SSG tuning.

[freddieP]

"Rami939"It's a SlingShot Hammer .
It was developed or patented by Daystate,I think ?
For what I've read, this SSG system is based on that concept .
Please correct me if I'm wrong .

The slingshot is a two piece hammer. The outer driven by the main hammer spring contacts the valve face and the inner is then slung forward and contacts the valve. The inner is sprung, connected to the outer. The GTA thread does compare the two. Rsterne does a much better job explaining the SSG but in short here it is below:

The SSG as shown in the picture AJ shows is just a hammer spring on a guide. It is compressed when cocked. Propels the hammer forward upon sear release but then the spring stops extending as limited by the guide. The hammer continues to coast a short distance to where it hits the valve.

In a normal setup as the valve closes it propels the hammer back, compressing the main spring and the main spring shoves the hammer back into the valve releasing more air, wasting the air..

With the SSG the valve closes and sends the hammer back but its coasting back without compressing the mainspring and hammer/valve bounce is eliminated.

 

[ztirffritz]

"glengiles"so if you have a Hatsan this isn't a viable tuning option?

If you read through the (currently!) 18 pages on the GTA thread, they've made a few attempts to make it work on the AT-44, but it's much more complicated. Every adjustment requires disassembly. A few people have put forth some ideas or suggested they had ideas for how to make it work, but so far no one has had much luck.

 

[glengiles]

Thanks. I'll pass then.

 

[JohnL57]

Verrry interesting! Could be a boon to guys like me who tune for less power/lower pressure fills. I currently use a NBLT tune on my .25, does ok, but only getting 16-20 good shots. Does the hammer travel past the spring on firing like the Harper slingshot? Or does it just barely contact the valve stem? 
Thanks,
John

 

[30cal]

The hammer has no restriction on travel. It is free to hit the valve until the valve stops it. The spring is captured and so stops pushing the hammer when the spring guild reaches its stop. The hammer then continues on under its own momentum to hit the valve.

 

[Dan25]

Just a thought on the subject of no bounce hammers for those technically inclined. How about a reverse hammer sear catch. A traditional swing hammer like a revolver is my thinking. When the hammer is cocked the spring loaded reverse sear would be mechanically pulled away from the base of the hammer allowing the hammer to hit the valve stem upon firing. When fired the reverse sear would be released to catch the hammer and prevent it from restriking the valve stem and wasting air. When you cock for the second shot a lever would retract the sear allowing the hammer to strike the valve stem. All it would take would be a few levers and good engineering. I guess you could design a catch that would work with the traditional hammers like found in the Marauder. I am not an engineer or even good with anything more than algebra but the problem is multiple hammer strikes on the valve stem. Why not a simple reverse hammer sear that would mechanically prevent multi strikes? This would have to be a factory design.

 

[ajshoots]

The WAR no bounce hammer has a somewhat similar approach in that it has break shoes that completely stop the hammer after the initial valve strike.

 

[ksfastman]

AJ

Bob's SSG has a drilled out bolt to set clearance, it doesn't appear you have that feature? 

 

[ajshoots]

Not following you?? The ssg is set by the nut behind the end cap.

 

[ksfastman]

It appears Bob uses a drilled out bolt to move the spring and guide in or out independent of the preload. But you seem to be obtaining the same results without that feature 

 

[ksfastman]

Maybe I'm missing something

 

[freddieP]

Is the original hollow hammer spring adjusting bolt still present in the cap? It can be used to adjust the position of the SSG assembly with respect to the at rest position of the hammer resting on the valve. Although I don't know how it'd be turned w/ the SSG in place

 

[ajshoots]

ksfastmanMaybe I'm missing something

I very well could be the one that missed something. I didn't read every post on the GTA thread and haven't followed it since making my own ssg. I can still adjust the hammer spring preload and the overall length of the ssg with mine, but everything has to be taken apart.

Since I don't make parts to sell, my only interest has been getting results. I am certain that others have designs that not only look better but are easy to adjust as well with possibly added features.

FreddieP, I used the factory hollow spring guide, but had to drill it out some so the ssg could slide smoothly. And yes, you have to take the ssg apart to adjust hammer spring preload. Again, this is just how my ssg works and not sure about others?

 

[freddieP]

Nice. I'm looking forward to work backing off so I have some time to try out the SSG.

AJ for a hardware store job yours looks very nice.

AJ, does the cap nut go into the hammer recess nicely w/o drag or catching... did you drill out the hammer at all or just shorten the striker?

It'd be nice to come up with a spring adjuster that extended out the back of the cap and had wrench flats on it. With my basic hand tools tho it'd be pretty hard to do a good job of drilling out a bolt.

 

[ajshoots]

The acorn nut doesn't drag at all. I only cut off the striker and didn't enlarge the hole in the hammer.

The first one I made, I didn't even cut the striker or do any other mods. Just cut a hammer spring down to the length minus what room the striker took up in the back of the hammer. Used 8-32 all thread without a polytube cover and it actually worked damn near just as good as making one as I showed in the pictures which also included cutting down the striker and opening up the hammer spring guide/adjuster in the rear cap.

I thought that I could make gains by making the ssg fit inside the hammer and use the poly tube over the all thread to reduce drag. Apparently my really crude ssg functioned just as well as my final product. So, there are even simpler ways to make a working ssg. All in the amount of time you want to invest. I will run out and take a picture that might illustrate better

 

[ajshoots]

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This shows a stock length spring and the length I cut the spring down for my first ssg attempt.

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This is how the ssg fit without cutting down the striker.