Need nomenclature name

rwdenney said:
Wristwatches use something similar for securing straps to watch cases and they are called "spring bars". But they will be at most 2mm in diameter and 24mm long.

Rick "need more info about application" Denney
Click to expand...
Didn’t think of that. That’s why I ask you knowledgeable folk. Spring bar. Now I’ll just have to figure out how they’re made.
 
It wouldn't be too difficult to make something out of nesting brass tubing, perhaps useful for prototyping something. I have used the stuff to make a rotary seal for a decorative spinning water sprinkler.
 
Maplehead said:
Didn’t think of that. That’s why I ask you knowledgeable folk. Spring bar. Now I’ll just have to figure out how they’re made.
Click to expand...
I can probably guess at that pretty well. They comprise an outer tube that is cut from drawn tubing. In that, they install two bar ends that have a tiny flange on the end. The flanged ends compress a coiled spring between the two bars. Then, they use a press to form over the ends of the outer tube to 1.) contain the flanged ends so the bars are retained, and 2.) to reduce the wiggling of the bars where their diameters are a bit smaller.

The pins in these are hardened and tempered and made from strong material. The tubes, not so much--they may be stainless steel or even brass. The usual strategy for removing them when corrosion has locked them up is to cut them across the middle (where the spring is and not where the pins are) using diagonal cutters.

I buy them by the bag and they are cheap, so they have to be easy to make. I bet the pins are made in a stamping machine and then they are heat-treated for hardening. (The more I think about it, the more I doubt the pins are hardened, particularly for the cheapie Asian-made versions bought by the bag, but I'm sure they are using stronger steels than the usual stainless they use for the outer tube.)

If they need to be big enough to allow it, I'd make it as above but instead of forming over the center tube I would machine it with a small-diameter inner flange at one end, and then make the tube in two pieces that are threaded together.

Rick "trying to guess where such a thing would be used on a guitar :cool:" Denney
 
McMaster-Carr carries "long-nose spring plungers". The body is threaded, and can be had in plain or with a thread locker strip. But the travel is somewhat restricted -- a 6-32 body maxes out at .063". But maybe that's enough for your mystery project :).
 
I watched a YT vid of a guy taking apart his telescoping gauge and yeah, it’s pretty basic the mechanics. I’ll make one tomorrow for my needs. Thanks all.
 
If you invent it, you get to name it. Just choose wisely, it might be the difference between famous and infamous.
 
You must log in or register to reply here.
Back
Top