40mm Rubber Bullet gun VIDEO UPDATE

Leonard · Mon May 11, 2009 11:08 am

Incredibly awesome gun! As usual. May i ask to be linked to a page that would contain details of the internals, valves, etc...? (or suggested to do some research on a personal site if you have one) Im just very curious about it.

Carlman · Mon May 11, 2009 11:29 am

Wow mate! Another great gun! Well done

Solar · Mon May 11, 2009 2:00 pm

http://www.eclipselauncher.com has a little more info about the base launcher. I will be revamping soon and have a forum for users as well as tech papers, etc.

jagerbond · Mon May 11, 2009 2:35 pm

Rory,
Awesome configuration on already super advanced gun. I was watching your videos and was thinking you should try using helium for your compressed charged. According to GGDT it looks to make some big differences in velocity.

Where do you get your anodizing done?

Mike
Sureshot Inc. / http://www.ultimatespudgun.com

Solar · Mon May 11, 2009 5:03 pm

Anodizing was done at a place called Production Plating in Mukilteo, Washington. Not sure it needs to fire a faster round just yet...

POLAND_SPUD · Mon May 11, 2009 5:14 pm

@solar
ohhh.... does it use an air cylinder to move the bolt ? and how does it close the bolt just before firing the gun ??

Ragnarok · Mon May 11, 2009 5:28 pm

jagerbond wrote:According to GGDT it looks to make some big differences in velocity.

Actually, my experimentation with my Apocalypse modeller shows that use of helium won't make a vast difference unless you're already talking about pretty fast velocities - if you're not exceeding about a hundred and fifty metres per second, you won't notice the difference.

Actually, under some circumstances, it's very possible for helium to harm velocity, because it's got a higher ratio of specific heats than air does, which means that it cools more (and loses more pressure) for the same ratio of expansion.
Generally, less than one hundred metres per second, helium can actually reduce performance.

As a general rule, Air beats Helium at lower velocities, and at higher velocities Helium can beat air... but at decent pressures and velocities between 300-500 fps, you won't notice the difference.

Also, as I can't see the Eclipse being underpowered for what it's doing, so there's probably little need to spend more money on helium rather than Air or CO2.

Hotwired · Mon May 11, 2009 6:09 pm

POLAND_SPUD wrote:does it use an air cylinder to move the bolt ? and how does it close the bolt just before firing the gun ??

Trigger valve fires the cannon by allowing 300psi air through an airline into the back of the main valve.

To make the bolt close first the bolt cylinder is connected to the airline before the main valve.

I can't tell if the airline continuing from the bolt cylinder is staggered back from the airline going in or even at the end of cylinder piston travel to guarantee the bolt is shut before the main valve fires. Might be.

inonickname · Mon May 11, 2009 6:39 pm

I don't know if he wants more velocity (unless this is a deviation). Sub lethal launchers tend to be solar's thing.

sssssbooom · Mon May 11, 2009 11:03 pm

that is amazing. so do you work at a machining shop or something?

Tony.Knaak · Tue May 12, 2009 1:06 am

You are a great inspiration, thanks for sharing your guns!

I wish I had the resources and ingenuity to create a gun with that much craftsmanship.

rikukiakuchiki777 · Tue May 12, 2009 2:50 am

Excuse my stupidity, but can someone please explain in detail how the valve works, keeping in mind I don't know all that much about pneumatic cannons, so simple is good.

Technician1002 · Tue May 12, 2009 3:08 am

rikukiakuchiki777 wrote:Excuse my stupidity, but can someone please explain in detail how the valve works, keeping in mind I don't know all that much about pneumatic cannons, so simple is good.

A good place to start it here;
http://www.spudfiles.com/spud_wiki/inde ... c_launcher

Follow the links to the common elements section on valves to see the operation and merits of the various valves from ball, sprinkler, diaphragm, to piston.

I just completed some edits to the piston valve page which may help.
http://www.spudfiles.com/spud_wiki/inde ... ston_valve

inonickname · Tue May 12, 2009 4:32 am

sssssbooom wrote:that is amazing. so do you work at a machining shop or something?

I believe he does this for a living, so yes.

jagerbond · Tue May 12, 2009 6:44 am

Ragnarok wrote:
jagerbond wrote:According to GGDT it looks to make some big differences in velocity.
Actually, my experimentation with my Apocalypse modeller shows that use of helium won't make a vast difference unless you're already talking about pretty fast velocities - if you're not exceeding about a hundred and fifty metres per second, you won't notice the difference.

Actually, under some circumstances, it's very possible for helium to harm velocity, because it's got a higher ratio of specific heats than air does, which means that it cools more (and loses more pressure) for the same ratio of expansion.
Generally, less than one hundred metres per second, helium can actually reduce performance.

As a general rule, Air beats Helium at lower velocities, and at higher velocities Helium can beat air... but at decent pressures and velocities between 300-500 fps, you won't notice the difference.

Also, as I can't see the Eclipse being underpowered for what it's doing, so there's probably little need to spend more money on helium rather than Air or CO2.

Thanks for the Helium info.

With that said, what is the performance parameters of the eclipse? I see the specs say 50-1200PSI what velocities have been achieved? Have any other gases been experimented with at higher velocities?