Mike, how thick is the original spring? What the guys are saying is
you need the same thickness feeler guage. Half as thick is 1/8 as
"stiff", so .005" is 1/8 as strong as .010 - and i suspect your
spring as closer to .020 or 025"
Of course it will distort - that's how it works - by flexing. Unless by
"distort" do you mean "yield", with a permanent distortion. If so, I
don't think so - feeler guages are pretty hard & the video doesn't show
that much deflection in the springs. Try bending a feeler guage by hand
- about the same radius as the Omnigraph spring while running. Does it
yield? If not, keep trying smaller radii until it does yield. I'll bet
that the radius that it does yield at is much smaller than will ever
happen in the Omnigraph. In which case, you're set to go.
Yes, it kinks permanently, I am bad with my terminology!
The problem seems to be that it doesn't bend evenly along it's length in
use, the 3 attaching screws have square plates under the heads to clamp
the spring & weights -they must focus the force and leave a slight
crease in the shim stock after a couple test runs. It almost works but
I'm not happy with the results.
I am trying to keep this original as possible, not just hack it up with
any old spring that will "work".
On Tue, 06 Aug 2013 16:39:54 -0500, "Lloyd E. Sponenburgh"
If he hasn't done that before, trying to get it right with such a thin
piece is not likely to be successful.
Quenching a thin blade evenly isn't usually accomlished by dunking it
in water or oil. You'll preferentially quench one side, resulting in a
weak and, probably, a curved piece. Swishing it around does NOT
accomplish it, if we're talking about something thinner than 0.030" or
I have a nozzle made as a coil of bendable copper tubing, with many
spray holes pointing inward, that screws to my laundry-tub faucet. I
made that after a lot of wrecked pieces.
Not if you PLUNGE it vertically. Besides, he can layer material to
equalize the quenching.
C'mon... this isn't rocket science, it's craftsmanship. Artisans have
been doing it successfully by hand for three centuries.
On Tue, 06 Aug 2013 16:58:50 -0500, "Lloyd E. Sponenburgh"
Good luck. I haven't been successful doing that, except once or twice
by pure luck, and I've heard from experienced heat-treating people,
and knife people, who also say not to do it.
Maybe your eye/hand coordination is a lot better than mine d8-)
This is a very thin blade. They're very hard to quench right. My
experience is mostly with hacksaw bladers, carbon steel, which I use
for a lot of things.
The action of a fly-weight governor is controlled by two things. the
weight of the fly-weights and the strength of the springs. Altering
either alters the critical RPM.
So, you can make a couple of new springs and try them. If the speed
falls in the right area you say there is adjustment. If not then make
two more springs, either stronger of weaker as the case may be.
It's not rocket science and you can cut and drill most spring material
with common tools. It is a guess but I'd think that once you obtain
some spring stock, say a spring from a steel tape, and collected the
tools you could probably make 10 or 15 pairs in an hour, or maybe
You aren't listening. The temper / hardness does NOT affect the spring
rate, only how far it will bend without damage. Make it too wide and
grind it narrower to tune it.
If you don't believe us, clamp two long hardened drywall screws
upright in a vise by the tips. Adjust the clamping depth so they both
vibrate at the same pitch when plucked. Then anneal one to red heat
with a torch. The pitch doesn't change, since the mass and Young's
Modulus stay the same.
Push on them with your fingers. Both will deflect identically until
the soft one yields.
I'm listening, just not understanding!
So you are saying I can't change the properties of a spring, that I must
find the same material as the original if I want the new spring to be
the same dimensions as the old one?
Almost correct: You can change the properties by hardening/tempering...
just not the spring force. It remains the same (nearly) for any given
alloy, regardless of the hardness
The primary property you change by altering the hardness is the yield
force, NOT the spring force.
You also can affect (positively) the durability of the spring by
increasing the yield point IF the deflection is such that it comes close
to the yield point when not hardened.
Someone recommended feeler gauges for stock. Also consider the rewind
springs in cheap tape measures (don't use an old, discarded one, as it
might already be severely fatigued).
Lloyd answered that clearly -- the spring rate will be almost exactly
the same, no matter what grade steel you use (except stainless) and no
matter how hard or soft it is.
What varies is the yield point (look it up) and, consequently, the
Maybe we can simplify this for you: How much, in inches or
millimeters, does that spring deflect at the ends, when it's in use?
Be patient; you'll get it. By now you know that you started with some
very common misconceptions. I've even known experienced machinists who
didn't believe it when it was explained to them. So you're not alone.
But we'll enlighten you. d8-)
Ok, given your application, I'd suggest that you take the advice of
another poster and buy some spring stock from Brownell's. The one-off
flat-spring business is something that gunsmiths and their suppliers
are very good at. It probably is the easiest way for you to arrive at
I haven't looked at a Brownell's catalog for close to 20 years, but
for many things, they're the source. They know what they're selling.
You can harden it. Tempering it reduces the hardness.
"Tempering" is the process of taking full-hard metal and reducing the
hardness in order to increase the durability and flexibility.
So... quench-harden it to full-hard, then temper it down.
Heat treatability is dependent on carbon content.
You have a piece you can spark test? Just
barely touch it on a grinding wheel to check the
spark display and find stock to match it...
Then do the quench and temper treatment.
Blue temper should get you close to spring
action. You may have to do several....
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