Adjustable spring mod

[Syn]

I have a spare JG ver 3 mechbox which I got for a song ($10 lol) and I was thinking of making the spring tension adjustable, not buy too much probably 1/2" or 1".

I think beyond that distance the piston may not fully stroke. Purpose is for FPS adjustable within reason. Say 340-400, without having to disassemble mechbox. Some places have 350 max others are more generous with FPS max.

I was thinking of ways to do it.

I have 3 ideas so far, each has pros and cons like making the box weak, easy to adjust, keep from loosening spring tension, etc.

1) Drill 4 small holes behind the spring guide through the mechbox and using 4 pins (2-4mm diameter) of the same length and welded onto a washer. when installed the pins push on another washer that is on the spring guide and pushes the spring forward a certain distance creating more spring tension. Simple to mod, how will I hold plate with pins in? hmmm.

2) Figuring out how something something like this animation works and trying it. Looks cool, might be had to duplicte. requires IE: http://www.ryobi-group.co.jp/en/proj...ser_fla01.html

3) Something similar to this:

I think this is unlikely solution although looks cool will be the least likely to work because I would need to cut into the side of the box to turn the nut, never mind having to thread the soft brass sping guide. Brass thread would likely shear off lol.

What do you guys think? Comments, suggestions, flaming, etc welcome.




EDIT: I saw this box. I might even hit my spare box with the dremel if it does not weaken it too much. Not the front part of the box, just a small opeing in the rear part.
Anyhow still debating options in my head.



this looks interesting too http://airsoftcanada.com/showthread.php?t=54981

[Kos-Mos]

That is a version 2 mechbox.

It might work, and the most feasable way would be the 3rd one.

But It won't varry much, since you are just changing preload...

[DarkAngel]

hmm, give carl a PM (Madmax) maybe he can try something out
the idea is good i think

tho im curious how an armalite stock would screw onto it (cause it might cause the adjustment screw to turn too)

[Syn]

KOS-MOS:
Preload only you say? I better take a prudent step and just try to put a washer over onto the spring guide enough to compress the spring another about 1/2" and see what happens during shooting , before I start modding parts.

DArkAngel: Why ask others to do something I could do myself and have fun learning by modding. I love modding things.

[DarkAngel]

sounds good tell us how it turns out