SpudFiles

Cannon #4

Cobra Striker

Second Place Winner!

Final Judges Score Chart
-Idea 13/20
-Use of materials 5/5
-Creativeness 5.5/10
-Quality of build 4.8/5
-Function 7.3/10

This cannon is part of the SpudFiles Innovative Contest. For details see here...
http://www.spudfiles.com/forums/spudfil ... 19233.html

--Details and pictures from cannon builder--

The idea behind the Striker was to create a high-end hybrid cannon that was cost effective, able to be home made and very easy to use while being compact yet very powerful. Fast cycle times and ease of use were paramount in the Striker design.
The Cobra Striker is a fully self contained 5X oxy/mapp burst piston hybrid cannon. It is all aluminum and features a break barrel design for ease of transport and storage. The cannon uses a piston with ventilation holes in it and the piston is seated behind the front end cap of the combustion chamber. The piston is held back with spring plungers and the piston is sealed with an o-ring, keeping the chamber air tight until the piston opens. The piston is restrained to hold in pre ignition gasses, but when it opens it stays open, ensuring all pressure is released.
The chamber is purged with o2 and then the piston is pushed closed, sealing the chamber. The chamber is then loaded with 5x worth of mapp gas and it is ready to fire once the golf ball or other projectile is loaded. Cycle time is very fast and the cannon can heat up pretty quickly, so its important to try to limit your shots per minute.
The cannon is innovative because it features many things in a single cannon. The features of the cannon are as follows:

The cannon was made with not a single professional machine tool or service. Drill press, sand paper, hand taps and a saw was about all that was required. This cannon was designed with cost effectiveness and achieveability in mind for the average spud gunning enthusiast.

Integrated mapp meter pipe is part of the support structure.

Pushbutton mapp gas injection

Cannon is a self contained 5x hybrid (can be used at lower levels as well)

Break barrel design

Breech loading

Very fast and effortless cycle time

Cannon is all polished aluminum

Cannon has no wires visible and very little fuel hose visible

Cannon has a perfect fitting aluminum golf ball barrel

Barrel/breech is designed with a chamfer to also cut spuds easily and channel away the extra potato pieces

Innovative support structure allows free adjustment of handle positions

Triple spark gap stun gun ignition

Cannon is designed for ergonomics and was created along side a rifle stock for dimensional compatibility with the human body. It is designed to be held comfortably at the shoulder while being held like a rifle, or shot from the hip with dual hand grips.

Although not yet implemented, the cannon has ideal locations for installation of laser sights and shoulder slings.

Cannon is very compact with only a 3 ft barrel, yet is more powerful than full size combustion cannons allowing the user to have his cake and eat it to.

See following photos and video link.







































Chamber fans cannot be used with the Striker for the following reasons:





[youtube][/youtube]

Idea - 10

The idea behind the Striker was to create a high-end hybrid cannon that was cost effective, able to be home made and very easy to use while being compact yet very powerful. Fast cycle times and ease of use were paramount in the Striker design.

While I do think the builder has captured this intention, I do not see anything innovative.

Use of Materials - 5
The materials are well put together and everything seems to be used as it is intended.

Creativeness - 1
I see nothing in this launcher that I have not seen in other launchers.

Quality of Build - 5
Although the launcher doesn't possess any new features, there should be no doubt that it is a beautiful build.

Function - 9
It almost functions as intended. If it were to get a better seal between the barrel and chamber, it would be good to go.

Idea: 12
You don't get too many piston hybrids, especially ones of this size which are portable and able to be fired from the hip. It'd help if I knew the cycle times, but I also think the break-barrel is a nice touch

Use of Materials: 5
Can't imagine what else you could do to make this better with the tools at hand. Also, cannon is very compact and clean.

Creativeness: 4
Although everything shown in this launcher has been done before, not all of it have been used on a single launcher in a hybrid. I think the builder was fairly creative in building a portable, hand-held hybrid with apparant fast cycling times.

Quality of build: 5
Everything seems top-notch, one heck of a launcher.

Function: 8
Everything seems to work well, there does appear to be a bad seal between breach and chamber and the possible fast cycling times seem to limit how many shots you can do in a certain time period as it appears to over-heat the chamber.

Score Chart
-Idea (20 pts max) 13 - Love the breakdown barrel to load and compact store. Also ventilated piston is a nice touch. O2 purge, gutsy but obviously very effective. Fuel meter in the support structure. Individually minimal innovation, but add up together in one package.
-Use of materials (5 pts max) 5
-Creativeness (10 pts max) 9 Unit as a whole unique and well conceived
-Quality of build (5 pts max) 5
-Function (10 pts max) 8 - I would like to have seen a little quicker and nicer barrel load and lockdown action. The thumb screw lock seemed a little out of place on an otherwise impressive entry. Also, there's some obvious leakage at the barrel breach as a very significant blast from that area is seen

-Idea (20 pts max) 13
Eh, not bad, but nothing great either. I've haven't seen that type of piston used in a hybrid, but I also don't see the benefits of it.

-Use of materials (5 pts max) 5
Everything works well together. I think the white parts would look better black, but I'm not going to count off for it

-Creativeness (10 pts max) 6
There is some creativity to it. This score could be higher if he explained how he implemented the o-rings into metal without any machine tools.

-Quality of build (5 pts max) 5
Clearly

-Function (10 pts max) 7
The blast at the breech is concerning. I wouldn't want to fire it with the gasses blasting out the side. The gun also needs to be set down and two hands used to close the barrel, looks a little awkward.

Idea: 16 has been done before but not exactly this way.


Use of materials: 5 just because he took time to match everything.


Creativeness: 8 two points off because break barrels have been around for some time all ready.


Quality of build: 5 it looks sweet!


Function: 5 he gets a big hit here from me because that leak at the breech is to much and will result in a unpredictable safety situation.

-Idea (20 pts max) - 9
-Use of materials (5 pts max) - 5
-Creativeness (10 pts max) - 7
-Quality of build (5 pts max) - 5
-Function (10 pts max) - 9

16
5 - Use of materials
8
5 - I envy the polish work. Possibly did it on the lathe as well. You can tell just from the segment edges in the reflection that he got a really uniform shine.
9

-Idea 14 not new, and O2 purge bad idea... If something goes wrong its bad for everyone. breech leaks
-Use of materials 5 nice materials, I'm glad there was no rhine stones.
-Creativeness 7
-Quality of build 5
-Function 7 is it supposed to shoot fire out of the breech?

Idea: 14
I don't remember seeing a piston quite like that, so good job there. The rest is pretty standard.

Use of Materials: 5
Top notch materials chosen here all around.

Creativeness: 7
Nice job making this launcher one tight little machine.

Quality of Build: 4
With the parts chosen, they were assembled very professionally. The electronics should have been housed in something though.

Function: 4
Here's where I'm gonna knock you down a bit. It looks GREAT, but I notice you left out a few things that could have made this launcher a LOT better: regulators and pushbutton/lever control valves for metering.

Nice job man!

Don't know if I get to vote but this would be mine:

Idea: 0 No new idea means no new idea

Use of materials: 9 it's a very good build

Creativity: 7. It takes creativity to get it all compacted and balanced out like that. It is way too industrial looking to get a 10.It's not art yet.Just clean and insustrial.

Quality of build:5 as good as it gets.Period.

Function: 9

Don't know you guys but this thing got my vote. Brilliant work.

-Idea: 14; neat, but not extremely new. Certain aspects of it's construction strike me as not being able to be done by the average spudder. I'm not a fan of oxygen unless used in a safe environment, but you seem to have it done ok.

-Use of materials: 5; Neat, perfect. I find it hard to believe this was done without serious machine tools but I'll give you the benefit of the doubt and say; "great job!"

-Creativeness: 7; The piston is new I believe, though I can't see it offering more performance than a burst disk, which could be implemented quite well with the breech load system.

-Quality of build: 5; Again, if you did this without a machine shop I'm impressed. It seems to all break down nicely.

-Function: 8.5; I have no doubts it works exactly as intended.

Idea: 5 - Not enough of an 'idea'

Use of materials: 5 - But common, there HAD to have been some machining done...

Creativeness: 4 - ^^

Quality of build: 5 - Can't deny its well made.

Function: 8 - Works fine.

BIG EDIT: After some clarification with Moonbogg, I now understand that it was not built using machining facilities.

I apologise to Moonbogg.

But mate you should show som of the processes involved in this finish! You are a master craftsman.

Very clean build, if not perfectly implemented yet. I'd really like to see more details on that valve after the votes are all in, and ask the owner how those burns on his arms feel. Unfortunately, those little oxygen tanks run out quickly, and are very expensive.

Mostly well built and effective, but a single screw to hold the breach closed seems rather unsafe.The only time I saw that much leakage out the breach of a launcher was followed by half an hour spent gathering up the barrel