Making a round counter (a-la pulse rifle)

[Im going space]

Right, so im very much considering making my UAR a battle rifle (halo 4 version) bodykit or similar, which obviously has a round counter in it. Now how would you make this? As id probably take a dig at modifying VN Midcaps to use in it. Im not after accuracy, only that its on 0 relatively near the end of the mag and resets to 36(?) when reloaded.

 

I get the basic idea of some sort of switch on one of the triggers and one in the magwell to reset?

Im fairly competent with electronics, so can do most things, im just after advice on how to go about it.

[DarkLite]

IIRC there was a chap who made a NERF longshot conversion on these forums - using a JG M4 inside with a LED round counter.

 

The county bit was actuated by a microswitch in the back of the gearbox which was hit by the piston.

[Im going space]

cheers DL, thinking of similar, i could obviously time how long it takes to empty a mag (140/30 = 4.66..) and go on that, but i use semi quite a lot too, which would mess it up. again, it doesn't have to be accurate, its only for show, but 0 on empty would be awesome.

[Wild_XIII]

I've thought about this a bit myself before. The idea I thought up involved using light gates like a chrono, but a small switch pushed by something like the piston sounds much easier to work in. I also thought about having another small button placed in the mag well, so that when you put in a fresh mag it would reset the counter by pushing a reset button. I'm incredibly rusty on my electronics as it's been a while since my college course though so I wouldn't know what sort of things I'd need to use.

[Im going space]

ive got an idea of what i can do with switches and whatnot, its the microchip itself that'd need work. could be interesting.

looking at the gun itself, there isnt a lot of work really, as if i take the upper off, the barrel is exposed.

 

only problem is going to be getting another one for less than the retail of £200

[DarkLite]

Odd you should say that. Give me a PM, I have a friend who might be getting shot of a DE one.

[Inari]

From the image you've shown a FAMAS would look to be a better base gun than the UAR

[Im going space]

The majority of the famas is just the wrong size though, and i prefer the V3 over the V1.

There isnt much work really, only in the detail really. I just dont want to be chopping up the only body i have.

[renegadecow]

How about a mic like on auto-wind mags? No switches to wear down, uses less energy than a light gate and you can put it pretty much anywhere without having to go into the gearbox or barrel.

[Im going space]

Fair point RC. Would still be difficult like that with pyro, and getting it to allow 4 BBs per round on the counter.

I think that light gate may be the most reliable option. (Can they run on 7.4v lipos? As im going to need to swap to fit one in the stock)

[Im going space]

With that i *think* its quite simple, a light gate connected to a counter of some sort that outputs once for every four inputs, to a two digit LED counter & decoder with a push to break reset switch in the magwell?

[Stuey]

I think a simple counter IC triggered by a light gate that shines either through your hop unit (like the Madbull tracer, to count BBs) or through your gearbox shell (to count piston cycles), which could feed a pair of those 7-segment LED displays to show number of rounds. The whole thing could be powered by your AEG battery via a suitable voltage regulator. The trick would be finding the right counter IC I think, I'm not really sure what's out there.

[Im going space]

Pretty much what im getting at, but MAG VN mids (what i intend to use for the mags) are 130 cap, so ill have to try count 108bbs and have it count down every 3 shots. As i dont want to limit myself to 36 round mags.

I might get on to my old school, see if theyll let me program a chip.

Edit: (counting 108bbs isnt an issue, just go on one count on the 7segments for 3 bbs)

[Im going space]

right, ive forgone the whole 'Numbers on 0 when mag empty' and gone the basic route, found a copy of circuit wizard from way back when i was in school, so hopefully they still use it... there won't be much of an update this month as im skint though.