Designing a Spring Compressor

[Methuselah]

I would build it for more than 2". It's better to have more than you need than not enough and have to build it again. You never know what guns you may want to use it on in the future.

Yup.  Agreed Bill.  It was designed around that push-pull thing.  2" ram travel + 1/2" more if I turn the screw.  But the fixture end can be slipped - perhaps I'll change the bottom bracket to one tall end and use something like an anchor bolt to add more travel?

Pic below, L goes in hole, threaded end through bottom bracket.  So far only other guns are the two listed --- maybe 2 1/2" will at least handle those if I don't have to set a new spring?

The Hatsan 125 I took down with it has a less than perfectly tight barrel lock pin fit.  Other than that nothing I saw worried me that I can't get her shooting accurately (yet)... .  More on that, but probably in the Turkish gate 

[Teep]

For a heavier spring I would add another block to fit the receiver.

[Oldgringo]

I took ideas from several other creations in an earlier thread:



Except for the $3 worth on bolts, nuts and washers, this was made from scraps laying around my shop.  There is a 4" C-clamp and plenty of length adjustment, bungees for hold down and wood shims for final centering adjustments.  Hope this helps?

[Methuselah]

I took ideas from several other creations in an earlier thread:



Except for the $3 worth on bolts, nuts and washers, this was made from scraps laying around my shop.  There is a 4" C-clamp and plenty of length adjustment, bungees for hold down and wood shims for final centering adjustments.  Hope this helps?

Bungees are a good idea, thanks 

I ended up spending $10 on the push-pull clamp, rest is junk lying around.  I think I like your design better, but I was too lazy to cut up and drill a c-clamp.  In hindsight, should have.

[Methuselah]

Hatsan 125 had about 1/2" to 1" of preload on the ram.

More later, getting stink-eye from daughter to get off puter...

Rest:


Dimensions of the wood base.  I THOUGHT it was a 2 X 8, but it measures out at 9" wide.  A 2 X 10 should be 9 1/2" wide.  Anyway, its left over scrap from when a contractor built our addition.  So; Base:  9" wide, 2 3/4 foot long, customary 1 1/2" thick.  The slot under the fixture end could have been made with a router, but it was done on a mill with several passes using an end mill.

Clamp:  push-pull from Amazon.com, rated 500#.  This one:  Uxcell a11120200ux0396 32mm Plunger Stroke 500-Pound Push Pull Metal Toggle Clamp.  Any will do, this one had a 1.25" stroke plus you can turn the screw to gain a little over 1.5" more travel.  My guy here who does machine work said leave 4 or 5 threads in the clamp for 500# load.

Riser under the clamp:  shaved thinner to set height to match the other bracket height (in a table saw)

Fixture to hold the breach at the forks, measured for .005" over the measurement of the breach block on the Hatsan 125 (30 FPE gun), the other two are slightly smaller but they are 14 FPE so less force to hold.  Room cut out for the cocking arm underneath.  It was chopped up scrap.  For a 14 FPE gun probably could have been just an L bracket.  So,  Fixture:  1/8" steel, custom cut with band saw and finished with a file for .005" side clearance

Hardware:  Feet, scrap brackets with glue on foot pads (only found 3, needed 4).  Bolts: clamp, 1/4-20 with a junk plate under.  Nuts are self-locking nylon inserts and there are lock washers too.  Tightened several times over couple days to account for settling into the wood.  Fixture, 1/2" hex bolt, nc thread, support under is > 1/8" thick steel bracket (band saw took off from larger piece).  Large matching washer under head to give support from lateral loading.

Adapter block.  Have a hobby mill at home (doesn't get used much) and some micro bits from Harbor Freight, slotted it some to try and match up to end of the spring block in the gun.  Miserable failure but hey, it got the job done (No artistic ability).

I reckon all this was mostly self-explanatory from the pictures, but if I did anything terribly wrong this additional info may help someone point out my mistakes?




Greg:  Like the idea of just the dead-end.  Be it barrel end or forks you had it covered.  Simple, eloquent --- oh well, I guess mine works too, until the bracket bends anyway...

[Privateer]

Here's one I threw together to work on an AG in a Motel.
 

[Methuselah]

Here's one I threw together to work on an AG in a Motel.
 

Looks like a Hatsan 95?  Looks safer AND better than mine.

[Privateer]

Yes. That's a Mod 95. I like the scissor jacks. I find the small ones all over the place!
It's rated to 1500+ pounds!

[Tater]

Yes. That's a Mod 95. I like the scissor jacks. I find the small ones all over the place!
It's rated to 1500+ pounds!

Where do you just "find them"? Do you mean free or at a garage sale or something?

[Privateer]

Found this one here at the job site. Found 2 others near job sites usually in trash piles or near junk cars.
1st one I ever used was the jack in my Dodge Dakota. I don't use that one anymore.

[T-Higgs]

The sicissor jack thing is awesome. You could get one for a song at a salvage yard.

BUT!! Your aviatar is KILLING my ADD. Must.....try.......to.........focus.......

[Methuselah]

The sicissor jack thing is awesome. You could get one for a song at a salvage yard.

BUT!! Your aviatar is KILLING my ADD. Must.....try.......to.........focus.......

Yeah, usually hold a hand over the ones that move - very annoying, but we still love you Jeff

[Privateer]

OK. I changed the thingy back to my old one.
 
I do prefer the scissor jacks as they are able to lift a car.
I'd not trust a C-Clamp to even try doing that.
Granted an AG should never be that much pressure but they are free or easy to find/buy cheap.
And you have a lot more range with one so it's a multi purpose tool.
They make a good front rest for bench shooting also!

[avator]

Seen some good ones here. I think there is a section on them in the GTA library