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Hybrid Spudgun

A hybrid potato gun is a mixture between the combustion and a pneumatic variety.  Simply put, you add compressed air, and extra fuel to the chamber before ignition.  The pressure is held in the chamber via a burst disk or burst diaphragm.  There are also hybrids that utilize valves, much like a pneumatic.  My hybrid spudgun uses the burst disk method.  I must warn anyone attempting to create a hybrid, that they create extreme power, pressures and heat.  Sch40 launchers have been made, but I cannot stress the dangers of this enough.  A sch80 chamber is the bare minimum you should attempt a hybrid with.  Should you attempt a hybrid?  If you are absolutely confident in your skill levels, in other words, both your spudgun knowledge and your construction techniques, you might attempt one.  But... honestly, not to sound like an elitist or anything, a hybrid should not be attempted unless you have an extremely vast amount of spudgun experience.  This means both pneumatics and hybrids, fuel meters... etc.  I had built probably 20 spudguns before attempting a hybrid, and have done many years of research.  They really are stepping up to the proverbial "next level."  If you mess up on a combustion or a pneumatic, you are out a few dollars.  If you mess up on a hybrid, you are dead.

This page is currently under construction, more info to come soon

Hybrid ignition system 

spark gaps: info soon

fuel: info soon

fuel/pressure relations and a chart: 

Fuel Charge Pressure (In PSI)
1x 0 (normal combustion firing)
2x 14.7
3x 29.4
4x 44.1
5x 58.8
6x 73.5
7x 88.2
8x 102.9

info soon

hyb_cam.jpg (70102 bytes)  hyb_cam2.jpg (89384 bytes)

hyb_leftview.jpg (234412 bytes)  hyb_leftview2.jpg (255397 bytes)

hyb_manifold_front.jpg (122032 bytes)    hyb_manifold_left.jpg (109688 bytes)

hyb_manifold_right.jpg (163569 bytes)  hyb_manifold_right3.jpg (148895 bytes)

hyb_backview.jpg (176395 bytes)    his2.jpg (181994 bytes)

A = 400psi pressure gauge for measuring peak pressure
B = Homemade Tee, machined from solid PVC stock
C = Air Compressor Drain Valve - for releasing peak reading
D = 1/4" In-line Check Valve (from mcmaster)
E = Homemade Manifold, machined from solid PVC stock
F = 1/4" male quick connect X 1/4" FPT
G = Schrader valve - for portable propane meter and portable filling
H = 1/4" street elbow
I = 1/4" ball valve (male x female) - for protecting gauge "K" from shock
J = 1/4" to 1/8" threaded bushing
K = 0-200psi pressure gauge - for measuring compressed air charge

test plug that doesn't work                                   flat pvc                                           oil jug plastic

16 layers of aluminum foil


navigation may be malfunctioning... fix to come soon.