How to make this part

[martik777]

I need ~100 pcs

Tolerances are +/- .003 except where noted, material is 3/8" 416

1. Machine .248 end and .370 step
2. Cut off to overall length +.005
3. flip over and machine .173 end

Trim all pieces to exact length with a spindle stop

Total time ~7 mins?

 

[Karl_T]

A CNC lathe with bar feed could pop these out well under 2 min each

 

[BROCKWOOD]

Looks like about $60 + shipping for material. I'm a hobbyist, so really could not devote time if a quick turn around is required. Neither do I think I could do the 1st 30 or so with an average of 7 minutes per part. I'd say, for what machines I have, I'd be doing good to ave over 100 pieces about 15 minutes or less ea. I don't see a good compromise between what I should charge & what you would expect to pay.

Of course Karl_T is right about CNC being quickest & most accurate. I know not what you would expect to pay though.

 

[Asm109]

run out requirements one diameter to the other?

 

[pontiac428]

Cheeeit, a 120-year-old B&S screw machine could knock those out in about two or three seconds from bar stock feed, each!

Turn, turn, chamfer, chamfer, part... next!

 

[ddickey]

Buy 100 1.250" sticks. You could use the same collet size for the whole operation. I think 7 min is very doable.

 

[davidpbest]

I was curious to see with Xometry would quote on this job. Have a look - 100 pieces in 416 ±0.001" tolerance.

 

[davidpbest]

Oh, and that's from a USA source. In a day or so I'll get an actual "firm quote link" after somebody reviews the 3D model, and it will have the ability to source it from China. Past experience suggests this same 100 pieces from Chinese CNC source would be $800-900 (delivered) with a 4-5 week leadtime. I have stopped manually making parts that require 25+ quantity, and started outsourcing it to Xometry (usually USA sourced to support das homeland).

 

[mmcmdl]

Hardinge or any other second op lathe would make this an easy job .

 

[Parlo]

If you have a manual lathe with DRO then I would use a Seco MDT tool or equivalent and turn the whole thing in one hit with the same tool. Cut the bar into 20" lengths that will fit inside the lathe headstock withot protruding making 19 pieces per length. You should be able to hit under 4 mins per piece. Knock the sharp corners off before parting.

I think 2 or 3 seconds on a 120 year old screw machine is ridiculous.

Edit: Link to tool - https://www.secotools.com/article/676?language=en