What to do about leaf springs.
I'm making a couple of 11x14 hinged, spring back contact print frames. The wood and glass is no problem. I know there are different ways of closing the back, but I'm pretty fond of those leaf springs. Spring steel is available at different places, but I want to do this for free with stuff I might find or have. I'm not even sure that those springs are really "spring steel". Not that familiar with metals.
Have you found a convenient way to solve this problem?
Re: What to do about leaf springs.
Well, I've never tried to solve this problem, conveniently or not, but one source of spring steel would be a defunct wind-up clock. The mainspring is, like, real springy. I'd be careful taking it apart though, unless the mainspring has already broken. They store a lot of mechanical energy.
I don't know the right way to cut, drill, or otherwise machine spring steel, if there are any. I suspect that if you get the metal too hot, it stops being springy, which kind of defeats the purpose of the exercise.
You need advice from a machinist, and I am not one. But the machinist might tell you that you would be better off to just buy a contact printing
frame and to spend your time making negatives to put into it.
Re: What to do about leaf springs.
How about using an old, large metal coffee can and a pair of tin snips/ aviation sheetmetal shears?
If cut longitudinally it would be pre-bent and springy.
Beware of sharp edges.
Re: What to do about leaf springs.
The tines of a steel yard rake are pretty springy steel and may already be about the right width. I usually see at least one sad old rake when I go to goodwill.
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Re: What to do about leaf springs.
Blue-tempered spring steel from ebay is what you want and it's not incredibly expensive. It comes in rolls. I have two 11x14 commercially-made frames and they both use .050 inch. One uses 1 inch wide strips, the other 3/4 inch. If you intend to drill it (I'd find another way) you'll have to soften where the drill makes the hole, but very locally or drill with a carbide tipped bit. I'd make friends with a local machine shop: they probably have something you could use lying around and could easily cut it to dimension for you.
Re: What to do about leaf springs.
I think I remember seeing some print frames in the past that used wood slats for springs. I think you would want a hardwood, and it would need to be thick enough to give real resistance.
Re: What to do about leaf springs.
you could try to steam some hardwood slats into a slight curve and use those instead.
Re: What to do about leaf springs.
If you have an anvil,or piece other place on which to use a small sledge, a 3 pounder will do, a blacksmith taught me too many years ago to hammer repeatedly along the "spring" and it will become springy.
Re: What to do about leaf springs.
If the metal has a high enough carbon content you can shape it, drill it then heat it to the point a magnet will not stick to it then quench it in oil. This sets the shape and should be pretty springy.
Re: What to do about leaf springs.
Quote:
Originally Posted by
mdarnton
I think I remember seeing some print frames in the past that used wood slats for springs. I think you would want a hardwood, and it would need to be thick enough to give real resistance.
Yep! A rotating slat that is tapered and a long slot of uniform width. Rotating the slat introduces more length and thickness, which cinches the back tight. It holds by friction. Low tech and pretty EZPZ.
Doremus