the saddle hole is .875 - there would be very little left holding a 1" rod together after drilling.

I don't have an end mill that big (or a drill for that matter!). I don't think I would have much use for something that size on my benchtop drill mill - just not rigid enough! However, will probably be fine with a slightly softer material. Any of my attempts to plough a 1/2" mill into the side of a chunk of metal have been less than satisfactory so far, other than pretty small depths of cut.

So it seams like the best approach (for me) will be to by some appropriate 1" rod stock, bandsaw off 48 short lengths, then use my 3 jaw, face an end, use a chuck stop insert thing when I flip them around, turn the tee / smaller diameters and then go to the mill to do the saddles.

Any thoughts on a material to use? I did a quick look on MSC for phenolic and found "Easy-to-machine Garolite rods" stuff is pretty pricey.

There is probably a cheaper plastic that would work (does need to hold up in outdoors/sunlight). I don't really know my materials that well.

-Dave
 
I just went to shop and cut a piece of plastic to show how I would do it.
I have a KDK qctp holder that will take a 5c collet. If I did not have one that takes a collet I would mount a Alum block on cross slide and drill a bore with a slip fit for part size then saw a slit so that I could clamp part by a Cross hole and a bolt. Then turn block 90 degrees and you are ready to go.
1601403545215.jpeg
 
Depending on what all tooling you have available.....
Start on the late with the longest bar it can handle.
Set up a follow rest if you have one, second choice is a steady rest but you will have to move it repeatedly.
Face the bar, machine the Major dia and the small dia, then drill the center hole.
Part to length. If the parted face is not clean enough for the final use then leave enough stock to face it off.
If that facing is necessary then put it back in the 3 jaw gripping the small dia and using the shoulder to keep it square against the chuck jaws and face to final length.
Now head for the mill.
Set it up with a V block and 2 parallels with the small end facing up. Make a cut across with a ball end mill of the correct size.
If no ball end available, then set it up horizontal with a locating stop and plunge down with the correct size flat bottom end mill.

A dimension drawing would help refine the best order of operations.
 
dbb-the-bruce said:
This discussion has made me realize that there really isn't a way to save time by pre-drilling the saddles. The diameter of the saddle hole is .875 - there would be very little left holding a 1" rod together after drilling.
Click to expand...

Thinking outside the box, one way you could pre-drill the saddles would be to do the center bore first, drill the saddles, then pass a bolt up the center. That might give you the rigidity needed to turn the narrow diameters...
 
OK now I see some more dimensions and info.
The original 3D drawing is not even close to scale. that changes how I would do things.
If the big end is 1.000 inch what is the Dia of the small end and the thru hole?
You say .875 drill thru, does that mean the saddle radius is .4375?
The length is .58ish. Is that to the top of the saddle hole or to the very bottom edges?

Phenolic is hard and abrasive, and does not like impact loads at all. Does this actually contact the bowling balls?
 
dbb-the-bruce said:
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
Click to expand...
3/4 schu40 PVC pipe
dbb-the-bruce said:
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
Click to expand...
3/4 sch 40 pvc pipe has 1.05 od and .804 Id . Pretty cheap and easy to get.
I see you have the So Bend 9 with the 1 inch collet . So you could bore a soft emergency collet to 1.05 . Then saw or cut off part about an inch long ,then hold on that extra inch and radius The end. Then recollet and turn the 2 od sizes and bore and cut off.
Bet you can get emergency collet for 10 or 15 bucks. And you can reuse it for other jobs.

Shars has collet for $7.45 + $6.50 shipping

Jim
 
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SLK001 said:
The spindle bore on a SB 9" is 49/64", or 0.765".
Click to expand...
If you go to sb catalog #97 and go to page 36 you will see a 1 inch capacity belt driven lathe that is exactly the same as the other 9 lathes except it has a 1 3/8 hole through spindle that takes 1 inch collets.
Jim
 
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