Airsporter/Mercury spring clamp

[Benelli B76]

After years of working on these, now at 70 have not got the physical strength to hold the weird back end of these straight when fitting a strong spring. Today started making a custom socket for the action to fit in my sash clamp, should have done it years ago. I am making mine out of plywood, and thought for a laugh would ask guys on here what they had made to do this job.

[Shed tuner]

4 layers of plywood, as it makes the inletting easier, profiled to fit. left in two halves, with a couple of bolts, one passing through the large hole in the underlever mount, the other daigonally opposite

Ends up like half a brick, with a nice flat back to fit into the spring compressor. Made it around 1989, still works

[Benelli B76]

4 layers of plywood, as it makes the inletting easier, profiled to fit. left in two halves, with a couple of bolts, one passing through the large hole in the underlever mount, the other daigonally opposite

Ends up like half a brick, with a nice flat back to fit into the spring compressor. Made it around 1989, still works

Jon, amazing, mine will be identical. Somehow I used to be able to line up the threads squarely without any help from special tools. Got a mint Mercury in yesterday, been in the same family since new but the piston was completely seized. After repair tried to fit the spring it came with and found it very strong (or me velly weak !).

Baz

[TonyL]

"Back in the day" I used to have the muzzle on ground (padded, obviously) and handle the back block with a big, thick leather glove.

An idea which makes sense is to clamp the flat sides of the block in a padded vice and, wearing a thick jumper and coat or jacket, to press against the muzzle.

Of course, so much depends on the spring and preload and the idea of the spring compressor adaptor makes a lot of sense.

[Benelli B76]

"Back in the day" I used to have the muzzle on ground (padded, obviously) and handle the back block with a big, thick leather glove.

An idea which makes sense is to clamp the flat sides of the block in a padded vice and, wearing a thick jumper and coat or jacket, to press against the muzzle.

Of course, so much depends on the spring and preload and the idea of the spring compressor adaptor makes a lot of sense.

Tony, me and the wife were having a laugh about the old days in the 60's when we first got married. There was no limit on airgun power and I was always squashing in the most powerful springs in the rifles with the wifes help and almost killed her a few times when things let loose and springs and bits flew around the kitchen. She was happy when we emigrated to South Africa and I forgot about airguns and only collected full bore pistols.

Baz

[Geezer]

A bloke on e thing bay a while ago had a rather impressive wooden contraption for sale along these lines.

Back in the day, I thought the approved method was to start the block moving with a bleeding great tommy bar, then wrap the block in a towel, wedge it between your feet wearing stout footwear and thick socks, and use brute force to hang onto the action leaping up toward your head when it gave way.

But I guess that was the same "back in the day" when trips in the car meant sliding all over the vinyl seats in the back of my dad's Mk3 Cortina 2000E while he chain-smoked.

Such is progress.

[Airsporterman]

"Back in the day" I used to have the muzzle on ground (padded, obviously) and handle the back block with a big, thick leather glove.

An idea which makes sense is to clamp the flat sides of the block in a padded vice and, wearing a thick jumper and coat or jacket, to press against the muzzle.

Of course, so much depends on the spring and preload and the idea of the spring compressor adaptor makes a lot of sense.

Yup! - the brute force method!
Problem is, I probably don't have the strength I had when I last did this.
The other problem being that the fine pitch of the thread makes it easy to cross thread - if you are not careful enough!
I used to scribe a very small fine line on the interface of the trigger block and the air cylinder tube (usually out of sight below the woodwork so is hidden when the stock is refitted) - so that I didn't have to guess the re-alignment - anyone else done that?
I think I will have to look at making up something on the lines of the op, using plywood, built up is a splendid idea!
(could anyone post up any pictures of a suitable clamp? Mick - you seem pretty good at this type of thing!)

ASM

[slow_runner]

Old or young, weak or strong, a good method on all air guns with screw in blocks is to prefit without the spring.
This will let you know where the relative point of thread engagement is.
It takes only a few seconds but can save some considerable frustration and expletives

[Benelli B76]

Yup! - the brute force method!
Problem is, I probably don't have the strength I had when I last did this.
The other problem being that the fine pitch of the thread makes it easy to cross thread - if you are not careful enough!
I used to scribe a very small fine line on the interface of the trigger block and the air cylinder tube (usually out of sight below the woodwork so is hidden when the stock is refitted) - so that I didn't have to guess the re-alignment - anyone else done that?
I think I will have to look at making up something on the lines of the op, using plywood, built up is a splendid idea!
(could anyone post up any pictures of a suitable clamp? Mick - you seem pretty good at this type of thing!)

ASM

Simple little job,I just cut 5 pieces of plywood, 2 plain squares and 3 with cut out to accept the shape of the trigger unit. The made up block now fits squarely to the sash clamp and the threads match. No struggling to bring the parts together by brute force, just wind up the acme thread on the clamp. Pic of block with square side not fitted and finished Mercury.

Baz

[T 20]

After years of working on these, now at 70 have not got the physical strength to hold the weird back end of these straight when fitting a strong spring. Today started making a custom socket for the action to fit in my sash clamp, should have done it years ago. I am making mine out of plywood, and thought for a laugh would ask guys on here what they had made to do this job.

UKNeil gave me just such a plywood socket when he retired.




All the best Mick

[SRV1]

After years of working on these, now at 70 have not got the physical strength to hold the weird back end of these straight when fitting a strong spring. Today started making a custom socket for the action to fit in my sash clamp, should have done it years ago. I am making mine out of plywood, and thought for a laugh would ask guys on here what they had made to do this job.

Hi Benelli,

If you want some photos of the arrangement I have made, just ask......