SpudFiles

mattyzip77 wrote:Instead of making the cannon look like its recoiling hard, why dony you make a cannon that actually does have a badass recoil??? Just sayin>>> :sign7: :sign7:

Well since they are shooting nerf howlers, which are relatively light, it would be difficult to get a cannon so large to have significant recoil.

The first idea that pops in to my head is having the inline cannon on some low friction tracks with a large pneumatic ram; or perhaps two smaller ones. Have some air divert out the barrel in to the ram(s) so that they extend and push the gun back on its tracks. Seems pretty straight forward to me, how well does it suit your design? I imagine there would be some difficulty with timing the air being diverted in to the rams so that it is in sync with the projectile firing. Perhaps you can have an auxiliary tank just for the rams.

The other option is just to have the gun on low friction tracks and see if whatever recoil is present is enough to push it back. I doubt you would get an 88-like recoil from this as the gun would roll back rather than shoot back as with a ram.

Edit: Look up homemade camera dollys for ideas about low-friction tracks.

Good idea crowley! I may try that. What if I used a QEV with a 3 way ball valve pilot, so when you reset the main valve you also reset and fill the AUX tank for the recoil system, see what I'm saying? That way when you pull the string, its easier to adjust timing for it.

Add a bag of water/flour or something like that to the shot. It would most likely burst in the barrel, giving a nice smoky mist muzzle flash and a ton of recoil. You'd be slowing the nerf rocket down with it, but you'd just have to find a trade-off zone you're happy with.

Crowley's idea is good, and you could always combine it with this approach if they are not effective enough individually.

Yeah that could work. If you had the small valve on the aux. tank also hooked up to the main gun valve, so that both are piloted at the same time, you could get a synced recoil and gun firing action.

I haven't worked with pneumatic rams so I have no idea how much air it would take to get a big ram moving at a decent pace.

I like Fnord's idea as well; shouldn't be too difficult to get some smoke effect going on without hampering performance significantly.

edit: I've always wanted to know what kind of injuries the 88's recoil has inflicted on some poor soldiers. Broken bones for sure.

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Yeah, the 88 is pretty much what I am aiming for, but not that big haha.

Fnord, I will try that idea.

If you guys have any brain waves that may aid, please let me know. Thanks for the info so far, I will get started as soon as possible.

This may seem implausible, but Im just throwing around some ideas for a powerful recoil system...

So, assuming you can use a piston valve or QEV for your main valve. First you turn your chamber into a giant air ram, but due to the size, instead of a spring steel spring we'll use an air spring (unless you can source large steel springs of course) So you trun the air chamber around so that its facing backward (opposite direction of the barrel) and fill the QEV/Piston through a push button DCV hooked up to constant air.

When you fill the air chamber, your air ram will push the gun forward slowly along a track. Then, when the gun is fully charged in the forward position, you actuate the DCV (in your case with a string looped around it that depresses the button when you pull the string)

When the gun fires, the air spring (or steel spring) will push your cannon back (how hard will depend on the spring strength) in order to mock recoil. When you the let go of the string, the chamber begins to refill and the cannon returns to the forward, primed position.

I hope that makes sense without an illustration, but I can certainly provide one if you've got interest in this design

MrCrowley wrote:edit: I've always wanted to know what kind of injuries the 88's recoil has inflicted on some poor soldiers. Broken bones for sure.

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That's just a 57mm...

what about you use a heavy as captive piston that will make it recoil like crazy and still be weak enough to not hurt people.

captive piston hitting the end of the barrel will push it forward though...

jackssmirkingrevenge wrote:captive piston hitting the end of the barrel will push it forward though...

Not if you put a good bumper on the end witch it would need.

You're still hitting it with a fast piston in a forward direction though, bumper or no bumper.

http://smith-wessonforum.com/blogs/29-1 ... l-gun.html

Yeah, I want the recoil to go backwards Crna. Good idea, but it won't work.

hmmm,

a "normal" coaxial has a piston wich travels backwards upon openingen...

make that heavy, and you got more recoil....


or

the gun needs to be on sliding tracks anyway to get the desired effect...

you could use these "rails" as youre airram.

make it so that you fit smalled diameter pipe into a larger one. make it so that it returns to its neutral state with springs, or rubber bands...

feed the airrams from the beginning of the barrel...

if you make te spring stronger, the recoil will be less... and vica versa..


quick sketch:

Quark, that may work.

I found out from the captain he has 2 7' sections of 3" ID galvanized steel pipe I can use, so I solved that problem. Going to get access to a welder at some point, and I will weld a plug to one, and add gauges and safety equipment to one, and then weld adapters to the end of each so I can attach the ball valve. Then I will get started on the recoil system. I hope this is light enough to be pulled around...

when teh air ram comes to a stop same problem as captive piston witch will so work , yeah it will recoil forward but so much less then backward you wont notice it.