Hi folks!

I still haven't completed my Pulse Rifle and want to finally finish it this year. That means fitting and repainting the shrouds, but also installing the ammo counter. The counter is ready and working, but I can't seem to find a solution regarding the wiring and the switches.
Since I am using a WE GBBR M1A1 which can cycle the bolt, I will need three switches:

• Magazine
• Trigger
• Bolt

Magazine
Now, the switch to detect whether the magazine is inserted seems to be the easiest of the three. I would most likely simply use a lever type micro switch or a roller lever micro switch.
I'm looking for input what switch you used and how you installed it (i.e. did you just use hot glue to position the lever or something more elaborate?).
I also seem to remember that someone used a switch with magnets? That could be interesting as well, although it may be more complex since the magazine would have to include a magnet (as far as I remember).


Trigger
Now this is where things get more complicated. It seems that the WE GBBR Thompson functions like a real M1A1, meaning it has a rocker in the lower receiver that could be used to actuate a switch. However, I am not sure if the parts are identical to the real steel M1A1 or if they differ in size and/or function. The problem is that it seems that all of the parts are supposed to be movable (i.e. several parts move when the magazine is inserted, when the levers on the side are used or when the trigger is pulled), so I don't know how and where to even mount the switch.

There are a few images here showing the wiring of the old SD Studios Pulse Rifle, but the images are too small to make out much detail, especially on how they mounted the switch. It shows that they cut a channel into the front of the lower receiver to lead the cables out of the lower to the counter, which seems interesting. I didn't think about that at first, but that seems to be the only way to lead the cables out, any other way and the cables would either get in the way of the magazine or the bolt.


Bolt
Now this one really has me stumped. I guess it might be possible to use a lever type micro switch again if I could somwehow position it in the lower receiver. I do have a couple of really small lever switches that could fit. Still, there's the problem on how to mount the switches in the small space of ever moving parts. Or maybe a button type switch at the rear of the receiver that registers when the bolt is pulled back? That would make it necessary to get the cables all the way back though. A push button at the front doesn't seem feasible.
It seems someone did in fact wire the bolt of their WE GBBR Thompson somehow, unfortunately I haven't heard back from them...


So, anyone who has their Pulse Rifle wired up, I would be very grateful if you could give me some pointers on how you did it. Maybe someone has an SD Pulse Rifle and could snap a better image of the lower receiver? Everything could be helpful!

Cheers and thanks in advance!
Roman

When adding my set-up, I faced much the same issues.
Tested a few different switch types and layout ideas, before it fell into place.
Mine is a older matsu, retrofitted, so not sure how helpful, but here it is, during install.

Thanks for the input!
Neat to see the mag with a reed switch! I might still use a lever type microswitch for ease of use and since they're so small though.

Alright, this thread by Hicks27 has a good starting point for a trigger switch. It is also based on the original SD Studios Pulse Rifle wiring. I also saw that it might be possible to get a micro tactile button below the front of the trigger (right next to the trigger spring).

Still looking for a way to wire up the bolt though. I could put a micro tactile switch into the "buffer" at the rear, so that the bolt hits it. My fear is that the blowback will not bring the steel bolt all the way back (especially after the first few powerful shots, when the gas pressure lowers a bit) and the counter will not actuate. Also, I'd have to route the wires through the lower receiver somehow, meaning I'd have to either carve a long channel into the steel or drill a hole into the lower or upper receiver, which I'd like to avoid.

It might be possible to put a switch just a bit forward of the bolt so that it pushes the button when it is in its forward position. Very little space there though...

Cheers!
Roman

What will the wiring to the bolt function as? It will count down the display? (Rather than a button on the trigger)

I have set up my counter for two modes:
1. "Display mode", where the counter counts down when the trigger is pulled, as long as it is pulled (i.e. "full auto"), and
2. "GBBR mode", where the counter counts down whenever the bolt switch is triggered, no matter whether it is a single shot or full auto.

I did this because it is pretty much impossible to sync up the counter with the blowback action (depending on the amount of gas, temperature, etc.), but I still want the counter to work when I'm playing with my Pulse Rifle at home while watching Aliens (i.e. without gas/ammo).

My thought for the bolt would be keep it none contact, a magnet fixed to the bolt and a reed switch in the right place?

To cater for bolt travel variability you could use a reed with normal closed and put it at the front so the magnet holds open circuit when bolt closed and closes/triggers the circuit when bolt goes back?

_________________
Alan T. Alien
1st Lt Smith, SA "Sidewinder"
A13/TQ1.4.19720EX CMA
Founder of UKCM 13th Regt. 1st Batt. Freebooters
Founder of Special Armaments Section (Heavy Weapons)
"People don't understand. people like me"

Hi there Sidewinder!

Great suggestions, several of them I have already implemented in my prototype solution which I will post soon.
Stay tuned!

Cheers!
Roman