SpudFiles

I was thinking of mounting a small combustion to a robot but the recoil will have no where but into the robot with would result in shaking and possible damage to the robot.

My solution is simple but will there be enough recoil for this to work?

I basically thought of getting about 3ft of 2in pvc, For the barrel and chamber all in one, with a spark gap at the back. Then i will get about a 1ft section of a pvc coupling pipe for the barrel to slide in and out of with some elastic bands tided to the coupling and launcher.

When the gun fires the unit will blowback like a gun and the whole barrel will move back which will slow with elastic bands and then return. Even if it doesn't control recoil well it would be one hell of a cool gun!

why not just have it sit in a U shaped mount and have a spring behind the cannon? it would be much more simple.

yeah, that way the whole gun would move and bounce back instead of having to make a bunch of different measurements and plans for the recoiling barrel...
I still like the idea though, I've seen it done many times in different forms on real military weapons to minimize recoil for the tanks and humvees.

That would reduce the recoil a lot but if the blowback isn't strong enough to compress the spring the force is just translated to the spring into the robot.

I could use weaker springs but my homedepot doesn't carry a large assortment of springs.

Its not all about recoil reduction anymore, its works either way but I think that sliding barrel adds a really cool effect. Plus rubber bands are weak and adding more or less will increase

Just like military howitzers where the barrel moves backward when fired for recoil reduction. Same principle but it would be a damn cool gun.

Just imagine how cool it would be to see a robot launch a potato in slow mo with a blowback barrel!!!!! That would be freaking sick, it will be called the mini howitzer he he he he he..............................................

yeah, it would be pretty cool..

and you wouldn't necessarily have to use springs, you could also use bungee-cords, elastic suspenders, etc...

just anything that can take the shock and recoil, and is strong enough to move the cannon back forward to where it was... you could even use those elastic book covers they make...i always fling pencils across the class room with 'em he he he...

I was gona use rubber bands anyway just because they are cheap, breakable, and you can add more or take away some to add extra force.

That may be your best bet for something small scale.

Blitz wrote:That may be your best bet for something small scale.

Hmm, if small enough, you could have a pile of clay or rubber putty behind the launcher.
When it kicks back, the back of the launcher would embed into the putty, which absorbs the shock.
NOTE: ALOT of putty

I think that with a good muzzle break the recoil would be neglectable.
Recoil isnt that much on normal combustion cannons.

I read an article about a development by the army to produce a recoiless gun (kind of). Instead of absorbing it, the prototype redirects the direction of the energy downward. The bolt is linked to a linkage arm that is conected to a vertical moving weight postitoned where the clip would typically be on a regular gun. I'm sure you questioning whether jeking the gun up instead of back improves accuracy & lowers recoil. The answer is so am I. The article I'm recalling is very vague in my memory. I think it was in an issue of Popular Science or Popular Mechanics. I'll see if I can find it online to further aid you.

http://www.spudfiles.com/forums/viewtop ... tml#106725

Check this video out. In one clip, it shows some sort of spring/shcok absorber setup that allowed the cannon to slide back through some ploymer-looking blocks. Maybe you can ask him about how he did it

edit: look at 3:49 in the video

Spudgun on Crack wrote:I was gona use rubber bands anyway just because they are cheap, breakable, and you can add more or take away some to add extra force.

Don't use rubber bands. They are too much of a PITA. You'll get it all working then not use the gun for a couple months and the rubber bands will have degraded and'll fall apart when used again.

Go to your local hardware store and get a set of bungy cords. You can urually find'm in sizes that range from a couple inches long up to several feet.

The most elegant way to do it would be to get a pair of small air shocks (perhaps like the ones for car trunk lids). That would make the gun look like a real arty piece. ("arty" as in artillary, not as in art).

http://www.surplusshed.com/pages/item/m2421.html
http://www.surpluscenter.com/item.asp?U ... tname=misc
http://www.surpluscenter.com/item.asp?U ... tname=misc

Build a qev cannon and direct the exhaust backwards, then fill the exhaust pipe with water.
You will have recoil countered by water rocket.In a nutshell..

Cool ideas but i am trying to go simple and cheap, I don't really have a lot of money to put into building these so I have to make due.

I will either use bungie cords or those car shocks.

The only problem with the car shocks is that they take a lot of force to compress them really fast which i doubt my gun will have a lot of force.

Would it be possible to say drill a hole in the back of the cylinder to allow more air to escape so it could be pushed back easier?

Its starting to sound like a really cool gun!!!!!!!!!!

Why dont you first try it without recoil absorbing? It might not even be needed.
And if it is needed, drill a few holes in the barrel near the muzzle so that the gas can escape trough the sides, instead of slamming out to the front.