SDD - not what you think:)

[tatsumi]

Hello,

Been working on a new shot saver device and one that will tame the shot variation. in a few posts i've mentioned useing some air tube in the hammer spring with good results, my thought is to tampen the spring and so far its been working great on the AS2250 with power spring but it had little effect in the 2240 with stock spring and no guide.
So i figured i'ed combine the two and grab a little more power at the same time.

So heres what i came up with;





The black o-ring steadys the device in the rear end cap and acts as a break, the little air tube is fitted in the smaller section and the hammer spring is fitted over this. this is where the spring dampening is done and the guide allows for a very smooth cocking action. at the back there is section where the oring is fitted and this acts as a preload. The back has been drilled out as i found that the full mass created variation i did not want so i think i've got it right now.

Result is a very quiet, consistant and slightly increased power. When i've done more testing on both guns i'll stick some results up with all the dimentions so if people want to make one they can.

Cheers,
Ian

[arkmaker †]

Ian,
Your the man after my own heart! Very good innovation!!! Looking forward to some results.
RIch

[quickster47 †]

So this goes in the hammer spring and acts as a guide and a device that dampens the spring. Is that correct?

Carl

[tatsumi]

Cheers rich, I thought you might like that

It does carl, plus preload. The preload is flexible so in mine its 5mm but you could go higher. Also if you fit it to the hammer side you get extra mass!

[arkmaker †]

Cheers rich, I thought you might like that

It does carl, plus preload. The preload is flexible so in mine its 5mm but you could go higher. Also if you fit it to the hammer side you get extra mass!

Still this could work with a Power Adjuster as well. right? Just cut the pre-load down to say 1mm and use the PA screw. Or am I missing something here. And yes, I like it a lot! Been beating my head against the wall with the HDD and trying to quiet everything down, so this fit perfectly with my goals!!
Thanks again for sharing this.
Rich

[T191032]

"Been beating my head against the wall . . . "

Stop doing that.  Then the headache will never go away and you'll use it as the excuse for never getting a good score on the Monthly Targets!   


"So this goes in the hammer spring and acts as a guide and a device that dampens the spring. Is that correct?"

"Still this could work with a Power Adjuster as well. right? Just cut the pre-load down to say 1mm and use the PA screw. Or am I missing something here. And yes, I like it a lot!"

Innovation at work.  Sounds like it could work with a PA.


"When i've done more testing on both guns i'll stick some results up with all the dimentions so if people want to make one they can."

Or find someone who can? 

[tatsumi]

Its designed to seat in the end cap so providing the PA has the hole still then yes. Improving on that it would make more sence to incorparate the guide into the PA so the little bit that goes back and forth has the guide?

I have only a dremol and drill to work with so thats a little out of my reach but the idea would work i suspect.

[tatsumi]

Few more pics showing the spring fitted and possition in end cap

[NorthStaR]

Tatsumi, that's quality! I still haven't tried the tube thing yet but I see your delving ever deeper into it with results.
It's come a long way from squashing a pipe in the spring! I feel a dremel session coming my way...   

[tatsumi]

Thanks northstar
Will post dimentions up this weekend, go get the dremel

[quickster47 †]

Beginning to understand your SDD more and more and you know, that is such a great idea.  Hope you don't mind if I make one or two in the next few weeks.  Really want to see how it does in my guns.

Carl

[tatsumi]

No Not at all Carl, i'm just like you, no intention to make money just improve on our hobbly and get some ideas out. Just been doing some testing so when am done i'l; post the dimentions i have.
Currently working with brass bar.

[mike hunt]

Hi Tatsumi, this is seriously interesting, keep us posted

[tatsumi]

Got some data recorded after much messing and pellets.

15 shots without anything in the spring, 15 with the air tube at 6mm(very important) long, SDD in the back and SDD in the front which originaly caused me some issues but i drilled the back out as you will see in the photo to lighten it, results are pritty good for a non HPA gun. see what you think





Rich- I knocked up a simple spacer for the back to simulate a power adjuster as far as the compression goes, wound cock on mine so pondering on that one. think incorparate the guide and rubber tube some how?

Any way the last graph with the SDD in the hammer(front) seems to be the best, not kicking as much out at times compared to other results but i was after a good consistant shot with power increase a plus. also i did not have to wait per shot with the SDD in, just enugh time to write the result down from the combro and reload.

When i get chance i will test this on the XT but its such a pain having to take the air tube off every time to get to the hammer spring so bare with me on that one. A 2250B would be lovely to have around at the moment.

[tatsumi]

Reading back through it seems to me that they always have the potential to be stable but the relationship between the spring vibration and sloppyness(made that spelling up ) during the fireing cycle create's a problem for the valve to fill correctly, or to the max. Fix that and its looking good.