Spring compression

[truck]

How much must a spring compressor move to decompress the spring?

[gamo2hammerli]

Is this to remove a main spring?  If it is, the spring compressor just need to move about 1/8th inch or less...just enough so you can tap out the retaining pin.  Then slowly let off on the spring compressor until the spring extend out, and have no more tension.  Work slowly and observe that nothing goes out of line...or the spring might suddenly shoot out.

[Bryan Heimann]

To decompress, up to 3 inches or maybe even a little more.  But some guns operate on zero preload, some of the nicer ones.  Generally, more powerful airguns have more preload.

[truck]

Preload is what I should have asked about. So about 3 inches but maybe up to 4 inches. During the winter I want to check the piston seal and whatever else there is that could be damaged by dry firing. I didn't catch the warning about not shooting cleaning pellets till after I did it 4-5 times. I'm looking into using a c-clamp or similar as a spring compressor and the the length of unsupported spring has me concerned. Things can go sideways pretty quick if the spring gets away you.

[Horatio]

Preload is what I should have asked about. So about 3 inches but maybe up to 4 inches. During the winter I want to check the piston seal and whatever else there is that could be damaged by dry firing. I didn't catch the warning about not shooting cleaning pellets till after I did it 4-5 times. I'm looking into using a c-clamp or similar as a spring compressor and the the length of unsupported spring has me concerned. Things can go sideways pretty quick if the spring gets away you.

I have used furniture clamps. Don't recommend doing it that way again.

My next way of doing this might be this.
See if 1" scope rings will go around 1" hardwood rod from HD.
buy cheap big C-clamp from HD or harbor freight.
cut one end off c-clamp.
bolt the 2 together.

Just an idea.

[truck]

Preload is what I should have asked about. So about 3 inches but maybe up to 4 inches. During the winter I want to check the piston seal and whatever else there is that could be damaged by dry firing. I didn't catch the warning about not shooting cleaning pellets till after I did it 4-5 times. I'm looking into using a c-clamp or similar as a spring compressor and the the length of unsupported spring has me concerned. Things can go sideways pretty quick if the spring gets away you.

I have used furniture clamps. Don't recommend doing it that way again.

My next way of doing this might be this.
See if 1" scope rings will go around 1" hardwood rod from HD.
buy cheap big C-clamp from HD or harbor freight.
cut one end off c-clamp.
bolt the 2 together.

Just an idea.

Could you make a sketch of that and post it? I can't picture what you're describing.

[gamo2hammerli]

I use a 36" C clamp, one end on the muzzle and the other end on a stack of 2 coins/washers on the metal plug that holds the spring in.  As I mentioned, compress slowly and observe...if you see either end slide or move back off and re-align the clamp.  I've done over two dozen spring changes this way and have no safety issue.  Of course a non sliding/rigid DIY spring compressor would be a lot safer and gives you peace of mind.

[Bryan Heimann]

I just use a regular bar clamp, super simple and easy, not to mention inexpensive.  I think mine is a irwin quick grip, works by squeezing the handle to compress it.  Just get the longest one they have.  Remove the barrel from the comp tube, saves you some length and saves the rear sight from potential accidents.  Plus the safety variable of the joint out of the equation.

Half a dozen dry fires on a cleaning pellet, the gun might be o.k.  Give it a chance on the range before you tear it open.

I built a nice spring compressor awhile back, spent a lot of money building it and eventually sold it.  Wish i knew then what i know now.

[Roadworthy]

Three to four inches is adequate for most airguns.  A five or six inch clamp gives you some flexibility, especially if you set up for multiple airguns.  Most bar clamps do not have a long enough jack screw for anything but gas strut type springs.  Unless you're just curious about what's going on in your gun and have no other reason to open it, it's probably fine.  I never remove the barrel of my break barrels unless necessary.  Obviously I don't remove the barrel from a fixed barrel.  My compressor is long enough to deal with either.

[Horatio]

Preload is what I should have asked about. So about 3 inches but maybe up to 4 inches. During the winter I want to check the piston seal and whatever else there is that could be damaged by dry firing. I didn't catch the warning about not shooting cleaning pellets till after I did it 4-5 times. I'm looking into using a c-clamp or similar as a spring compressor and the the length of unsupported spring has me concerned. Things can go sideways pretty quick if the spring gets away you.

I have used furniture clamps. Don't recommend doing it that way again.

My next way of doing this might be this.
See if 1" scope rings will go around 1" hardwood rod from HD.
buy cheap big C-clamp from HD or harbor freight.
cut one end off c-clamp.
bolt the 2 together.

Just an idea.

Could you make a sketch of that and post it? I can't picture what you're describing.

Haven’t made a sketch yet.

Imagine a wooden bar in the scope rings where a scope would be, with maybe 6” of said wooden rod behind action of gun.

Now imagine half of a Cclamp just stuck to the side of the wooden rod.

Depending on ring height the c clamp may need a riser on the wood rod made out of thin angle iron. Just some ideas.

[truck]

OK. I see what you mean now. Do you think the dovetail will handle the force if you get some twisting action?

[Roadworthy]

Pyramyd or Air Venturi (parent company) was selling such a device for about $100.  Theirs would work on either dovetail or Weaver rail.
One member here suggested using PVC pipe (3/4" perhaps) as the material clamped in the scope rings.  He made a screw with all thread and nuts and washers.
If your safety lever comes out the rear use care not to apply pressure to the safety lever.  You may need some kind of adapter.  So far my Dianas are the only guns with a rear safety.

[Yogi]

There are tons and I mean tons of u-tube videos about how to make a spring compressor.
Google is your friend.

-Y

[truck]

I was looking at the videos on UTube and got lots of information about spring compressors so I'm good in that department now.
Thanks for the information you guys provided.

[nced]

Preload is what I should have asked about. So about 3 inches but maybe up to 4 inches. During the winter I want to check the piston seal and whatever else there is that could be damaged by dry firing. I didn't catch the warning about not shooting cleaning pellets till after I did it 4-5 times. I'm looking into using a c-clamp or similar as a spring compressor and the the length of unsupported spring has me concerned. Things can go sideways pretty quick if the spring gets away you.

I use a padded Groz sash clamp for my spring compressor. They are heavy steel construction with a rather long screw to accommodate spring preload...........

https://www.woodcraft.com/products/groz-48-t-bar-clamp?via=573621f469702d06760016cd%2C576328a869702d20ec000b2f
https://www.ebay.com/itm/48-T-Bar-Clamp-1-7-8-Deep-GROZ-39101-/282619900125

[truck]

That is a nice solid looking clamp.👍

[Novagun]

Nice looking bar clamp.  We call them sash cramps.  They work very well as a spring compresser and you can use them for wood working projects.
Never had a airgun mishap with one.

[OleTomCat]

Nominal coil spring preload is 3~6" depending on the gun, it will be longer on a new spring until it is set unless you buy a preset spring...

I built my own spring compressor but I take a lot of guns apart...

[Steelontarget]

I got the Air Venturi spring compressor.  It's worth every penny and I'm glad I got it.

https://www.pyramydair.com/product/air-venturi-rail-lock-spring-compressor?a=7764