How to make a moveable arm for goggles

[Mad Bess Flint]

Hello! I am new here and I have a bit of a quandary for a pair of brazing goggles I am attempting to modify. I would really like to attach a hammer from an old clock movement in a way to allow it to stay up and click down (so I can attach a crosshair or other such lens to it..) Here are some pictures to help explain:

The two parts:


The arm up, where I would like for it to naturally stay:


The arm down, where it should click into place (gravity is a major help in this position, all I need is a stop.)


Ideally I would love for it to make a ratcheting or clicking noise when changing positions, but I can't even figure out how to get it to stay upright without interfering with the "swing down" mechanism. I also don't have a lot of interior room to work with on the goggle eyecover so I have hit a major stumbling block on figuring it out. All of my soultions keep getting more and more convoluted... which I suppose isn't a bad thing, but I am certain there is a simple answer to the problem, I just can't grasp it.

[passbyguy]

I think the swivel arm from a broken pair of eyeglasses could. I've used it before, it locks in well for both positions, as long as you get one of those internal spring loaded ones, only hard part i see would be mounting it.

[Narsil]

I would think that a small spring would be the simplest solution. Just arrange it so that it goes slightly over-centre in the down position ie the point where the spring is attached to the goggles is slightly below the pivot point of the arm and to the rear of it. with stops for the arm at both ends of its travel. That geometry should make it stay firmly in place in both positions.

[Dr cornelius quack]

How about getting hold of one of those cheap ratchet spanner sets that come with half a dozen hex screwdriver bits.
Throw the drivers away, ('cos they're always rubbish anyway) and use the ratchet to mount the arm. They normally have a lever to reverse the direction of drive so's you can go down or up and will give a nice clicking sound in the process.

Like this,

[Captain MacMorrigan]

I will be watching this thread with interest, as I too am interested in how to accomplish this (besides the rather unsatisfying putting-a-screw-in-as-an-actual-stop solution).