Hybrid short question topic

Harness the power of precision mixtures of pressurized flammable vapor. Safety first! These are advanced potato guns - not for the beginner.
User avatar
wyz2285
First Sergeant 2
First Sergeant 2
Austria
Posts: 2385
Joined: Sat Mar 06, 2010 7:50 am
Location: Porto, Portugal
Has thanked: 1 time
Been thanked: 3 times
Contact:

Sun Apr 01, 2012 6:26 am

Hi everyone.
As I started building hybrids, I loved it.
But changing burst disc it not fun at all :roll: so I took a little research about piston hybrids. But I really don´t understand how do they vent the pilot air when it fires :?: so I made 2 diagrams, the first one shows 2 type of piston hybrid valve that I thought would work, and the second diagram shows a fast venting chamber that I think will work both for hybrids and combustion.
Any thoughts? I think I won´t have problem machine the pistons out of nylon, but is nylon strong enough?
Attachments
fast venting chamber.png
fast venting chamber.png (15.75 KiB) Viewed 3650 times
hybrid.png
hybrid.png (17.6 KiB) Viewed 3650 times
CpTn_lAw wrote: :D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
User avatar
Alster370
Specialist 2
Specialist 2
Posts: 243
Joined: Mon Feb 21, 2011 9:34 am

Sun Apr 01, 2012 6:35 am

You could just use a reasonably strong spring inside the pilot chamber behind the piston, and add a small hole in the back of the pilot so the air can vent. Most people do this, as they tend to fill their cannons directly into the chamber.
User avatar
Fnord
First Sergeant 2
First Sergeant 2
Posts: 2239
Joined: Tue Feb 13, 2007 9:20 pm
Location: Pripyat
Been thanked: 1 time
Contact:

Sun Apr 01, 2012 8:29 am

Crowley and SB15 built the design of the right, mine is like the one on the left but without the popoff valve.

Both will work, but the one on the right will have less piston bounce. That means it's also critical to use a good bumper in this design. Nylon should be workable.

The quick-vent chamber is a very good idea, but in practice you may have sealing issues with the orings eventually. Hybrids get kinda dirty inside.
Make sure all threaded rods in the design are strong enough to take the forces involved.


Alster:
Been there, done that;

Image
Image
User avatar
D_Hall
Staff Sergeant 5
Staff Sergeant 5
United States of America
Posts: 1911
Joined: Thu Feb 07, 2008 7:37 pm
Location: SoCal
Has thanked: 6 times
Been thanked: 40 times

Donating Members

Sun Apr 01, 2012 12:29 pm

Another option would be a check valve in the pilot region that allowed air to flow into the main chamber.
Simulation geek (GGDT / HGDT) and designer of Vera.
User avatar
MrCrowley
Moderator
Moderator
Posts: 10078
Joined: Fri Jun 23, 2006 10:42 pm
Location: Auckland, New Zealand
Been thanked: 3 times

Sun Apr 01, 2012 3:48 pm

D_Hall wrote:Another option would be a check valve in the pilot region that allowed air to flow into the main chamber.
If I understand you correctly, that would only work if the pilot pressure was lower than pre-ignition pressure?

@Fnord, LOL. Been there, done that twice :D

As Fnord said, a good bumper is crucial to the design me and SB15 used. You also need a decent flow out the pilot valve to help stop piston bounce. I imagine that if you get piston bounce, your nylon piston will almost certainly break after a few shots. However, if you get everything right and piston bounce is not an issue nylon should be fine.

You will pay a bit in terms of performance but it should still be decent. I built a piston hybrid because I wanted a large hybrid and cutting out disks for a 2" union is crazy. I don't find burst disks too troublesome for my 3/4" burst disk hybrid; you just need to find what works. I use a modified union (tapered union face has been ground flat for more surface area to hold the burst disks), 4 o-rings all of the same size which stack up inside one half of the union and provide a seal and then 4 soda can disks with a very slight scored mark on them to help them burst cleanly at 10x.
User avatar
D_Hall
Staff Sergeant 5
Staff Sergeant 5
United States of America
Posts: 1911
Joined: Thu Feb 07, 2008 7:37 pm
Location: SoCal
Has thanked: 6 times
Been thanked: 40 times

Donating Members

Sun Apr 01, 2012 9:04 pm

MrCrowley wrote:
D_Hall wrote:Another option would be a check valve in the pilot region that allowed air to flow into the main chamber.
If I understand you correctly, that would only work if the pilot pressure was lower than pre-ignition pressure?
Or equal to. True, the pilot pressure could not be more than the pre-ignition pressure (plus a couple psi, depending upon your check valve selection).
Simulation geek (GGDT / HGDT) and designer of Vera.
User avatar
Alster370
Specialist 2
Specialist 2
Posts: 243
Joined: Mon Feb 21, 2011 9:34 am

Sat Apr 14, 2012 10:47 am

As im in the process of designing my own piston hybrid, would the top left diagram work without the pop off valve? I would assume that all the resulting gas would have left the chamber by the time the piston could react and return back to its position?
User avatar
Crna Legija
First Sergeant 2
First Sergeant 2
Posts: 2333
Joined: Sun Jul 20, 2008 5:14 am
Location: australia

Sat Apr 14, 2012 11:00 am

Alster370 wrote:As im in the process of designing my own piston hybrid, would the top left diagram work without the pop off valve? I would assume that all the resulting gas would have left the chamber by the time the piston could react and return back to its position?
Yes, but not as well as with a pop off you will diffidently get piston bounce that will demolish your sealing face/piston.
'' To alcohol... The cause of, and solution to, all of life's problems.”
--Homer Simpson

Add me on ps3: wannafuk, 8/11/11 cant wait
User avatar
Gun Freak
Lieutenant 5
Lieutenant 5
Posts: 4971
Joined: Mon Jan 25, 2010 4:38 pm
Location: Florida
Been thanked: 7 times

Sat Apr 14, 2012 2:52 pm

Image
OG Anti-Hybrid
One man's trash is a true Spudder's treasure!
Golf Ball Cannon "Superna"M16 BBMGPengunHammer Valve Airsoft SniperHigh Pressure .22 Coax
Holy Shat!
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 319 times

Donating Members

Sat Apr 14, 2012 2:54 pm

*word that BtB would chose to censor*

:D
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
MrCrowley
Moderator
Moderator
Posts: 10078
Joined: Fri Jun 23, 2006 10:42 pm
Location: Auckland, New Zealand
Been thanked: 3 times

Sat Apr 14, 2012 5:05 pm

Alster370 wrote:As im in the process of designing my own piston hybrid, would the top left diagram work without the pop off valve? I would assume that all the resulting gas would have left the chamber by the time the piston could react and return back to its position?
I wouldn't recommend it personally. I think it was ramses who used the "air spring" concept in his design, not sure how it worked out in terms of piston bounce.
jackssmirkingrevenge wrote:*word that BtB would chose to censor
It seems that BtB is more than happy to substitute his name for that word; now we have a synonym we can use :D
User avatar
Petitlu
Corporal 4
Corporal 4
Posts: 807
Joined: Fri Jun 03, 2011 4:52 am

Sat Apr 14, 2012 5:48 pm

Change of disk is fast on my hybrid (Thorjack), this is not a constraint because I put the bullet at the same time....
User avatar
MrCrowley
Moderator
Moderator
Posts: 10078
Joined: Fri Jun 23, 2006 10:42 pm
Location: Auckland, New Zealand
Been thanked: 3 times

Sat Apr 14, 2012 5:50 pm

It would suck cutting disks for a 2" union :wink:
It's annoying enough to spend 15min cutting 12 disks from a soda can that last only 3 shots at 10x.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 319 times

Donating Members

Sat Apr 14, 2012 5:51 pm

MrCrowley wrote:It seems that BtB is more than happy to substitute his name for that word; now we have a synonym we can use :D
hmmm...

"You utter Brian!"

Actually, it does have a ring to it :D
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
Petitlu
Corporal 4
Corporal 4
Posts: 807
Joined: Fri Jun 03, 2011 4:52 am

Sat Apr 14, 2012 6:00 pm

effectively is a long time ...
they are discs steel or aluminum?
Post Reply