Hi guys, I'd like to pick your collective brains on a project a couple of us are currently working on - making the ASG Sten a bit more realisticuser friendly.
The current area we are looking at is trying to fit a safety and a semi-auto mode. We know that the Sten uses a version 7 gearbox with modified motor cradle and no safetyselector mechanisms. We did have a look at retrofitting these but they are simply too bulky to fit within the gun - plus they are very complex and fiddly.
Our current line of thought is either to use a programmable mosfet to give a delay after the first shot, or use two trigger circuits (one with a semi - only mosfet and one with a normal mosfet). I quite like the second idea, but the prices start getting a bit steep! As for the safety we're just thinking of a concealed cut off switch somewhere in the circuit.
Can anyone recommend us some Mosfets that would be suitable for this? Or any other ideas are always welcome 
most reasonably priced is the King Kong burst wizard , can be adjusted to single then 1/4 second delay to full auto, airsoft world has them at £35 , i have one and its over a year old with out a fault , you can either have it as a plug n play or hard wire it in to get a larger option of functions .then next step up from that would be a gate merf II at about £55 or at about £70-80 for a really funky one.the king kong will do what you need at a good price , people are put off by the plug and play option as it has sluggish response but when hard wired it's a good option without the sluggishness.
armoury
m1a1 Thompson,sten mk2,mp40,stg44,sterling,mk2 bren gun,lee Enfield no4 mk1,Mauser Kar98, Walther ppk,smith and Weston m10 and Mauser m712
Give me a big enough hammer and a place to stand and I could fix the world.
i'll kill a man in a fair fight or if i think he's going to start a fair fight or over a woman or.......
a problem shared is a problem halved ,but an advantage shared is no advantage at all
if a job's not worth doing then its certainly not worth doing well
Thanks for the reply mate I did look at the King Kong- I was just a little put off by the way it does single to auto transition (just puts in a delay). I have a bit of a habit of keeping my figure on the trigger too long, and don't want to end up going full auto on some poor bugger at close range by accident. Intentionally is fine 
I may be being unrealistic, but I ideally want a switchable semi-auto to auto mode (thus two circuits). Unless there's a dirt cheap semi-auto only mosfet out there I guess I'll either have to fork out or put up 
the king kong can be locked to semi but as you said you would need two fet's however the second fet can be a simple one like a gate gds4004 , i have one of those as well , only £20 and rock solid , all you need is a way to switch the triggering wire between fet's and there's plenty of space behind the gearbox in the main tube .
my own sten has the complete ver7 gearbox , i took the view that if the trigger box had to be wider it was a price i'd pay , i used the cocking handle to select three positions by pulling on the plastic bar on the back of the ver7 box that operates the selection and pressing a micro switch for safety .but it comes at a cosmetic cost.
armoury
m1a1 Thompson,sten mk2,mp40,stg44,sterling,mk2 bren gun,lee Enfield no4 mk1,Mauser Kar98, Walther ppk,smith and Weston m10 and Mauser m712
Give me a big enough hammer and a place to stand and I could fix the world.
i'll kill a man in a fair fight or if i think he's going to start a fair fight or over a woman or.......
a problem shared is a problem halved ,but an advantage shared is no advantage at all
if a job's not worth doing then its certainly not worth doing well