Tuning Why aren't springers externally preload adustable?

[Treefrog]

This has been bouncing around in my head for a while.

The shocks on motorcycles are easily (and externally) adjusted for pre-load, so why not springer airguns? Wouldn't it simplify things if you could tune the gun to the pellet instead of buying/trying pellets to work well with the gun?

I can think of at least two ways that it could be accomplished, and I'm not that smart. I did search the web and haven't found anthing substantial on the subject. If the Crosman Quest 1000(!) that I had to tame had come with a simple adjustment, I'd probably shoot it more... I'd also be finding out what tension shot which pellet the best.

Thoughts? Am I behind the curve here?

Cheers,

J~

 

[Sqwirl57]

I've actually considered this. A turn in dial of sorts inside but partially petruding the main tube at the trigger assembly would work. You'd need a tool to turn it but it would work. It wouldn't even necessarily have to stick past the tube. As long as there was a slot to reach in to stick a tool to get leverage would work

 

[Struckat]

I would buy one now. 15fpe at full power and crank it down to 7 or so would be great for me.

 

[Sqwirl57]

I would buy one now. 15fpe at full power and crank it down to 7 or so would be great for me.

That seems like a stretch. At best I think you would be able to get a couple ftlbs but I think the big benefit would be tweaking the shot cycle and timing to a specific pellet at a rough power level

 

[Treefrog]

I've actually considered this. A turn in dial of sorts inside but partially petruding the main tube at the trigger assembly would work. You'd need a tool to turn it but it would work. It wouldn't even necessarily have to stick past the tube. As long as there was a slot to reach in to stick a tool to get leverage would work

Interesting. Like you adjust brake-shoes so that they just touch the drum when you reline the rear brakes.

I was thinking of a bolt through the center of the rear cap as a means of adjustment.

Cheers,

J~

 

[Sqwirl57]

Interesting. Like you adjust brake-shoes so that they just touch the drum when you reline the rear brakes.

I was thinking of a bolt through the center of the rear cap as a means of adjustment.

Cheers,

J~

Exactly like that was my thought. Your method would work but on many guns the trigger components would be in the way. My thought is to basically make it so its more or less an adjustable base to the rear guide

 

[John "spysir" Blount]

Because springers have springs? (just messing with you).

As far as adjustable gas rams no reason at all except perhaps they fear overfills. Theoben made adjustable gas rams for years.

John

 

[Septicdeath]

Simple answer. Because it makes you buy more airguns and pellets.

 

[boscoebrea]

Cost and the possibility of user's mistakes, The Fact is a car can have different powerplants that are not adjustable, you can have 4 or 6 cylinders.

Adjustable power is up to the individual,he or she can change it by tune kits.
You have a choice, Like a R-7 or R-9 or what have you. Cost and too many people would find a way to screw it up, truth hurts,so does too much tampering by the general public. A great idea though.

 

[beerthief]

" use it wisely " is a phrase the public at large does not follow .

 

[Northwoods22]

Used to be that feature was an option on R/C vehicle shocks. Now, even many of the entry level vehicles in many scales come with threaded shock bodies and collars to quickly and precisely adjust spring pre-load. It's rapidly becoming a standard, rather than an upgrade.

It's a cool idea for adaptation to a springer. Externally adjustable, maybe by a single step with a wrench, no tear down or changing tune kits. I'd say development/manufacturing cost and liability concerns would be the big things a manufacturer would have to weigh.

If someone like Weihrauch made a springer with that feature, it was proven to work reasonably well, and wasn't terribly expensive, I'd probably try one.

 

[beerthief]

Used to be that feature was an option on R/C vehicle shocks. Now, even many of the entry level vehicles in many scales come with threaded shock bodies and collars to quickly and precisely adjust spring pre-load. It's rapidly becoming a standard, rather than an upgrade.

It's a cool idea for adaptation to a springer. Externally adjustable, maybe by a single step with a wrench, no tear down or changing tune kits. I'd say development/manufacturing cost and liability concerns would be the big things a manufacturer would have to weigh.

If someone like Weihrauch made a springer with that feature, it was proven to work reasonably well, and wasn't terribly expensive, I'd probably try one.

connect post 10 with the thought of liability and the public

 

[Treefrog]

I can see how people would either abuse it or break something out of ignorance. A guy at the range managed to cram an 8mm Mauser cartridge into a 7mm Mauser once. That bolt never opened again, but it held together.

If I get some time over at Dad's machine shop, I'll see what can be done with the Quest. It would be interesting to cut the spring a little and then see what happens with the velocity as the compression is gradually raised. The gun was heavily greased with lithium bearing grease to smooth the shot cycle and lost ten percent of its velocity from that.

Cheers,

J~

 

[MrP]

" use it wisely " is a phrase the public at large does not follow .

“Remember to like, comment, and subscribe! Today i am going to try to hit 86 fpe 1400 fps with the new adjustable Gamo spring piston by overloading the main spring (with the help of this 18” long barrel extension) and adding a healthy dollop of my personal “diesel-magic” formula”.

 

[boscoebrea]

Go do it and get back to us,it would be interesting to see what you can achieve.if not it is but a pipe dream.
I know this, many guns are tuned for a specific pellet; Think this, for every tune there might be a best pellet,so now you have at the most 4 different tunes for 4 different pellets that took you umpteen hours and pellets to figure out.That ain't the way of Capitalism,I want 4 different guns that shoot four different ways for 16 different pellets That have 4 different mounts with four different scopes...yea,that's the ticket

 

[HPP-Mechanic]

Interesting. Like you adjust brake-shoes so that they just touch the drum when you reline the rear brakes.

I was thinking of a bolt through the center of the rear cap as a means of adjustment.

Cheers,

J~

Brake shoes & drums?!?!?!? Damn, I thought I was the last person on earth that remembered those...

 

[KWK]

Turn the star nut with a spoon or back up and stab the brakes to adjust. Don't forget your baking plate grease so they don't squeak.................
A lot of cars use them for parking brake inside the disc.

 

[Sawney Bean]

I don't see where this is something that can be practically accomplished. Just think about where a spring is situated on a springer and how you'd have to adjust it externally. The spring is generally riding partially inside of the piston and in front of the trigger group.

I'm sure someone could come up with a way of making it adjustable, but I seriously doubt that it could be done in a practical manner that would be worth the extra cost and complexity.

 

[MartyMcFly]

I don't see where this is something that can be practically accomplished. Just think about where a spring is situated on a springer and how you'd have to adjust it externally. The spring is generally riding partially inside of the piston and in front of the trigger group.

I'm sure someone could come up with a way of making it adjustable, but I seriously doubt that it could be done in a practical manner that would be worth the extra cost and complexity.

It can certainly be accomplished, rather easily too! Back in 2020, in the depths of Covid induced lockdowns, I came up with an externally adjustable springer design. Actually, three designs came to mind, but here is the simplest form that would require minimum alterations to an existing gun. Since then, I've worked out much more elegant designs, but they will require some dimensional changes in the trigger group.

First, as many of us know changing the pre-load can significantly alter the power output and shooting dynamics of a springer. The typical springer has a metal spring guide, with a small outer lip at the base, upon which resides a metal washer. Adding or subtracting washers at the base changes the preload on the spring that sits on the washers. The preload obviously depends on the stack height of the washers. So how can you change this externally without physically adding or subtracting washers?

The solution I came up with is to have the outer walls on the base of the spring guide (let's say 1/10th of the way) to be threaded. Next, instead of having a simple washer you replace it with a threaded ring (call it a nut, if its simpler to imagine), which moves up and down the spring guides threads. Spinning the nut on the threaded portion will compress or decompress the spring's preload. But how do you make the ring adjustments from the outside of the gun?

The simple, but crude solution is to have a cut out on the side of the tube (ahead of the trigger), that is just wide enough to allow you to spin the nut. In my design the nut is really a ring with knurling on the outer circumference in order to allow your thumb to spin the exposed portion of the ring. One caveat is that the spring guide has to be made stationary in order for the nut/ring to move up and down the threading. Furthermore, it takes a lot of torque to move the ring under preload - but this can be addressed using gears in more elegant design.

-Marty

 

[thumper]

Most all springers are setup to run at or near coil bind anyway. So there isn't a lot of wiggle room to alter power significantly enough to make it worth doing IMO.

And how are you going to overcome the bounce in the cycle once it's turned down? A bouncy gun is the most aggravating and hold sensitive thing you'd ever shoot.

If it existed, I'd run from it personally.