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Just an FYI there was a post on reddit asking how to do a BB counter with Arduino. I pointed him to this thread. Hopefully you find some time to work on it some more, this has by far been my favorite project. I am still slowly working on my lasertag build. I have hit snags with timer conflicts when using the Arduino libraries but that is to be expected.

This new living arrangement is killing my creative drive. There's nowhere that I can safely work with an airsoft gun.
I have the module sitting next to me, in a box, 6 feet away. The minute I can pick it up again, I'm going after it. In the meantime, anyone that wants to see the work so far, let me know.

Definitely keep going with the lasertag project. That, I want to play with.
Hello there, I am looking at creating an ammo counter for my airsoft gun. I've done some searching online for these, and there are several ways to going about it, but I would like some advice from you guys as to which route would be most feasible.

“A swords never kills anybody; it is a tool in the killer's hand.”
Lucius Annaeus Seneca
Last edited by mrfriango on Tue Apr 16, 2013 6:46 am, edited 2 times in total.
This system worked pretty well. For actual BB counting, it was overkill (I think).
This system could measure the electrical usage of the gearbox and graph it out. This system could definitely count the number of times the gearbox cycled (How many shots the gearbox had put out). The intent was to put a series of photosensors in a muzzle break device/barrel shroud to detect the passage of the BB and use that as a built in chronograph. It would have been a very accurate actual shot counter as well.

I had to shelve the project because I moved.
I may be getting a new job, so the project may be getting resurrected. However, it's a completely open source project. If anyone wants details, code, pictures, they're free to use them as long as they're doing good things and willing to share in return.
By ksw9293
I stumbled across this thread about a month ago while I was in the middle of the engineering of my airsoft automation project. I put together a multi-function system that uses a photo interrupter for shot detection and runs on a Pro Micro (5V version). I'm writing up the process here: . Here's a shot of the operator interface:

The boards are up on OSH Park and I'll have the schematics up pretty soon. I'm still working on software but if anyone's interested I can share what I've got so far.
[EDIT: Fixed picture...too large]
Last edited by ksw9293 on Thu Jun 19, 2014 8:29 pm, edited 1 time in total.
Gorgeous write up. I just picked up a 3D printer myself, and I'm getting motivated looking at your work.
I'm really interested in Mac's question about the photo interrupter. I never got reliable counting out of my system (I used the exact same photo-interrupter you did. Well, one of several).

How is it in the field? I was really working towards a similar mounting system for my display. Pretty cool to see the convergence of design.

Nice work!
StaticDet5 wrote: Pretty cool to see the convergence of design.
Interesting isn't it ! :mrgreen:

I still think monitoring the current might be a good way to determine gearbox health. I swear that "we" could see indication of the 1'st GB going bad before it died on you. And still my opinion that a switch in the GB is the best way to get GB cycle info, if not the actual BBs shot.

Out of curiosity ... what 3D printers do you (all) have ? When I recover from having to pay to rebuild my supercharger, I'm thinking of getting one (XYZ da Vinci), more for the LOLs than any driving need.
By ksw9293
Mee_n_mac: No, no issues with double-detection. I've tested the system by firing a mag in full-auto into a BB trap and counting the captured BBs. So far, the display matches what I shoot.

StaticDet5: I've had it out once all day so far but lots of backyard testing before. I put a little more than 2000 rounds through it in 6 matches over the course of that day before my battery died. It was a useful test that pointed out some problems in the code.

One map is semi-only and the trigger response was good but I find that I need to look into my code to tighten up the response time between shot-detection and motor braking.
There's another field that's a CQB but bigger and I found that 4-round burst was a good way of providing supporting fire at point targets without wasting mags. It also helps people call their hits. This is where the counter comes into the fore because it helped me be aware of how much shooting I could do and prompted mag changes before I got involved in a push or defense.

There's still a lot of work to do.

Regarding 3D printers, I'm using an Afinia Cube (or is it a Cube 2?) and black ABS. It's only got a 6"x6"x6" print area so some parts, like the replacement top rail and display housing, are printed as assembly parts. I've had no trouble with the printer yet. It just works.

I'm still working on getting video of the system to post on the project blog.
I bought a RepRap Mendel Tricolour last month. I've broken it several times already and fixed it. I've identified a couple of improvements to it that I'm going to be able to do myself, with no problem. For one of the fixes, I needed to print out improved parts, and was able to easily do it (RepRap prints them out of PLA plastic, which is fantastic. I wanted slightly more durable ABS plastic because it is a higher temp plastic. I melted one of mine).

I really haven't done anything productive with mine (though I'm printing my first contract piece tomorrow), but I'm a huge fan. I just ordered some medical grade nylon filament and a replacement hot end (I toasted the heating element on one of 'em, and I want to have extra spare parts).

The printers are for tinkerers. This isn't something that you're just going to pull out of the box and set up (yet). I don't know about MakerBot, but you won't catch me buying one of those... I'm really pissed at them. It took me two weeks, working before and after work, only one real weekend day, to get it up and running. I really, REALLY, took my time to make sure things were right, tight, and level. In return, the machine was printing usable parts after my third print (I had a nozzle setting wrong).

I really recommend the kit that I got from RepRapPro. The kit comes with spare parts (you're going to need some of them. You may need some washers for shimming), and is pretty well laid out. It comes with all of the things that you should be thinking about: Heated bed, full length bowden tubes, multiple print heads, supports two different materials out of the box, open source everything (including parts), and a pretty good community online.

The big thing is to have patience with the build process. It will really help you if you can appreciate the journey to build the printer, and understand that the assembled printer is not the destination. You're going to be tweaking this thing continually, not because it's falling apart, but because you're going to see little things that can be made better. I'm already planning my next printer build for a new business idea that I have. I'll be able to take this printer and apply it directly to my bigger printer. I'm pretty sure I'm going to be able to use the exact same software.

Back to the AEG Computer... I completely agree with you on the current monitoring, but... a completed, working build is the real measure of success. Ksw9293 got his build done (my hat is off to you). With some of the things that I've learned, I may try tackling this again. I think our approach was really good, I just didn't have the mad skills with Arduino programming that is needed here. I wish I could do it in Python (got one of my libraries published in a recent book! Woohoo!).

This project started out with me wanting to make a highly configurable gas powered airsoft gun. That AS-50 gun looks pretty cool (I checked the HaD link, not the actual site. Stuck at work again).

Ksw9293, you're not in the Northern Virginia Area, are you?
By ksw9293
I'm in the eastern San Gabriel area of Los Angeles county.

There's no reason current monitoring can't work. The half-bridge driver I'm using might low-pass filter the current sense output, causing my issue. Believe me, I started out wanting to use dV or dI detection but the power section I'm using seems to smooth out those signals.

Instead of drilling a barrel I'm now looking at printing up a hop-up chamber with provisions for IR detection parts. That's going to be a tricky CAD session. In the end, positive BB detection is the only way to go, IMHO. With it I can also detect misfeed conditions, something gearbox monitoring could never do.
ksw9293 wrote:Instead of drilling a barrel I'm now looking at printing up a hop-up chamber with provisions for IR detection parts.
For that matter, and if you're willing to go really custom, is there any reason for a metal barrel ? Why not a clear Lucite (or like) tube, drilled out to a precision diameter ? Now you can look through the barrel and build feed detection and a chronograph into it ? It's not like the barrel has to handle the temps and pressures of a real firearm.
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