SpudFiles

I'm so glad I found this thread! First and foremost, thank you highvoltagefeathers for sharing your experiences with this build. I actually saw your YouTube video first, eventually found my way here after researching "hail cannon", and then realized that you were one and the same person.

Anyway, I've been looking into higher-powered vortex cannons after messing around with one of those airzookas and thinking about ways I could increase the power/range of one, while also decreasing overall size. So herein lies my questions (to whomever can answer):

1. Could this hail cannon-like design be scaled down even further? For example, could I use a cone that has a 2" major diameter, .5" minor diameter, and is 10" in length? If so, how about one step further (1"/.25"/5")?

2. Would a 3/4" QEV alone be enough to produce the necessary flow to create a vortex ring in a miniature cannon as described above, or would it need to work in conjunction with something else (like a piston valve)?

In short, I am trying to keep this design as simple, small, and "plug-n-play" as possible. I want to minimize what custom fabrication is required even if it mean spending a little more here and there.

So here's a rough mockup of the design I'm thinking about:



Because these vortex cannons are high pressure/low volume, I figured why not make it semi-auto? A little bit of research turned up the qev-to-sv semi-auto design (youtube demo here). The configurations of the primary and secondary air tanks are undetermined at this point -- right now this cannon would be just under 20" long, so to keep it small I might get creative with the main tank and turn it into a chainsaw-style handle that doubles back over the valves. The cone itself will need to be custom fabricated, which I'll have 3D printed at Shapeways (considering it won't really need to be pressure rated).

shiddymunkie wrote:The cone itself will need to be custom fabricated, which I'll have 3D printed at Shapeways (considering it won't really need to be pressure rated).

Make sure it's at least 1/4" thick, don't underestimate the shock that a blast of air from a fast valve can give.

Do you think it needs to be 1/4" thick throughout, or just around the nozzle?

shiddymunkie wrote:Do you think it needs to be 1/4" thick throughout, or just around the nozzle?

I would taper from 1/4" at the valve to 1/8" at the end.

Here's the first rendition. It was designed a little differently than outlined in my first diagram. This cone is meant to fit inside of the 1" opening of a 1" x 3/4" reducing male adapter, which would then connect to the QEV.

Wireframe


Solid


Bottom


Aside from the small change in how the cone barrel will attached to the QEV, I also decided to go with a 3/4 slide valve with an integrated male adapter to optimize performance (and to simplify the build a bit). Both the 3/4" QEV and 3/4" slide valve have been ordered and should arrive sometime in the next few days. :bounce:

You deserved your own topic for this project!

I uploaded the cone today at Shapeways (can be viewed/downloaded here). It looks like it's going to be quite a bit more expensive than I thought it was going to be...but the way I see it, I could spend much more (in both materials and "hourly wages" for my time/effort) messing around with alternative ways to make this cone, and still end up with something that doesn't function or look as nice as this will. Ask me how I know this :blackeye:

Oh, I also received the 3/4" slide valve today -- this thing is big. I mean, I knew what the dimensions were before I bought it, but it takes holding it in your hand to really appreciate the scale lol

3/4" QEV arrived today

Wow... a 1/4" slide valve would have been sufficient to pilot the valve!

but the way I see it, I could spend much more (in both materials and "hourly wages" for my time/effort) messing around with alternative ways to make this cone, and still end up with something that doesn't function or look as nice as this will.

A very mature view, most people don't realize this until it's too late

jackssmirkingrevenge wrote:Wow... a 1/4" slide valve would have been sufficient to pilot the valve!

You know, this thought crossed my mind (after ordering the 3/4" slide, of course). Can I expect any performance improvement by using this bigger slide valve, or would any difference be negligible since it's only piloting the QEV?

jackssmirkingrevenge wrote:A very mature view, most people don't realize this until it's too late

Yeah, I've had to learn the hard way more than a few times before it really sank in.

shiddymunkie wrote:Can I expect any performance improvement by using this bigger slide valve, or would any difference be negligible since it's only piloting the QEV?

Theoretically, it will pilot faster and you will have slightly better performance, assuming you can open it at the same speed - which, because it has more friction and mass, you won't - in practice, you should not notice any difference between this and a 1/4" valve.

Yeah, I've had to learn the hard way more than a few times before it really sank in.

Alas, the hard way is usually the only way.

jackssmirkingrevenge wrote:
Theoretically, it will pilot faster and you will have slightly better performance, assuming you can open it at the same speed - which, because it has more friction and mass, you won't - in practice, you should not notice any difference between this and a 1/4" valve.

So long as the size isn't hurting performance because of the added mass/friction. On a side note, the cone/barrel has been ordered...but it'll probably be two or so weeks before that comes in.

shiddymunkie wrote:So long as the size isn't hurting performance because of the added mass/friction. On a side note, the cone/barrel has been ordered...but it'll probably be two or so weeks before that comes in.

In the meantime, why not have some fun and shoot some projectiles like spudguns are supposed to

Shittymonkey -

Just out of curiosity - what is shapeways charging you for that part? What manufacturing process and material did you request?

Not trying to steal business from them - just interested in the pricing mechanism they use!