Making a tapered extension spring

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: http://www.mcmast er.com/#9664K47) and cut the pieces into 1" lengths.
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
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On Tue, 12 Jan 2016 10:38:24 -0800, Daniel Koller wrote: ...

...

You could try using a slotted stick (like a lead-former), thin enough to fit down the center of the spring; install a spring, without bothering to taper it, by folding half of the bottom turn across (so the slotted stick can catch it) and rotating the spring into position while pressing it into the hole. (Probably could use an electric screwdriver.) After several turns have rotated into place in the hole, withdraw the slotted stick. The spring expands to fill the hole, holding it in place.
...

...
Dremel?
--
jiw

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At work I've ordered custom and catalog springs from Lee Spring and Century Spring and been happy. URL's are the obvious www.leespring.com and www.century.com. Buy extension springs, cut the loop off the end that will capture the wire or just flex it off to the side so the tool will pass, then make a tool and screw them in as James suggested using the loop on the other, bottom, end. Go with either stainless steel for corrosion protection since they will get lots of rubbing in use.
----- Regards, Carl Ijames
"Daniel Koller" wrote in message
Hi all,
I've certainly browsed here in the past and I am hoping that someone can offer me some relevant advice, and that this group is not too corrupted by all 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 that they can be fit into an Approximately 0.23" diameter hole and will go only half way through. The upper part of the spring will stick out of the hole and will serve as an electrical contact for a wire just as in the electronics kits of yore.
I need these to be inexpensive (Less than about $0.20 per spring), because I need a lot of them. If someone knows of a source of custom springs that 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 buy uncut spring stock from McMaster-Carr (e.g. this stuff: http://www.mcmaster.com/#9664K47) and cut the pieces into 1" lengths.
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 then 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 retain the spring and slide it off the pin as I pull the pin back up. The enlarged portion of the spring would be at most 0.5" long, though probably closer 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 the 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 responses.
Dan
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"Carl Ijames" wrote in message
Hi all,
I've certainly browsed here in the past and I am hoping that someone can offer me some relevant advice, and that this group is not too corrupted by all 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 that they can be fit into an Approximately 0.23" diameter hole and will go only half way through. The upper part of the spring will stick out of the hole and will serve as an electrical contact for a wire just as in the electronics kits of yore.
I need these to be inexpensive (Less than about $0.20 per spring), because I need a lot of them. If someone knows of a source of custom springs that 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 buy uncut spring stock from McMaster-Carr (e.g. this stuff: http://www.mcmaster.com/#9664K47) and cut the pieces into 1" lengths.
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 then 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 retain the spring and slide it off the pin as I pull the pin back up. The enlarged portion of the spring would be at most 0.5" long, though probably closer 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 the 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 responses.
Dan
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    Hmm ... stepped diameter, or tapered?

    How about making them yourself? There used to be a really good web site on how to make springs on a site called "bazillion.com". I can't find it right now, so it may have moved.
    Anyway -- for tapered -- let's assume that you have a lathe (which will make things a lot easier).
    Start by taking some steel and turning a taper to match the desired ID of the spring (a little smaller, really, because of springback).
    Cut a notch in the small end, and put the end of the wire in the slot and start the lathe turning slowly. You will need to make some kind of guide, of course. Wind the wire up the taper a bit past where you need to be.
    As for the ideal wire to make springs -- normally steel music wire sold in rolls from the usual machine shop suppliers like MSC.
    But -- for the kind of contact springs which you are describing, I would suggest phosphor bronze instead. It should be a good contact material.
    Starrett makes a compound leverage end nipper (No. 5, IIRC) which is good for music wire and other spring wires. This is the kind of tool you want to make the cuts of the wire.
    Get good leather gloves to avoid cuts from the spring unwinding when you cut it off.

    Your quantities seem to favor making them yourself. Over 1000 or so it is time to ask a company to make special springs. (This is again assuming that you have a lathe.
    Good Luck,         DoN.
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Hi all,
How does one attach a photograph in Google groups?
I may have found an answer to my question. First of all, both Lee Spring and Century Spring are prohibitively expensive. I just checked their *sto ck* springs and they are ~~$1-~$2 a pop. No way. I'm looking for somethin g in the range of 10-30 cents per spring.
So just for fun I drilled a stepped hole in a block of aluminum and stuck a piece of 0.188" OD spring in the hole, and used a tapered center punch i n my drill press to open the spring up. It immediately collapses. In the larger part of the hole, it can fall out, and in the smaller lower portion of the hole where it's constrained, the coils fold in. No good.
But it happens that if I turn the drill press on, the friction between th e punch and the spring tends to unwind it, and it opens right up to the OD of the punch. I was able to open the spring up to ~0.230 OD at the widest. So, with a properly shaped taper (or perhaps 2 or three to carry out the op eration in steps) I think I can open the spring up to the shape I want.
I have before and after pictures I can post if I can figure out how.
Dan
On Tuesday, January 12, 2016 at 1:38:28 PM UTC-5, Daniel Koller wrote:

offer me some relevant advice, and that this group is not too corrupted by all the political messages I just saw.

to be extension springs, about 1" long and 0.25" diameter, but tapered so t hat they can be fit into an Approximately 0.23" diameter hole and will go o nly half way through. The upper part of the spring will stick out of the h ole and will serve as an electrical contact for a wire just as in the elect ronics kits of yore.

use I need a lot of them. If someone knows of a source of custom springs t hat can make these, please let me know, and the rest of the discussion belo w is moot.

buy uncut spring stock from McMaster-Carr (e.g. this stuff: http://www.mcma ster.com/#9664K47) and cut the pieces into 1" lengths.

ss. A 1" length of spring would be dropped into a tapered hole. I would t hen press a pin down the center of the spring to expand the top half into t he tapered hole. I would then push a semi-circular slide into place to ret ain the spring and slide it off the pin as I pull the pin back up. The enl arged portion of the spring would be at most 0.5" long, though probably clo ser to 0.375" long.

the spring, as it will spring back a little bit. How much bigger?

h so I don't have sharp edges that cut fingers?

ses.

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    First off -- while *you* may be reading and posting in Google groups, what you are really posting in is the Usenet newsgroup rec.crafts.metalworking, which google has imported into their "groups". The rules vary among the *many* servers carrying the newsgroups, and one
non-binary newsgroups.
    Rec.crafts.metalworking is *not* a binary newsgroup, so the proper solution is to find a web hosting service of some form or other, put the images there, and post the URL to view those in the newsgroup posting.

    [ ... ]

    O.K. Solved!

    Please *don't*. Do as I suggested above and put them on some web based service, and post the URL for the images in your article.
    Enjoy,         DoN.
--
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Hi Don,
Ok, understood. Thanks. So the Usenet groups still more or less exist? Haven't they all been susbsumed by Google? I've been using usenet groups for a VERY long time (20+ years!) but didn't think they were still viable a s a source of information. I'm happily proven wrong.
Is there a decent freeware usenet reader that I could use instead of Goog le? How do I get rid of or filter all the annoying political messages at appear (at least within my set up of google) in rec.crafts.metalworking?
I presume that rec.crafts.metalworking is not moderated.
There must be a binary dump I can just link to and throw the pictures in th ere, but for the extra effort required, I'll wait till I have some decent p ictures and not just the two quick ones I took. We'll have a couple days o f digging out of the snow here, so I'll hopefully have some time to play in my shop!
Thanks for the help,
Dan
On Tuesday, January 12, 2016 at 1:38:28 PM UTC-5, Daniel Koller wrote:

offer me some relevant advice, and that this group is not too corrupted by all the political messages I just saw.

to be extension springs, about 1" long and 0.25" diameter, but tapered so t hat they can be fit into an Approximately 0.23" diameter hole and will go o nly half way through. The upper part of the spring will stick out of the h ole and will serve as an electrical contact for a wire just as in the elect ronics kits of yore.

use I need a lot of them. If someone knows of a source of custom springs t hat can make these, please let me know, and the rest of the discussion belo w is moot.

buy uncut spring stock from McMaster-Carr (e.g. this stuff: http://www.mcma ster.com/#9664K47) and cut the pieces into 1" lengths.

ss. A 1" length of spring would be dropped into a tapered hole. I would t hen press a pin down the center of the spring to expand the top half into t he tapered hole. I would then push a semi-circular slide into place to ret ain the spring and slide it off the pin as I pull the pin back up. The enl arged portion of the spring would be at most 0.5" long, though probably clo ser to 0.375" long.

the spring, as it will spring back a little bit. How much bigger?

h so I don't have sharp edges that cut fingers?

ses.

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    It is nice to encounter someone who knows about usenet, and does not think that Google is the be-all and end-all. :-)

    There are a number of servers around. I use www.newsguy.com. You can either use your own newsreader via NNTP, or their PC program DRN (Direct ReadNews). They charge, but not a painful amount. I use slrn as my newsreader on a Sun workstation running Solaris 10. The 's' in its name sands for "scoring", so you can both subdue articles based on poster or "Subject: " header (or other things) or boost them to early in the reading experience, based on similar patterns.
    The www site mentioned above tells you how to subscribe, and offers the (DRN (Direct ReadNews) reader with the subscription. For NNTP, the actual NNTP connection is to "news.newsguy.com" once you have your account.
    One of the rules which helps a lot (but slows down the startup of the newsreader) is to give negative scores to articles with more than one newsgroup in the "Newsgroups: " header. The more newsgroups, the more negative the score, and the more likely it is to be killed totally.
    Also -- strong negative scores for political party names and candidate names help greatly, as well as for certain frequent posters who will quickly become obvious.
    The number of free news servers is slowly decreasing. One of the common ones recently shifted to a paid mode.
    "eternal-september.org" is in general a bad choice, because they have a habit of protecting trolls, so kilfilling sometimes focuses on the news server.

    Depends on your platform. I know mostly ones for unix/linux flavors, and do not use Windows for anything connected to the net. (Nor for much else, given the choice. :-) Others here can suggest Windows based newsreaders.

    A killfile, or the scoring feature in slrn and strn. (Both of the latter are unix/linux flavored programs, while there are some for Windows.) Both of the above may require you to compile from source, though slrn comes pre-compiled on Solairis 10's "Software Companion" CD of freeware. Not sure what you can find for Windows. Perhaps some of them have been ported.

    Back when it was formed, nobody foresaw the need for moderation, and the amount of work needed to reform it as moderated is perhaps beyond reasonable -- aside from finding enough people willing to serve as moderators these days. We've lost a *lot* of good people.

    Not sure whether I will even have power come tomorrow, thanks to that snow. We'll see. :-)
    There are a number of sites which will host photos for free -- often at the cost of some advertising. If *I* need to put up some, I have my own web server, though it is more likely to be an entire project related page rather than a couple of photos.
    There used to be a local site which was called "The Dropbox" which was run by a local metalworking club -- but the name was bought a few years ago, so that is no longer an option -- though whoever bought the name might serve the function.

    You're welcome.
    Good Luck,         DoN.
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