Electronic gun QB 78/79 based
Very early stages of a project gun - now almost finished !
The gun is working very reliably shooting a very consistant 11.5 Ft
This was a bit of a long term project, the idea to build an
electronically triggered gun.
some of the steps are detailed below.
Benefits of the system
The trigger is a micro switch so no real pull and very consistant as
it is not holding a spring and hammer.
The gun is very economical on air, this I think is because when the
hammer is fired forward it strike the valve the valve will bounce
the hammer back - but as there is no spring in this gun to drive the
hammer there is no bounce back I need to sort some measurments out
to work out just how much air per shot we are saving - I will
probably go to a smaller cylinder as this one is good for 100's of
The gun has a choke BSA barrel so is very accurate
The Gun is triggered by a MOFET so almost no current through the
micro switch the MOSFET takes the current from the charge from the
The cycle time is a couple of seconds - to charge the capacitor -
power is set by altering the voltage on the capacitor.
The bolt is extremly light as no spring needs to be compressed.
First - make a hammer system to replace the QB hammer and spring,
some guess work really and the ability to easily adjust the weight.
I have some more ideas but will have to start on another gun as my
sone loves this one so much now !! I have a Chuntsman which may well
be a better choice as the bottom tube is bigger and ideally the
solenoid would be inside the pressure tube anyway - learned a lot on
this project !
Source a suitable solenoid and figure out how this can be linked to
the hammer - also must be adjustable
Build a test rig - we need a power supply - some capacitence
The current test bed - the system now fires and is reliable