Measuring recoil spring rate

Anybody know of a simple way to tell the rate on all these recoil springs
rolling around my work bench ?

Put something running lengthwise through the spring. A dowel with a loop will work. Compress the spring against something by pulling the loop with a fishing scale. Measure the weight once you get to 2" or so. There is a guy that sells a tool for this on Ebay, but I made one pretty easily that works satisfactorily.

I picked up a Weston 20 Pound Spring and Hook Scale on amazon for $18. Then get a 5/16" x 8" wooden dowel, 2 fender washers, and a 6d finish nail.

Drill a hole in one end so a 6d finish nail will fit with a press fit. You want it to stay put. Drill a hole in the other end for the fish scale hook to fit through. Slip one fender washer onto the dowel so it rests next to the nail. Then from the face of fender washer mark a line at 1 7/8". Put spring onto dowel then place the second fender washer on the dowel. Now put dowel onto fish hook and and compress spring until until the washer reaches the dowel.

The scale I mentioned has an indicator so you will be able to tell what the spring weight it.

Thanks, I'll give it a try.

Post a picture!!

Here is a simple Spring tester design that was suggested to me by RT of Oregon I made one and it works fine. It will give you the basic idea.

Scott
Vermont

Scott Carroll wrote:Here is a simple Spring tester design that was suggested to me by RT of Oregon I made one and it works fine. It will give you the basic idea.

Scott
Vermont

You clamp he square tube in a vice. Also with a different size rod and a second hole set in the tube you can load 22 springs.

Way cool. I'm going to fab up one that does recoil and mainsprings....it should make it easier to tune marvel conversions.

so it is pretty easy to load the spring and measure it with a scale.the question is at what compressed length do you measure the weight of the spring. I am asking about recoil springs here. but since someone brought up recoil springs what is the compressed height of them>

For most springs (not just gun springs) spring rates are pretty constant until you get close to fully compressed and fully relaxed. I'll get back to you after I build my rig to confirm that is still true for these recoil springs.

the proper compressed length for a recoil spring is 1 7/8" to measure its rated weight.

You can take a known good or new spring and use it to calibrate your set up.

Toz35m wrote:the proper compressed length for a recoil spring is 1 7/8" to measure its rated weight.

You can take a known good or new spring and use it to calibrate your set up.

I thought it was 1 5/8". Anyway, my experience with a "fish scale" was not good- too inaccurate. I used a combo of dumbbell plates and bullets to compress the spring. Then I weighed the weights on a good scale.

Thanks gents

Fred T

Probably a bit more complicated than you were looking for, but I figured I'd put it out there.
http://www.realguns.com/Commentary/comar16.htm
Bill

I use one made by a bullseye shooter in Colorado.

It works great.

http://www.ebay.com/itm/45-cal-Spring-Tester-/140916066564?pt=LH_DefaultDomain_0&hash=item20cf408904

Art wrote:I use one made by a bullseye shooter in Colorado.

It works great.

http://www.ebay.com/itm/45-cal-Spring-Tester-/140916066564?pt=LH_DefaultDomain_0&hash=item20cf408904

Thanks for the link - I just ordered one

Art wrote:I use one made by a bullseye shooter in Colorado.

It works great.

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http://www.ebay.com/itm/45-cal-Spring-Tester-/140916066564?pt=LH_DefaultDomain_0&hash=item20cf408904[/quote[/url]]

What do you use for a scale with that tester.

djm,

I use this spring scale:

http://www.amazon.com/Weston-Pound-Spring-Hook-Scale/dp/B001IHF6GC/ref=sr_1_2?ie=UTF8&qid=1361547337&sr=8-2&keywords=weston+spring+scale

I got the scale from Steve Bathje - the guy that makes and sells the spring tester - you might contact him to see if he still has them.

Art

Another simple method is to take a can and make a hole in the bottom, a little larger than the shaft of a phillips screwdriver. Place the spring on the screwdriver and then the screwdriver through the hole in the bottom of the can. Place the can on a scale and compress the spring using the screwdriver. Read the scale when the proper length is reached.