Airsoft Canada - View Single Post

Magwell · May 20th, 2018, 00:30

Another Box Mag mod here..

I've been toying with the idea of some kind of self-contained tracer set up after testing my suppressor style tracer in 2017 on this MG. The tracer i have is a lower end unit and had a very hard time keeping pace with my ROF. Not to say that a higher end unit wouldn't be able to, but the added weight and length on the end of the barrel were not ideal.

So over the winter I started with some googling... and stumbled across an interesting website which detailed one way of adding UV LED's to a standard M4 hop up unit to turn it into a tracer. On the 249 models the hop up is small and the access to it is tight which got me thinking of other locations which might work well... And voila, box mag came to mind. So some more googling on that and it looks like some people have added UV lights inside the 'chamber' which houses the bbs en mass, but I didn't like this idea.. Firstly it only illuminates the BBS on top of the box mag, it uses up valuable space for ammo, and it would be semi-reliable at best. So i started thinking, and came up with the following...

1. References:
A: https://www.meetup.com/Puget-Sound-A...hread/48656383
B: http://scriptasylum.com/rc_speed/led.html
C: https://www.digikey.ca/en/resources/...or-code-4-band
D: https://www.bivar.com/portals/0/prod...3TZ-XXX-XX.pdf

2. I found myself on Digi-Key Electronics and ordered some 405nm/3.3v UV LED's. I ordered ten which came in at around $30 CAD, so far so good.

3. I have tons of wire and a large number of resistors from other projects kicking around, but these are pretty inexpensive to come by, $5-15 at the Source or online.

4. First, the 3mm LEDs needed to be 'cut down' to avoid blocking the BBs, so I took a dremel to the end and then polished it to make it nice and clear again.

5. Disassembled my box mag and pulled out the insert which feeds into the hop up. After eyeing it up and down, I decided to install four UV LEDs inside the channel right before the bb's enter the machine gun. I drilled two small holes to route the wires through for the right hand LED.

6. Each lead had to be soldered to some 20 awg wire.

7. I then ran the leads down into the box mag, soldered my resistor (after calculating the required resistance rating, and selecting the appropriate resistor), and soldered in a rectifier diode to make sure that the active brake did not harm the LEDs. With this set up, the LEDs are off until I pull the trigger, and will operate in tandem with the Gearbox and Box Mag motors.

The result is a nice purple hue coming from the tube.

And so far it looks like it will work great! There is a night game coming up next week, so I'll report back on how it performed. I'll add a small switch to toggle it on/off on the fly incase more stealth is needed and also hot-glue the LEDs in place to secure them.

Video: M249 Box Mag Tracer Test

May 20th, 2018, 00:30	#28
Magwell Trader rating Join Date: Sep 2012 Location: Edmonton, AB	Another Box Mag mod here.. I've been toying with the idea of some kind of self-contained tracer set up after testing my suppressor style tracer in 2017 on this MG. The tracer i have is a lower end unit and had a very hard time keeping pace with my ROF. Not to say that a higher end unit wouldn't be able to, but the added weight and length on the end of the barrel were not ideal. So over the winter I started with some googling... and stumbled across an interesting website which detailed one way of adding UV LED's to a standard M4 hop up unit to turn it into a tracer. On the 249 models the hop up is small and the access to it is tight which got me thinking of other locations which might work well... And voila, box mag came to mind. So some more googling on that and it looks like some people have added UV lights inside the 'chamber' which houses the bbs en mass, but I didn't like this idea.. Firstly it only illuminates the BBS on top of the box mag, it uses up valuable space for ammo, and it would be semi-reliable at best. So i started thinking, and came up with the following... 1. References: A: https://www.meetup.com/Puget-Sound-A...hread/48656383 B: http://scriptasylum.com/rc_speed/led.html C: https://www.digikey.ca/en/resources/...or-code-4-band D: https://www.bivar.com/portals/0/prod...3TZ-XXX-XX.pdf 2. I found myself on Digi-Key Electronics and ordered some 405nm/3.3v UV LED's. I ordered ten which came in at around $30 CAD, so far so good. 3. I have tons of wire and a large number of resistors from other projects kicking around, but these are pretty inexpensive to come by, $5-15 at the Source or online. 4. First, the 3mm LEDs needed to be 'cut down' to avoid blocking the BBs, so I took a dremel to the end and then polished it to make it nice and clear again. 5. Disassembled my box mag and pulled out the insert which feeds into the hop up. After eyeing it up and down, I decided to install four UV LEDs inside the channel right before the bb's enter the machine gun. I drilled two small holes to route the wires through for the right hand LED. 6. Each lead had to be soldered to some 20 awg wire. 7. I then ran the leads down into the box mag, soldered my resistor (after calculating the required resistance rating, and selecting the appropriate resistor), and soldered in a rectifier diode to make sure that the active brake did not harm the LEDs. With this set up, the LEDs are off until I pull the trigger, and will operate in tandem with the Gearbox and Box Mag motors. The result is a nice purple hue coming from the tube. And so far it looks like it will work great! There is a night game coming up next week, so I'll report back on how it performed. I'll add a small switch to toggle it on/off on the fly incase more stealth is needed and also hot-glue the LEDs in place to secure them. Video: M249 Box Mag Tracer Test __________________ Last edited by Magwell; May 20th, 2018 at 00:53..