Tuning Finished up on my Impact barrel tension mod.

Don't know how this thing can shoot any better but I just had to try and make the barrel a bit more stable. 

So I made an adapter with an o-ring inside, out of Delrin, pretty much like the stock adapter at the rear of the shroud but no threads instead it just pushes into the carbon fiber tube and butts up against the trigger block. Pretty simple way to do it.

Then I modified an old damaged shroud adapter to fit in the carbon tube. Cut the tube a little long, by a bit less than an eighth of an inch, so when I tightened down the front shroud/barrel adapter it would pull forward on the barrel.

It really werqed well the barrel is crazy stable now. I have been careful not to over tighten it cuz it is pulling against the single set screw, holding the barrel, at the rear block. Guess I will be adding a second set screw on the other side soon. I started this a couple months back but didn't have all the parts to make it look this nice. So managed to hold off with the post until I got it all together

Don't know how it's going to shoot. I have some flu bug so with the exception of running through the fast food drive through I am self quarantined for at least another week or so. This is my second flu bug since the China Covid started.







Modified shroud adapter for the front I ended up making the rear one out of Delrin. Fairly thin walled one inch, actually it's 23mm ID, 25mm OD, carbon fiber tube that I have had around for years just waiting for something like this. I used 25mmID, 27mmOD carbon tube on the second one. It werqs well and is closer to the size of the original shroud so the shroud to moderator adapter does not need to be turned down as much.







Looks good and the 700mm barrel is now more than secure and doesn't droop or move around at all.



Ernest did a similar mod a few weeks after I did mine. Or at least he did a video on it then anyway no telling when he actually did the mod.









https://www.youtube.com/watch?v=OxMoNqUguX8








 
Biohazardman looks great!!!!I

I'd be tempted have some fun with your lathe and the 4 jaw chuck. build a new block that tied the front cocking block with carbon fiber tube using a 0.001 press fit inside your carbon fiber tube, I'd for get putting O-rings in the front block maybe add your grub screw there.

Screenshot 32.1652190856.png


Epoxy glue the joint, much like how a mountain bike frame is built.
 
How that would be possible to make a "collar" for the liner both ends, and stretch it out inside barrel like a guitar string, instead of pulling the barrel tube? I don't think you can apply enough force to stretch a tube length 30 microns = 0.001" ??

I can only imagine that would be possible in FX lab only.

Maybe some sort of compression fittings that "grab" the liner. 
 
Mrshosted

That looks good. I was thinking along the line of a carbon fiber barrel housing instead of steel. Then using the same compression type affair used on the Crown with the light barrel to secure the liner front and rear.

Just a thought it is for now though as I was thinking about saving some weight but with those hefty brass compression nuts I would not likely save much if any.
 
Don't know how this thing can shoot any better but I just had to try and make the barrel a bit more stable. 

So I made an adapter with an o-ring inside, out of Delrin, pretty much like the stock adapter at the rear of the shroud but no threads instead it just pushes into the carbon fiber tube and butts up against the trigger block. Pretty simple way to do it.

Then I modified an old damaged shroud adapter to fit in the carbon tube. Cut the tube a little long, by a bit less than an eighth of an inch, so when I tightened down the front shroud/barrel adapter it would pull forward on the barrel.

It really werqed well the barrel is crazy stable now. I have been careful not to over tighten it cuz it is pulling against the single set screw, holding the barrel, at the rear block. Guess I will be adding a second set screw on the other side soon. I started this a couple months back but didn't have all the parts to make it look this nice. So managed to hold off with the post until I got it all together

Don't know how it's going to shoot. I have some flu bug so with the exception of running through the fast food drive through I am self quarantined for at least another week or so. This is my second flu bug since the China Covid started.







Modified shroud adapter for the front I ended up making the rear one out of Delrin. Fairly thin walled one inch, actually it's 23mm ID, 25mm OD, carbon fiber tube that I have had around for years just waiting for something like this. I used 25mmID, 27mmOD carbon tube on the second one. It werqs well and is closer to the size of the original shroud so the shroud to moderator adapter does not need to be turned down as much.







Looks good and the 700mm barrel is now more than secure and doesn't droop or move around at all.



Ernest did a similar mod a few weeks after I did mine. Or at least he did a video on it then anyway no telling when he actually did the mod.











https://www.youtube.com/watch?v=OxMoNqUguX8










I played a bit more for fun

,
Screenshot 34.1652193506.png


Add two barrel locking set screws and chamfered the edges

Would be nice to incorporate a way to also secure the barrel at that point. I ordered one of the "barrel holders" from that air rifle group in Saudi I think. Gonna butt up CF into it. 
 
 Just a thought. 
If the barrel is stretched like a guitar string. Why wouldn’t it vibrate similar to a guitar string.I believe this may have a higher frequency.

I would imagine, but have no way to prove. Compressing the liner would translate to a lower frequency. I believe a lower frequency, would be easier to manage.The lower frequency has a slower wider Sine wave. Allowing the shoot to be more repeatable.

Just food for thought.
 
Just a thought. 
If the barrel is stretched like a guitar string. Why wouldn’t it vibrate similar to a guitar string.I believe this may have a higher frequency.

I would imagine, but have no way to prove. Compressing the liner would translate to a lower frequency. I believe a lower frequency, would be easier to manage.The lower frequency has a slower wider Sine wave. Allowing the shoot to be more repeatable.

Just food for thought.

Seems logic in it. But may be the barrel is strectched so much that there are immaterial vibration.
 
Pretty neat. Why not just get the carbon tube thick enough so it just fit over the barrel. Not sure that little bit of volume would do much for the sound suppression but interesting to see. If anything I would love to see a solid barrel from liner out. 


another thought or question is has anyone thought of making the front block with hole big enough to run a tension tube all the back to the action, that to me would work better but the block itself is rather small. 
 
............. lower frequency has a slower wider Sine wave.............

...........

Also....high frequencies are and staying local, low frequencies travel further - through connected parts. Lower then 30 Hz can brake parts, in a ballpark of 18-19 Hz the welding brakes. It is an old video (shall be able to find it on YT these days) from many decades ago when a bridge collapsed because of army was marching across.
 
I don't see compressing working as nice as tensioning. I'm not sure a guitar string makes sense to compare to. Push the 2 ends together and you get a bow in it and is floppy. Shoot a projectile through that. Then pull them apart and it's taut. That's the one I would choose. 

Now a barrel is a solid material not floppy but putting under compression to me still makes sense that it wouldnt be as good as tension. But that's just my thoughts on it. Could be wrong 
 
I personally like a solid free floating barrel. 

Bhaur

I’m with you on this, unfortunately the FX barrel system is anything but solid. I’m not sold on the compression concept but I did preorder a one of their kits to try out. Anything to strengthen the barrel has got to be a plus imo. That being said, I would rather see them develop a system that would tension the liner.