Compressed air engine

Meaningful discussion outside of the potato gun realm. Projects, theories, current events. Non-productive discussion will be locked.
User avatar
Gun Freak
Lieutenant 5
Lieutenant 5
Posts: 4971
Joined: Mon Jan 25, 2010 4:38 pm
Location: Florida
Been thanked: 7 times

Wed Jul 27, 2011 3:55 pm

I'm trying to design a compresses air engine but I cannot wrap my head around how they exhaust the air in the cylinder in order for the piston to retract. Is there some sort of valve connected to the crank shaft that opens and closes? I can't find anything online.
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: 25836
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 157 times
Been thanked: 94 times

Donating Members

Wed Jul 27, 2011 4:05 pm

hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
velocity3x
Corporal 4
Corporal 4
Posts: 828
Joined: Fri Jun 05, 2009 3:09 pm
Location: Yuma, Arizona
Contact:

Wed Jul 27, 2011 4:06 pm

Gun Freak wrote:Is there some sort of valve connected to the crank shaft that opens and closes? I can't find anything online.
A good valve example is the linkage on a steam locomotive.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 25836
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 157 times
Been thanked: 94 times

Donating Members

Wed Jul 27, 2011 4:09 pm

velocity3x wrote:A good valve example is the linkage on a steam locomotive.
A bit more complex but worth a look, great website to browse through by the way.
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
Gun Freak
Lieutenant 5
Lieutenant 5
Posts: 4971
Joined: Mon Jan 25, 2010 4:38 pm
Location: Florida
Been thanked: 7 times

Wed Jul 27, 2011 4:20 pm

Now I need to figure out a way to implement that, but for lower pressure.
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: 25836
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 157 times
Been thanked: 94 times

Donating Members

Wed Jul 27, 2011 4:27 pm

Why should pressure have any bearing on the design, other than ensuring a sufficiently wide piston to provide the requisite torque?
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
Gun Freak
Lieutenant 5
Lieutenant 5
Posts: 4971
Joined: Mon Jan 25, 2010 4:38 pm
Location: Florida
Been thanked: 7 times

Wed Jul 27, 2011 4:34 pm

Well I just thought of a new design that doesn't need high pressure. A linkage runs off of the crank thank opens a small intake valve when the piston is I'm the retracted position. I think it is very promising but I need to draw up some sketches and hopefully one in 3D. I might post it.
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
ramses
Staff Sergeant 2
Staff Sergeant 2
Posts: 1679
Joined: Thu May 29, 2008 6:50 pm

Wed Jul 27, 2011 7:41 pm

Some of the more complex engines use variable valve duration to either fully expand the steam (air) for economy, or pump in full pressure steam for much of the power stroke for more peak power.

Do you feel like attempting something similar?
POLAND_SPUD wrote:even if there was no link I'd know it's a bot because of female name :D
User avatar
Gun Freak
Lieutenant 5
Lieutenant 5
Posts: 4971
Joined: Mon Jan 25, 2010 4:38 pm
Location: Florida
Been thanked: 7 times

Wed Jul 27, 2011 7:47 pm

How simple is it to construct that mechanism? I'm going to use this engine as a model but it will be a bit different. I'm just using the same valve setup.
http://npmccabe.tripod.com/coathngrengn.htm
Is it possible to vary the valve duration on this design?
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!
warhead052
Staff Sergeant 3
Staff Sergeant 3
Posts: 1769
Joined: Mon Mar 21, 2011 5:41 pm

Wed Jul 27, 2011 7:50 pm

Now I regret throwing out my old lawn mower engines. Try adding an air input line where the spark plug would normally go on a regular engine. And fill it with air, if it rotates then you have an air engine. You just have to drill a hole to let the air out.
User avatar
Gun Freak
Lieutenant 5
Lieutenant 5
Posts: 4971
Joined: Mon Jan 25, 2010 4:38 pm
Location: Florida
Been thanked: 7 times

Wed Jul 27, 2011 7:52 pm

It's not that simple lol.
Besides... The whole point is for me to build a model engine, for the fun. I'm also making a Stirling engine.
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!
warhead052
Staff Sergeant 3
Staff Sergeant 3
Posts: 1769
Joined: Mon Mar 21, 2011 5:41 pm

Wed Jul 27, 2011 8:08 pm

Ohhh, model engine. I thought you meant like an actual engine.

It may be that simple, I just haven't tried it. Soon as I see a neighbor throw out a mower I will try it though.
User avatar
Gun Freak
Lieutenant 5
Lieutenant 5
Posts: 4971
Joined: Mon Jan 25, 2010 4:38 pm
Location: Florida
Been thanked: 7 times

Wed Jul 27, 2011 8:11 pm

Cool, search on YouTube for Theairgunman. He has a video of a converted engine that runs on air/steam. Worth checking out.
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!
warhead052
Staff Sergeant 3
Staff Sergeant 3
Posts: 1769
Joined: Mon Mar 21, 2011 5:41 pm

Wed Jul 27, 2011 9:17 pm

Yeah, I am subbed to him. Its a pretty cool engine.
User avatar
Gun Freak
Lieutenant 5
Lieutenant 5
Posts: 4971
Joined: Mon Jan 25, 2010 4:38 pm
Location: Florida
Been thanked: 7 times

Wed Jul 27, 2011 9:27 pm

I'm subbed too! He did a very cool idea on his conversion.
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!
Post Reply