MIKE revisited

[VH_man]

Well, after the initial construction of MIKE, I got bored with the fact that it could only be fired from the hip. Also, i was getting tired of having to watch the BV trigger REALLY CLOSELY, because one knock on that crappy Ballvalve I had would result in an instantaneous firing.......... Aka BAD.

Also, MIKE had the problem of the nut on the back of the piston coming loose. I replaced the normal nut with a locknut and a lockwasher. It hasnt come off scince....

The most visible improvement in MIKE is the obvious addition of a 1/4 inch QEV as a pilot. It works EXTEMELY well, and I can pilot the cannon with a slight twist of the trigger Ballvalve.

I run it at around 400 PSI now, and I beleive that I have finally hit Transonic with a Marble (1000 FPS to 1200 FPS). The recoil is RIDDICULOUS and the damage is VERY satisfying. I will have a video of random stuff getting destroyed when I find the time.

Anyway, enough Talking, Picture Time:

The new Pilot Assembely. Notice the Piece to direct airflow away from the users Ear.....


A site I made out of VEX metal. Works great for what I do.


The new Trigger Assembely. Yes, there is no Pistol Grip. I can actually hold this gun quite ergonomically without a grip. I do need a better way of attaching the BV however, Servicing the piston is NOT fun.


Finally, the Revised Money Shit:

[ALIHISGREAT]

nice, although the BV still isn't very safe... maybe a second one with a small handle behind it to act as a safety valve?

but other than that its nice!... although i would put a bit of tube on the exhaust on the QEV to help with the noise (its what i have done on my copper coax)

oh and how does the sight work? and how long is the barrel?

[VH_man]

The Barrel is the same as on MIKE 1.0, its about 40 inches long.

I was thinking about mounting a 1/4 inch BV between the QEV and the copper tubing...... Hmm. I do have a spare one....

I did have a Muffler on the exhaust (one of the cool brass silvery thingies.... my friends dad makes machines with them in them) and it EXPLODED under the 400 PSI output pressure. I will get a new muffler eventually, becuase im getting tired of having my ears ring even after i have earplugs and earphones on.........

I might actually put a pistol grip on, i found an old drill that has a "hefty" grip, not to mention i need the motor for a robotics project. Ill post it if it works.

[starman]

Not bad although I too would do something else with the ball valve. The high pressure you are running may preclude you from using flexible hose as a pilot, but that copper pilot makes it more difficult to work with.

Make it to where you can't accidentally fire the BV by just laying the gun down.

[VH_man]

The problem is i want it to be ergonomic... ATM i can fire it from my shoulder without much trouble.

I think i might take your advice and do something different with the BV, like attach an electronic Pilot-Valve Piloter (hehe) and make the gun have a "feather" trigger....

To save money, however, Anyone know of a more flexible tubing I could use as the pilot? Right now im about to put a Union into the copper tubing so that i dont have to take off the bloody hose clamps.....

[SpudUke5]

i have always wondered what kind of copper tubing that people use to connect the pilot valve to the ball valve and how you guys attach to the QEV and the BV. So i would appreciate i if someone could point that out for me.

[VH_man]

Its called "flexible Copper tubing"

It comes in 500 foot rolls or 2 or 3 foot lengths. To attach the tubing to the gun, you use a compression fitting.

its that simple... And its really a Beeotch to work with. I only reccomend using it if you HAVE TO.

[ALIHISGREAT]

yeah, i have some 6mm copper tube for my coax with 6mm to 1/4" BSP (would be NPT for Americans) comp fittings

[POLAND_SPUD]

you can lower the level of sound by simply attaching a pressure hose or copper tubing to the exhaust port and have it go 'boom' away from your ear



I see that more and more people use small QEVs to pilot their guns....

IMO it's ok to do so but I don't get one thing - why do you build piston valves if you can get a 3/4" QEV for as little as 25 - 30 $ ? wouldn't it be cheaper to use a 3/4" QEV instead of having to spend about 10$ to build a homemade piston valve and then add a small QEV to help pilot it ?

I am not saying that homemade piston valves are not practical - they are great esspecially if you need a large valve ( 1" or bigger).. but normally if you can buy QEV it's cheaper and easier to use a QEV as a firing valve for small bore guns

[VH_man]

Its becuase my copper piston valve:
1. I built it. Its mine.
2. Its low Profile.

those are the reasons.

[POLAND_SPUD]

hey it wasn't reffering to your gun... I like it the way it looks now...

I've been thinking which option is cheaper that's all

[VH_man]

lol. sorry if that sounded harsh, it wasnt.

just stating what i feel about QEV's.

I totally agree though. the most powerful cannon ive ever built had a 3/4 in QEV as the main valve........ And the piston valve is definetly cheaper to a degree but its also far more prone to problems.

matter of preference i guess....

[ALIHISGREAT]

i agree with VH_man

its better than a QEV because you get the satisfaction out of making it.... wheras there is not much satisfaction in ordering a QEV off the internet

[POLAND_SPUD]

yeah building something on your own is fun...

but it's easier to build a piston valve if you use copper not malleable iron pipes and fittings...

I personally use the latter so a QEV is my valve of choice... toghether with threaded fittings it gives you a lot of freedom and customizability (did I spell it right ? ) you can try different designs, barrel/chamber sizes and lenghts...

well it seems It's just a matter of personal prefference and material availability

[Hotwired]

I did have a Muffler on the exhaust (one of the cool brass silvery thingies.... my friends dad makes machines with them in them) and it EXPLODED under the 400 PSI output pressure. I will get a new muffler eventually, becuase im getting tired of having my ears ring even after i have earplugs and earphones on...

I'd not feel too happy about overstressing commercial silencers to be honest, having a muffler made of tiny sintered bronze balls blow apart next to me did not make it onto my christmas wishlist.

Why not make your own?

I've got an expansion chamber for the pilot exhaust on my cannon which is the hollow grip of 22mm copper pipe (under all the plastic) and then there's a small 3-4mm hole in an endcap at the base (also under the plastic) that the expansion chamber vents from after that.

Something like that filled with steel wool should work perfectly and would be a less resilient material for a pilot blast of 400psi to smack into.

A grip probably wouldn't fit in there but just a bit of pipe at 90* wouldn't be too bad.

Its called "flexible Copper tubing"

And its really a Beeotch to work with. I only reccomend using it if you HAVE TO.

Ahhh I didn't think it was that bad

It IS a menace to bend with your hands and if you use hard tools on it that aren't the special bending ones you end up collapsing and pinching the tubing.

But still, if you take time with it and use padded stuff to bend it or best of all a real pipe bender it gives a nice sturdy result and won't swell in a slightly worrying way like plastic tubing when it gets pressurised.