HELP NEED ADVICE.

[JSRLDesign]

I need to make 1000 to 4000 lock nut parts that look like [see attachment]. The nut needs to be Al. The key elements are the hole locations and the thickness of the part [0.25"]. I assumed that the part could be made using 1/2" x 1/4" bar stock, tapping the 10-24NC hole and then drilling the 2 #37 holes, cutting the part off and then advancing the bar stock forward and repeating the process. I can't find anyone that has a bar feeder for a milling center.

Does anyone have any suggestions on how the part may be made in a different way? I think I could use round stock, machine a flat, tap the 10-24NC treaded hole [axial direction], drill the 2 #37 holes [perpendicular to bar axis], then part the piece off. Advance the round stock and repeat the process. Finishing can be done in a vibratory finisher. The part needs to cost < $0.25/ea. i would also like to minimize the tooling cost.

[HuFlungDung]

I would try to avoid handling all those little pieces as much as possible. That means work them in larger sections, then seperate them as the last operation.

I think you'd have to build a 4 sided fixture to be indexed in a 4th axis.

Stock size you'd need would be 1/4 x 3/4 x whatever length, say 7.5".

Initial machining done in a soft jaw vise: gang about 8 pieces (on their edges) in the vise. Machine 1/4" slots, 1/2" deep across all the parts, on 3/4" centers. This leaves you with a bunch of 1/2" wide 'teeth' bound to a backbone that is still 1/4" thick.

Second operation, you machine your rotary fixture so you can clamp these premachined parts on there, making the faces of what will become the nuts accessible, and the edges are also accessible to drill and tap all the holes as required. You would need to prepare the fixture with clearance holes for the tap to run into, since that is the orientation of that hole.

Third operation: clamp these parts in the vise again, slotted side down, and machine the backbone away, releasing all the parts. You will need to be clever about clamping or the parts will come loose and jam up the tool as they are cut free. I would use a piece of UHMW about 1/8" thick (but whose thickness is accurately parallel) on the movable jaw of the vise as a cushion to clamp the bits. UHMW will crush a little and serve as a good stiff spring to keep the pressure on all those little pieces as they are cut free. I'd probably rough cut about .230 off initially and then take the final .02 off in hopes of not disturbing any of the pieces.

BTW, $0.25 is a bit too cheap for that part. You'll be busting your hump to make $40/ hour. The government will be making more profit on sales tax than you do for your effort

[JSRLDesign]

HuFlungDung
Thanks for the input. Your suggestion triggered another thought. How about stacking the 1/4" x 1/2" bar stock pieces one on top of the other so the 1/2" sides are horizontal. clamping the stack, Tapping the stack from the top, then drilling the #37 holes from the side. After removing the drilled and tapped bars cutting them with a laser to the final length dimension [1/2']?????

JSRLDesign

[HuFlungDung]

Maybe if you are the guy running the laser You've always got to worry about locating the part properly when the cutoff occurs, as well as making exact allowance for the kerf width.

Come to think of it, I don't know if the laser guys cut aluminum? I know they don't like to cut brass.