The sound could be made even more silent if a polyurethane or rubber disk (3-4 mm) would be inserted to accept the piston after hydro braking.
Thanks!
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Tomba - All in One barrel sealing
- Thread startertromic
- Start date
Thread Status: Hello
, There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.
It can take a long time to get an up-to-date response or contact with relevant users.
The sound could be made even more silent if a polyurethane or rubber disk (3-4 mm) would be inserted to accept the piston after hydro braking.
Thanks!
During loading the shaft, on distance "a" undesired water is being removed from the muzzle. On distance "b" water for hydro shock absorber operation is injected into the muzzle. All this water (a, b) would be undesired/harmful in guns with classical shock absorber of any kind.
I have got an idea that this design has an additional benefit. Water that serves for braking the piston actually accelerates the shaft or at least facilitates separation from the piston without losing aditional energy.
Cyrano is 11 mm as well as Sten 11 or One Air (11,2). If this system would work good it will be excelent. Its ready for new test, tomorow, I hope. I will tray with sealed elastic tubing over muzzle ports, as last time. I made some changes to shock absorber body so I expect even less noice. The most difficult task will be to pump the gun to 20 - 25 bar.
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Looking good. It did not look as it gave any problems with the non-flexible blockage of the muzzle water exit holes. Will there be a tiny air-bobble in these even though you fill the muzzle with water?
As last time is it hard to evaluate the sound from the video. What was your impression?
You held the spear tail towards the camera.. I could not see its details... Have I missed something here?
Thanks,
Jegwan
As last time is it hard to evaluate the sound from the video. What was your impression?
You held the spear tail towards the camera.. I could not see its details... Have I missed something here?
Thanks,
Jegwan
You are right. There were no problems with the non-flexible blockage of the muzzle water exit holes. That is because the water can replace the free space behind shaft tail when the shaft separates from the piston. Average speed of the shaft is maybe more than 2.5 x average speed of piston during breaking. But this solution would be best with muzzle without water exit holes. It is difficult to have good sealing using elastic tubing because the inner pressure of water being injected is very high, same as pressure in a gun. It is hard to evaluate the sound from video.
This might be a modification (possible with elastic tubing over muzzle water exit holes) My idea was not to change the original piston and to use shaft with normal taper end. In addition, rubber tubing from normal shock absorber would be used too, so this would be two stage shock absorber: first hydro shock absorber, and than normal shock absorber. At the time when rubber shock absorber begins its action, shaft tail should be leaving shock absorber. Shaft tail end should be modified so water injection (or water suction) for hydro damper would be accomplished. Water injection would be choice with muzzle without water exit holes or with sealed elastic tubing over exit ports. Water suction would be choice with elastic tubing (acting as valve) over muzzle water exit holes.
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Principle of operation:
Average speed of the piston during braking in hydro damper is about 1/3 x speed of the shaft. That is about 10.3 m/s if the speed of the shaft is 30 m/s. Ive got this result from calculation assuming that the braking deceleration is constant.
Average speed of the piston during braking in hydro damper is about 1/3 x speed of the shaft. That is about 10.3 m/s if the speed of the shaft is 30 m/s. Ive got this result from calculation assuming that the braking deceleration is constant.
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Here is a useful suggestion regarding TombaF.
http://forums.deeperblue.com/pneumatic-spearguns/97200-airbalete-cyrano-evo-hf-2.html#post904778
http://forums.deeperblue.com/pneumatic-spearguns/97200-airbalete-cyrano-evo-hf-2.html#post904778
Here is a link to brief review of key points about Tomba. I made this using copy/paste from this long thread.
https://www.dropbox.com/s/x8x9r64o0kuxhxh/Tomba.pdf
https://www.dropbox.com/s/x8x9r64o0kuxhxh/Tomba.pdf
Hope this is not out of place on this thread but, just wanted to publicly pass on my thanks to Marko/Tomislav for the Tomba F700 I've just recieved.
Comms, delivery, and quality are first class. Fitted up to the gun with zero issues.
Not used in anger yet but, if it performs to the standards already set it should hopefully be very sweet.
A well thought out designed and manufactured product.
Many thanks to you both.
Comms, delivery, and quality are first class. Fitted up to the gun with zero issues.
Not used in anger yet but, if it performs to the standards already set it should hopefully be very sweet.
A well thought out designed and manufactured product.
Many thanks to you both.
