SPRING COMPRESSOR - Questions

[Tarheel]

Well, it's finally happened. I am working on building a spring compressor !

When the spring is uncompressed in break-barrels, how much space do I need to allow for it to expand, when designing my compressor to allow for this?

I am going to be using a small scissor-jack on my compressor. It's maximum extension length is 10". Is that sufficient length ?

Thanks, in advance !

Dave

[nc shooter]

You'll need up to 4" of travel when building a spring compressor. When I took the spring out of my remington vantage, it only came out an inch and then it was loose.

[JimL911]

Different guns need more than others. 10" travel is plenty.

[Tarheel]

Great . . .

Thanks for the help !

One more question, if you don't mind . . .

When mounting the action to decompress or compress the spring, should :

(a) The muzzle be allowed to contact anything solid or be used for leverage or applying pressure ? ( I say "no" to this one )

(b) The forward end of the Breech Block ( under the barrel ) be used for leverage or to apply pressure ?

(c) The forward end of the Piston Tube, with support on both sides, be used for leverage or to apply pressure ?

Thanks !

Dave

[JimL911]

Go with "B". I pass my barrels through a hole so the block not the barrel takes the pressure.

[blind dog]

I let the muzzle do the thrust load bearing, for better or worse, but it protrudes into a hole in a block of soft wood that is packed with replaceable foam rubber padding. No problems so far, and most compressors I've seen do something similar.

Having said all that, I prefer to use somethign other than the muzzle, but it would have been difficult to do the way mine is designed to be very adjustable for different guns. The barrel rests in a vee-block with the muzzle in the padded 2-1/4" diameter dead-ended hole (big enough for the sights to fit into), and both the screw clamp block and the spring chamber hold down vee-block are set-up to rest on a number of different bolt-down positions and held with wingnuts and washers.

[Tarheel]

Go with "B". I pass my barrels through a hole so the block not the barrel takes the pressure.

That makes sense to me . . .

I may look at using a combination of "b" and "c" .

Thanks !

Dave

[Tarheel]

I let the muzzle do the thrust load bearing, for better or worse, but it protrudes into a hole in a block of soft wood that is packed with replaceable foam rubber padding. No problems so far, and most compressors I've seen do something similar.

Having said all that, I prefer to use something other than the muzzle, but it would have been difficult to do the way mine is designed to be very adjustable for different guns. The barrel rests in a vee-block with the muzzle in the padded 2-1/4" diameter dead-ended hole (big enough for the sights to fit into), and both the screw clamp block and the spring chamber hold down vee-block are set-up to rest on a number of different bolt-down positions and held with wingnuts and washers.

I am going to use adjustable blocks to brace and position the action.

Thanks for the tips !

Dave

[Onebaddj]

I use option a. The biggest thing is to make it adjustable. I can use mine on just the tube or a long barreled tube like a 350. I just unbolt my c clamp and move it back and forth. Also i put a get latch across where my gun sits just incase something gos wrong the gun cant come out of the compressor. Ill try to find pics on here that i have of it.

[Tarheel]

I use option a. The biggest thing is to make it adjustable. I can use mine on just the tube or a long barreled tube like a 350. I just unbolt my c clamp and move it back and forth. Also i put a get latch across where my gun sits just incase something gos wrong the gun cant come out of the compressor. Ill try to find pics on here that i have of it.

Thanks, I'd like to see those pics.

Dave

[Onebaddj]

http://www.gatewaytoairguns.org/GTA/index.php/topic,2701.msg21617.html#msg21617

The link above is to a strand about spring compressors. Should help you out with some ideas.

[nc shooter]

Here's a pic or 2 of my super simple spring compressor I built in about 30 mins. might help you, might not.

[Tarheel]

Here's a pic or 2 of my super simple spring compressor I built in about 30 mins. might help you, might not.

Ivan,

I have never seen a compressor designed like yours.

Thanks for sharing those pics !

Dave

[VAFarmer]

Unless it's a Gamo type gun, where it is really hard to break the pivot assembly loose, I separate the barrel from the action.   Just to be safe.  Mr Murphy has been hard on me in the past...   I dont own a sidelever or underlever, so no pressed barrels.

In all seriousness, I think it actually makes it easier to work on. 
More manageable length.
Dont have to worry about inadvertantly banging the crown against something.
You can get into the barrel easier, for serious cleaning.   If you needed to lap, or remove the seals and use solvent, just so much easier to handle with the barrel loose.  Lots easier to inspect the bore by looking down, instead of picking up the gun and trying to manuver it around.
Easier to polish/clean up the lead-in on the bore.
You can fiddle with the detent and thrust washers, and improve if necessary.
Heck, I'll be honest, but WON'T advocate......If I remove the barrel from a gun, usually rated up to 1000 fps, I just build a block to push against the ears of the tube, with a block between the ears, and push down on the gun to disassemble.   IF all the assembly can be accomplished with one hand 

I always remove the barrel.  Lots of potential for improvement in the pivot area, and easier to work on with it off. 

Just my 2.

God bless,

Farmer

[dwood5]

Unless it's a Gamo type gun, where it is really hard to break the pivot assembly loose,

Hi VAF,

I've encountered this with my Gamo 440. After getting it apart, I couldn't see any reason why it was so tight.

After breaking several screwdrivers, including my impact one, I finally gave up, put the receiver in my mill and machined it out. After the 'body' of the bolt was out, I was able to remove the small threaded piece with my fingers. It wasn't tight at all.

Just wondering if you've figured it out?

Regards,

DON

[VAFarmer]

I used a vise,  and a phillips of the correct-size (milwaukee brand bit, not the cheap harbor freight Im normally prone to use).
Put the Gamo in the vise, perpendicular.   Locked the vise. Removed the barrel breech seal.   Heated the nut side with a propane torch for a few min on a fine point flame, to try to avoid heating the ears/flanges of the tube. Once it got "spit hot" where spit would sizzle on it,  put the driver in, cinched a pipe wrench around the driver handle, put an extenstion of pipe on the pipe wrench, and took a framing hammer to the end of the driver.  Then started applying force to the screw, while giving the end of the driver a medium to hard tap.  Figured something was gonna break loose, and fortunately for me it was the screw.

Best I remember, Gamo uses some funky tapered screw.   Honestly think what helped the most was the expansion of the metal.   Whenever you work on old balers or tractor rim nuts or something big (OR Gamo pivot screws   ) remember this.......Heat it, beat it, and leverage.  Your impact driver gives the percussion, but heating tends to break loose rusted--stuck--and epoxied.   Works well when pressing also.... and the leverage is a big friend too.  The torque I was applying was probably 2.5-3 foot from the inner radius of the driver.  Lots more force can be applied to that fulcrum point from a farther radius, and often can be applied at little more evenly.  The percussion is where things can just break, cause your tolerances between your tools and the object can be altered easily.

When I reassembled, I got it tight, and used blue loc-tite, but didn't hit it with a torque wrench or anything.  I wouldn't have know what setting to go to anyway.
I don't like working on Gamos, cause if you mess them up, you're done.  Unless you know somebody, or have a parts gun, internals are hard to get.

Hope some of this makes sense.

God bless,

Farmer

[blind dog]

Sounds like Gamo is using red locktite.

[dwood5]

Hi again VAF,

And to the poster above, I don't think they are using Locktite at all. I also heated mine with a hot air gun. Got it waaay hotter than I could touch without burning myself.

Like in my previous post, I put mine in my milling machine, dialed in the threaded side, and drilled an undersized hole down about a half-inch.

Then put a punch in that hole and gave it a solid hit with a hammer. The body of the bolt came out with ease. The bolt body broke off from the threaded portion where the threads are undercut and the shoulder of the body begins.

Then what amazed me was I took an EZ-out "in my fingers", stuck it in the drilled hole of the threaded portion, and backed it out without any effort at all. That is what leads me to believe there was no Locktite.

Since the body of the bolt came out so easily, and the threaded portion [I believe 6mm threads] unscrewed so easily, I still don't know why I couldn't unscrew the thing originally considering the massive amount of force I used.

Oh well. Now I'm in the process of trying to obtain parts from Gamo. You can follow my quest on the Gamo GTA, subject "Gamo Customer Service".

DON