Anyone have a source for replacement springs for Swampy regulator

I tried some websites but I don't know exact specs of it....any help from u college boys!...or girls...engineer types...
Thanks

 

Doesn't sound like that hard a science project, you know the dimensions (or can easily measure them) so really you just need the spring constant. Measure how much it compresses under 50 or 100 lbs (That's what gym weights are for right?) and bam you're done. Im sure you can get a suitable replacement on the internets, try Lee Spring for instance. And post the results!

 

Gym weights?...those things you buy at yard sale... stub your toes on and trip over constantly...crack a walnut or two with and eventually sell at your yard sale?

 

suppose I could use a floor scale and large clamp on a table and compress it.

 

...must have a white lab coat!!

 

I'm on TV? are you filming me again??

Sure the spring constant can change over time depending on how the material that the spring is made from ages and what forces are applied to it. (a bow from young/fresh wood has a different spring constant than the same bow 5 years later if you let it dry out) For metal springs that is of course a much slower process but metals do age and depending on use conditions/maintenance you can change the spring constant. (That is why they tell you not to store springs compressed for long periods of time, well that and the stored energy can be a safety issue.)

When you say lightweight reg are you talking about the old lightweight swampy regs? Those are just regs that were put on a lathe and had a lot of brass removed to save weight (and the associated safety concerns are why they are banned in IRCWCC, to my knowledge no calculations were every done and vetted showing that the amount of material remaining was enough to hold the required pressure with a significant safety margin.) but anyway the spring in those should be the same as the spring in the "heavy" swampy regulators.

If you put the spring on a rigid surface and then use a known weight to compress it and measure the deflection you can determine the spring constant. Not sure how well that would work on a scale but I'm sure if you designed the experiment correctly and the scale surfaces were rigid enough you could probably get pretty close. You could also probably get pretty close if you reverse engineered the regulator, do some free body diagrams, little bit of math, etc....Physics is pretty handy for that sort of thing.

 

reverse engineer... free body diagrams!?....MATH....!!! Me squish spring measure then me squish spring more and measure.

 

Never hurts to learn something new, it is all easily available on these here Internets, you can do it!

 

I'm not sure that you will get the information you need by testing your old spring. Trying to use the measured spring constant of an old spring will get you a new spring that performs exactly the same as your worn out spring. Plus the spring rate should be constant - if it takes 50 lb to deflect the spring the first 1/8", it should take an additional 50 lbs to deflect the next 1/8", or 100 lbs for a 1/4". Your measurement isn't showing a linear trend like it should.
Using the length, spring diameter, wire diameter and number of turns would get you closer to what you need. Unfortunately, the catalogs I looked at don't show the number of turns. Here's one from McMaster Carr that, although a little long, may be close to what you need:
Compression Springs


Choose steel music wire for strength; spring-tempered steel for heat resistance; brass for durability and heat resistance; or phosphor bronze for strength, heat resistance, and corrosion resistance.
For technical drawings and 3-D models, click on a part number.

Zinc-Plated Steel Music Wire—Closed and Ground Flat Ends
Spring
OD Wire
Dia. Compressed
Lg. Max.
Load, lbs. Rate,
lbs./inch Pkg.
Qty. Pkg.
1" Overall Length
0.625" 0.120" 0.78" 114.95 516.70 3 9657K316 $8.38
0.75" 0.135" 0.76" 135.05 564.60 3 9657K318 9.80

 

Part Number​

LC 091GJ 02S​

Outside Diameter​

0.563 in​

Hole Diameter​

0.594 in​

Wire Diameter​

0.091 in​

Load At Solid Length​

68.550 lb​

Free Length​

0.750 in​

Rate​

258.30 lb/in​

Solid Length​

0.483 in​

Rod Diameter​

0.362 in​

Number of Coils​

3.1​

Total Coils​

5.1​

Finish​

PASSIVATE PER ASTM A967​

Material​

SS​

I think I found an exact match at Lee Spring minimum order 10 at 7.61

 

The smaller McMaster spring was
to long will try to modify...
Things got put on hold in middle of jumping thru refinance/ VA hoops ...


Steel Compression Spring

Zinc-Plated Music Wire, 1.00"Long,.625" OD,.120" Wire
9657K316