Wednesday, October 3, 2012

Hinges (Nightmare)

It is hard to get small hinges in the right size or shape. When I started making miniatures I bought a lot of hinges from several sources because then I just could go to my hinges drawer and select the right hinge for the piece I was working on. Reality is another story :-)

Below is a mockup to see how the hinge fit in the current project. To the right is the smallest hinge I had in my stock and I didn't like it. The hinge is too large.

So I had to make my own. First I draw the hinge parts in the right dimensions and then cut the parts from a piece of  0.1mm brass-sheet using my cnc.  That was an expensive experience because I broke a milling-cutter in the first try. But I made a hinge in the right size.

The hinges was then made using the photo etch technique. Here comes the nightmare :-)
The first sheet I etched from the same 0.1mm brass sheet had parts for 96 hinges but after etching and trying to assemble the first hinge I discovered that the brass was too thin. When opening and closing the hinge it just fall apart. Then I tried etching 0.2mm brass using the same layout.
Doubling the thichness to etch also doubles the etching time and that gives problems with socalled underetching and I haven't thougt about that. So back to the drawing board and after a few more trial and errors I managed to make this sheet of hinge parts.

For assembling the hinges I made this needle nose pliers. It is ground from a cheap fleamarket find (don't take the best from the toolbox).


 
5 hinges before next step

To ensure that the pin stays in place I decided to solder the pin in place.
Why not glue? Because glue is hard to control in small spaces and can easily make the hinge unusable.
For soldering I use solderpaste normally used for soldering small electronics. The solderpaste contains flux and pewter and can be applied very acurately in small amounts. I got mine from ebay and despite the small container says something about a shelf life of 6 months and cool storage it works well after about two years in a drawer.

Here is some solderpaste on a bottlecap (diameter 28mm) Half of the paste that the red arrow points to is placed on the hinge.

The hinge is placed on a heat resistent surface.
The hinge is heated a few seconds with a heat blower.
Solderpaste before heating
Solderpaste after heating. The solder flows nicely into the hinge,
After the other end of the pin is cut off  the hinge is ready for use.

Have fun
Niels
 

5 comments:

  1. Wow Niels....thanks for sharing. So when we need those small hinge we can buy them at your place?? Please let me know if you sell them.

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  2. It has been in my mind but I need a better etching system before starting production in larger scale. /Niels

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  3. Niels, I think that Dorien is absolutely right! I'd love to buy some too, they are so perfect! And not all of us are capable of making our own, especially that small!

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  4. Have you tried to back your hinges with a rubber backing it will let the etching work from one side and let you control the process a little better.

    Mario.

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  5. aah, hinges... indeed, construction is tedious and a nightmare :( But I've never seemed to've had trouble with the pin falling out. Cutting 'm short leaves a widening dent, or even filing it down if it is still protruding makes for a small rim, enough to keep it in. Your delicate solution is more elegant though. Very good! The real nightmare here is they tend to fall on the ground, especially when they are done or almost done. And guess what? I think they make a run for it... gone! :(

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