Copperhead Pocket Launcher
Posted: Mon Sep 21, 2009 11:31 am
Several designs of mine were morphed into one for the Innovations contest but it wasn't completed in time and it didn't enter.
Thought you'd like to see some pictures anyway
Couple of handfuls of polymorph...
...plus some magic powder...
...and after 10 minutes in the microwave on full, plus extremely painful kneading of hot plastic...
This shall be the entire control system of the cannon, everything is standard except the Tee that Will machined for me:
Slapped on a bit of the old molten plastic to give it a bit of body...
Did I mention it's painful to work this stuff? It's workable above 60 degrees, preferably higher, bare hands are the best way but ouch.
Only took four hours.
More pictures will be forthcoming later
A sneak preview was shown so if you did see and understand please don't spoil the workings, thankyou
Compiled from the rest of the thread below:
Here's a picture of the pipe on the launcher and the machined Tee before I clamp it down with the compression fitting and the JFC:
The olive was secured first using JFC.
The pipe is 28mm copper with ~26mm ID x 600mm long
The pressure limit I'm setting is up to 300psi
And the projectile looks a little something like this:
Projectile is 25mm 16 BAR PVC x 570mm long before the nose. Clocks in at ~150g.
More closely at the pointy end:
The moulded polymorph nose has replaceable tips. The polymorph was blended with wax to allow self-lubricating of the screw threads. Also a steel nut in there to assist.
This is the entire launcher:
- The projectile is inserted into the launch (this is why it's not a cannon) tube, the replaceable tip is now a pointed spade bit which screws in.
- The compression fitting is then used to clamp a burst disk in place after the projectile, sealing it in. Unlike unions this clamp deforms the disk to hold it.
- Air is pumped in through the fill/pilot of the QEV, fills the space between the projectile tip and burst disk and just as importantly, seeps around the projectile to fill the hollow tail with compressed gas.
- On firing the QEV vents the space between the projectile tip and the burst disk.
- The projectile is slammed forward by the trapped compressed gas in its hollow tail and with the assistance of the puncturing bit, smashes through the burst disk and ejects from the launch tube.
And that is the Copperhead Pocket Launcher
Thought you'd like to see some pictures anyway
Couple of handfuls of polymorph...
...plus some magic powder...
...and after 10 minutes in the microwave on full, plus extremely painful kneading of hot plastic...
This shall be the entire control system of the cannon, everything is standard except the Tee that Will machined for me:
Slapped on a bit of the old molten plastic to give it a bit of body...
Did I mention it's painful to work this stuff? It's workable above 60 degrees, preferably higher, bare hands are the best way but ouch.
Only took four hours.
More pictures will be forthcoming later
A sneak preview was shown so if you did see and understand please don't spoil the workings, thankyou
Compiled from the rest of the thread below:
Here's a picture of the pipe on the launcher and the machined Tee before I clamp it down with the compression fitting and the JFC:
The olive was secured first using JFC.
The pipe is 28mm copper with ~26mm ID x 600mm long
The pressure limit I'm setting is up to 300psi
And the projectile looks a little something like this:
Projectile is 25mm 16 BAR PVC x 570mm long before the nose. Clocks in at ~150g.
More closely at the pointy end:
The moulded polymorph nose has replaceable tips. The polymorph was blended with wax to allow self-lubricating of the screw threads. Also a steel nut in there to assist.
This is the entire launcher:
- The projectile is inserted into the launch (this is why it's not a cannon) tube, the replaceable tip is now a pointed spade bit which screws in.
- The compression fitting is then used to clamp a burst disk in place after the projectile, sealing it in. Unlike unions this clamp deforms the disk to hold it.
- Air is pumped in through the fill/pilot of the QEV, fills the space between the projectile tip and burst disk and just as importantly, seeps around the projectile to fill the hollow tail with compressed gas.
- On firing the QEV vents the space between the projectile tip and the burst disk.
- The projectile is slammed forward by the trapped compressed gas in its hollow tail and with the assistance of the puncturing bit, smashes through the burst disk and ejects from the launch tube.
And that is the Copperhead Pocket Launcher
