Tactical Inter-balistic Tennisball System

[chenslee]

Mods, please delete the other locked pictureless thread.

Thanks for everyone's' support! I had a great time building this.
I especially want to thank my wife who put up with me bumming around in the the garage WAY too much, especially since we had our first kid this year. She also put up with my incessant yammering about aluminum this, and fuel mixture that for the last 9 months. If it hadn't been for her reluctant support, this would have never happened.

I wanted a cannon that would fire multiple times with a minimum of effort. Barrel loading would not be acceptable. The cannon would also be unitized, portable, and would be free of external support mechanisms like air compressors. The ammo needed to be cheap, available, and abundant. The ammo needed to be of uniform size. The ammo needed to be non-lethal, i.e. not potatoes. The ammo needed to be re-usable. The propulsion system needed to use a medium that was easily obtained and economical. Parts for the cannon could not be milled. Parts for the cannon would be purchased, found, water jet cut plate, or fabricated by me.

What came out is this:


































Progress Photos









Cannon #2 and it's prototype older sister, the #1.



The secret to mixing fuel is just what the doctor ordered



The cannon was completely built, wire anchors, wraps and all, tested, then completely disassembled for painting.




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Pre-paint final build:
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First build before debug:
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For a build history: check out http://propanetennisballcannon.blogspot.com/

[Moonbogg]

This is a work of genius! Congrats to you for taking the gold and by a landslide none the less! Not only is this cannon cool, but I think it has a lot of potential as well to become a variety of different breeds. Good job and I am looking forward to seeing more from you!

[Hotwired]

AHA!

I was wondering what the heck the sprung steel ribbon coils were doing. Seem to be doing their job pretty smoothly

[Moonbogg]

Heres a rough idea of what can be expected if you decided to polish everything. I say go for it!

[psycix]

I agree, polishing would make this thing look as awesome as it is.

[chenslee]

Before anyone's heads asplode. Moonbog and I traded 3d models.

I'm sure he'll crap out a polished pump action hybrid golf ball repeater next year. By crap out, I mean amaze us all with his handiwork.

Or he might move on to something simpler like a pedal powered helicopter or a nano-scale fusion reactor.

[Moonbogg]

I'm sure he'll crap out a polished pump action hybrid golf ball repeater next year.

That would be seeeet.

[chenslee]

This is what it would look like if the plates and plastic were black. The cylinder bodies and structural aluminum are anodized. They would have to be sand blasted before polishing.

I think I'm getting the lighting wrong in my renderer. The black looks faded. Hmph

[Northir]

did or do you plan on releasing any kind of schematic for us ? i could see my self building this or something close to it after boot camp, seeing as how i have access to a water jet i could probably fab all the parts

[chenslee]

The water jet stuff is the easy part. Finding Parker 2MA2.50 cylinder bodies is not. This entire cannon was built around these cylinder bodies I raped off of some dud actuators.

I thought about putting together a drawing package and a parts list, but since I don't have a source for integrated tie rod cylinder body material, and I doubt you do either, it would be pointless.

2.5" bore air cylinders of this type and length cost in the $300 range, and you either need two, or one long one.

In other words, you would be better starting from scratch with a barrel material of your choice.

Here is a link to ebay's selection of 2ma cylinders. The only one on here that is worth a crap to me is the 2.5" bore 32" long one. That asshat wants $350 for a used actuator, and I already OBO'd him $200 for it and he refused. That was like 4 months ago. I expect that one to be on there forever.

rant:
Selling used actuators is like selling modified cars. It is VERY unlikely that you will ever find someone that wants YOUR actuator. There are literally hundreds of thousands of different configurations and mounting style combinations.

Most designers/engineers spec cylinders for a specific application based on their force and stroke. Not only that, but most designers/engineers are putting this in OEM equipment, or on equipment that is much more expensive than an air cylinder. It doesn't make economic sense for an engineer to be paid $40 an hour to look for used cylinders.

For these reasons, I'm appalled at the stupidity of people trying to sell used actuators at 50 to 75% of their list price. No one wants them. Not even new actuators.

[Brian the brain]

Hmm..it is slowly sinking in that a new generation of builders has arrived..

This forum is now more " tech" than Spudtech Forums ever was..

The average age has gone up dramatically compared to a couple of years ago..

I'm wondering however if you will be building any more models..
I'll be on the edge of my seat for your next cannon, that's for sure.

Well...back on topic..
Why did you build the front handle like you did? Couldn't it be attached to the barrel directly and save weight?
Do the rails have some other function I'm missing?

[chenslee]

ROFLSPNKER



Actually the front grip and bar are attached to the breech bolt. It's what feeds balls,actuates the fuel valve, and opens the air ports.


There are two plastic slider bearings that fit into the aluminum profile. One is shown here, under the breech bolt, and the other is runs on the side of the grip slide.


I had to buy a $40 counter bore to make this screw configuration work.

I have NO pictures of the longer slide bearing, but it is the reason for the extra material past the grip, and the 1x2 block of material next to it.

There will be a third cannon. I can feel it.

[Moonbogg]

You can still sell exploded assembly drawings of it and they can improvise the barrel as you stated.

[chenslee]

FYI. There is a third cannon in the works. It is a from-scratch design and a new configuration that eliminates ALL found parts and replaces them with commercially available items.

Moonbogg, there will be no plans available. Partly because I'm too lazy to make a package of prints and write 20 pages of instructions. However, the third cannon is being designed for sustained marketability.

[Moonbogg]

I look forward to it. If you can manage to improve what you have already created its just going to be even more impressive which is already bordering on ridiculous My only dislike of this design is that it could be more powerful. I don't know if more power is one of your criteria, but it would make it much more impressive and attrative to buyers IMO. Better yet, adjustable power.