Basic Disco SSG

[robertr]

 First off , thanks to Bob Sterne for this nifty little device.
 I wanted a simple SSG for my brother's new Disco, this is what I came up with and the results after install. First test with it as you see it here, It is set with about 1mm free hammer travel, I more or less made to set it the way you want and leave it. Big improvement after first string I think. My brother is not into tuning at all so I just need to get him 30 good shots. I used JSB Exact Heavies.
 Test is from 2000psi to 1000psi. Some pics.

[BigTinBoat]

Nice job, did you just use the stock spring? Only buying a nut, bolt and o-ring?

[robertr]

Yes , stock spring, piece of rod from an old barbeque grill and a couple of nuts and o-ring from my stash.

[mobilemail]

Cool!  Your airgun kung-fu is strong!

[robertr]

 Yes but soon enough I will land on my  .

[robertr]

 I added another o-ring to the back of the adjuster , I am using the gap on the hammer to adjust my curve just because I have no weaker hammer spring right now and it seems to be working as far as I can tell. The gap is now just under 2mm. Once I get a weaker spring I will test again. I used JSB Exact 8.4's this string , these are the weight of pellets my brother wants to use mostly.
2000psi down to 1000psi. Looks like 30 - 32 good shots.
 Is this good or can I do better?

[MichaelM]

looks like your still a little over hammered for the pressure range.... and starting close to the top of the curve...  and could use a touch less spring or a touch more gap or better yet another 100 psi or so to the fill pressure.... but other then that its a really nice looking string with a lot of good shots!!! if you start out a bit lower you may pick up another half dozen or more shots at the beginning of the string......

personally I wouldnt change anything on the gap or spring preload and add a bit of pressure (up to 2200 psi unless you replace the valve screws)  until you get the first shots in the 890-900 fps range( to match the ending speeds of your current string) then you could stop the shot string around your current sht#36 or 37.... would give you a better extreme spread AND pick up a significant amount of shots to the total string(not to mention ending at a higher pressure means less pumping to refill lol)


 

[robertr]

 Thanks Michael, good to know I am on the right track, I will take your advice and also search for a lighter hammer spring.

[Tater]

Great job on  that Robert, you're brother will be thrilled. Especially if he hand pumps.

[robertr]

Thanks Jerry, no complaints from my brother, he is happy. Hand pumped his SynRod once, knew that would not last long and built the Redneck Compressor. He borrowed me the money to buy my Scorpion SE so I guess I owe him that much.

[shorty]

http://www.gatewaytoairguns.org/GTA/index.php?topic=108168.msg1030023#msg1030023

Looks like you could have done it with a lot less work and nothing sticking out the back of the gun.

[K.O.]

http://www.gatewaytoairguns.org/GTA/index.php?topic=108168.msg1030023#msg1030023

Looks like you could have done it with a lot less work and nothing sticking out the back of the gun.

Shorty there is a difference between pushing a system that you like and coming into a thread that some one has made their choice of system  and built it as a gift... then sounding like richard cranium by putting it down...

geeeeesh...give it a break

[robertr]

 Shorty, it really was not much work at all, just look at it. Besides I enjoy it, and it sticking out the back is no problem. Thanks for your opinion though.

[shorty]

Seriously didn't mean it like that.

Sorry if it came across like that Robert. I was just trying to show how the SSG system worked better the the short stiff spring.

[robertr]

 No problem Shorty, I will be looking for some different springs to try.

[MichaelM]

Hrmmm I made a reply to this post and it seems to have disappeared....  anyways...  more I look at your string you MAY be better off slowing it down some and getting your efficiency back up.... looks like you're averaging about 25 psi per shot  and getting just barely over  1.1 fpe/cuin efficiency...   I have a feeling your pretty much way over hammered and could back way off on the preload and still not drop much speed....  be curious what it would do with some 10.5 gr pellets in there....  I bet your over hammered enough you wouldn't get much drop at all in speeds and maybe even pick up a few more shots....

typically I dont like to fire a pellet much faster then 920 fps.... if you want more power then that go to a heavier pellet.... your accuracy and efficiency numbers will thank you

[BigTinBoat]

Hrmmm I made a reply to this post and it seems to have disappeared....  anyways...

It's right here....

http://www.gatewaytoairguns.org/GTA/index.php?topic=110145.msg1052646#msg1052646

[robertr]

Right Michael, I did find a shorter slightly smaller diameter spring to try and got 100 shots using 9.5gr Winchester's with 680, 770, 687, 2000psi down to 800 or so, gauge was at end of green scale. I have checked all the springs I have at home, I guess i have to buy one.

[MichaelM]

Hrmmm I made a reply to this post and it seems to have disappeared....  anyways...

It's right here....

http://www.gatewaytoairguns.org/GTA/index.php?topic=110145.msg1052646#msg1052646

lol nope not that one... it was a response to shorty's post.......

Right Michael, I did find a shorter slightly smaller diameter spring to try and got 100 shots using 9.5gr Winchester's with 680, 770, 687, 2000psi down to 800 or so, gauge was at end of green scale. I have checked all the springs I have at home, I guess i have to buy one.

I believe the 1377 uses the same sized spring as the disco but with smaller wire...... its been a while since I have messed with my 1377 projects but I believe it does.....

maybe try increasing the gap more....

or just shoot it and be happy LOL!!! honestly trying to get as much efficiency out of something can just be a right PITA lol and sometimes not worth it....

[robertr]

 Yeah Michael I was just playing around with that short spring, I bet there was almost 1/2 inch of gap, I will have to make the rod longer if I want to use that short spring. So far I am still having fun tuning, should get back to some shooting I think though.