Help On How To Set Up And Make This Item.

That's not exact but close enough for our purposes.
The pic that I included was just a quick CAD draw and not the exact dimensions either.
As was mentioned, the sides can be perpendicular to the stubs and may well be in the actual part.
 
I guess I missed the part about the tapered threads. They don't seem to show in the drawing. The only way I know to do that is with a taper attachment, so that may be your next project. Sometimes you have to build the tool to build the part.

Since that has to be built in one piece, then the only way to get the 2* dihedral I can think of is to extend the arm center lines out to the opposite end and put the center at the intersection. That may mean a little extra material at the end that you will cut off in the final piece. I think you would have to do this in a CNC lathe also, unless you can find someone with a multi-axis horizontal machining center with live tooling. An angle plate, with a 2* taper built in and the center block bolted to it, attached to a face plate might do it, but it would have to be built pretty stout.

I'm pretty sure this whole job can be done on a manual lathe, but some practice pieces would be in order. Maybe a chunk of free machining plastic to start, like Delran or something, just to refine the technique. I assume the final part will be 4350 or similar alloy.
 
Randy,
That would require flipping the part and you know how that can be problematic and now with a 2º in the mix presents more problems. I'm a master at complicating even simple things at times so it could be that is what I am doing with your idea.

Ken
 
But anything that can be reasonably made with a taper attachment, can also be made between centers with the tailstock offset, including threading.
 
Randy,
That would require flipping the part and you know how that can be problematic and now with a 2º in the mix presents more problems. I'm a master at complicating even simple things at times so it could be that is what I am doing with your idea.

Ken

Ken, flipping the part should not be a problem when turning between centers using a lathe dog. This is done often when identical precise diameters are required on both ends of a part (such as turning for a bearing fit). It's especially common on old lathes like mine where the ways are very worn near the headstock and best accuracy is obtained by turning near the tailstock.

Try a test piece, I think you'll not have any difficulty.
 
Jim,
Dang me, the threads are not tapered and in thinking back I've confused even myself with the term "Tapered" and then related that on to others, sorry every one :(
I've done so much thinking on this I may need a break :D

The shaft is stepped but straight as is the threading and has the 2º dihedral as you mentioned.

Can you elaborate on this a little more
"then the only way to get the 2* dihedral I can think of is to extend the arm center lines out to the opposite end and put the center at the intersection."

The material will be E-4340 Mod Vacuum melt, very tough even in the normalized state but some of the stoutest aerospace material available once heat treated.
 
As said, if the sides of the rectangle are at a right angle with the "spindles" it will be possible to make with a lathe, even easier if there is a shoulder on the spindles that clears the 2º faces.

Building a work holding device will be far more difficult then the actual machining, this will require a milling machine to build the fixture. Interesting job to say the least but doable, a lot of interrupted cut turning knocking the corners off of the out of square rectangle.
Good Luck
4pwapl.jpg
 
Ken, flipping the part should not be a problem when turning between centers using a lathe dog. This is done often when identical precise diameters are required on both ends of a part (such as turning for a bearing fit). It's especially common on old lathes like mine where the ways are very worn near the headstock and best accuracy is obtained by turning near the tailstock.

Try a test piece, I think you'll not have any difficulty.

You can't turn this part between centers as they are not on center as there is 4º included between the features being turned as far as I can tell from the limited part description. The turning is easy, the work holding is difficult.
 
Short of a highend cnc. It will eather be made in 3 pieces and welder by a certified welder or Machined streight and bent to the 2 deg.
 
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