Hi all,
I've certainly browsed here in the past and I am hoping that someone can o ffer me some relevant advice, and that this group is not too corrupted by a ll the political messages I just saw.
I would like to make a spring, actually, about 200 springs. They need to be extension springs, about 1" long and 0.25" diameter, but tapered so tha t they can be fit into an Approximately 0.23" diameter hole and will go onl y half way through. The upper part of the spring will stick out of the hol e and will serve as an electrical contact for a wire just as in the electro nics kits of yore.
I need these to be inexpensive (Less than about $0.20 per spring), becaus e I need a lot of them. If someone knows of a source of custom springs tha t can make these, please let me know, and the rest of the discussion below is moot.
Because they need to be inexpensive, I am thinking the way to go is to bu y uncut spring stock from McMaster-Carr (e.g. this stuff:
But, can I taper them myself? My thought is to make a jig in a drill press . A 1" length of spring would be dropped into a tapered hole. I would the n press a pin down the center of the spring to expand the top half into the tapered hole. I would then push a semi-circular slide into place to retai n the spring and slide it off the pin as I pull the pin back up. The enlar ged portion of the spring would be at most 0.5" long, though probably close r to 0.375" long.
This scheme seems to me like it might work, but I have a few questions.
1) Has anyone done something like this before?2) I presume the taper has to be a little bigger than the desired ID of th e spring, as it will spring back a little bit. How much bigger?
3) Does anyone have suggestions on a nice way to cut the spring to length so I don't have sharp edges that cut fingers?4) What spring material is most amenable to post-forming?
Thanks, and I look forward to the group's helpful and imaginative response s.
Dan