Tuesday, December 9, 2014

LTX M41A Pulse Rifle: Part 1

In September of 2009, I set out to build my favorite Sci-Fi blaster of all time: the M41A Pulse Rifle from Aliens  (James Cameron, 1986).  This iconic bug-slugger has transcended it's initial appearance almost 30 years ago and has been featured in other Sci-Fi films, Video Games, and even had real-steel versions made for it's massive following.

When I started the project, I used a G&P Pulse Rifle Airsoft Conversion kit for an M1A1 Thompson Submachine gun.  I left it as a functional Airsoft rifle but, thanks to the unique design of the Pulse Rifle, I had plenty of space to drop in my own Laser Tag system.  At the time, the Omaha Laser Challenge Association (now the Midwest Laser Tag Association) was utilizing Laser Challenge-brand equipment for games, so the half Airsoft half Laser Tag M41A had Laser Challenge V2 internals mounted inside the vacant "Grenade Launcher" housing underneath the main barrel.  Much like a Nerf Longshot Front-Gun Integration, there was plenty of space for the lens arrangement, motherboard, speaker, and buttons for operating the Pulse Rifle's new Laser Tag feature.  

A 3-Pole Switch controlled which system was active at any given time.  The middle position turned the blaster off.  Forward would send power to the Laser Tag internals.  Backward would send power to the Airsoft motor.  It was simplistic and it worked quite well for quite awhile!

However, when our Laser Tag group made the switch from Laser Challenge to Lazer Tag (LTTO, LTX, LTAR), this blaster quickly became obsolete.  Many attempts were made over the years to install new systems based off of Arduino Development Boards to work with current equipment, but they were never really successful.  Though the project is officially half-a-decade old... there's still things I can do to make this work like I had originally hoped.

So now you're all caught up with this blaster's backstory and ready to see what's coming next, right?  This M41A Pulse Rifle will be running off of a Phoenix LTX laser tag board and will utilize the features of the unreleased RapidBlast attachment to mimic the high rate-of-fire that this icon of Sci-Fi is known for.  I know what you're going to say:  "Zook... how on earth are you going to use the RapidBlast if it was never released?"  That's were my friends at CTDYNE come in!  Take a read.
We had three PCB's for the RapidBlast manufactured. We assembled the first board and did the trouble shooting and refinements necessary to get it to work properly. This is the board you see in the images of the CSM I sent you.  The second one will be used in a build similar to the CSM, but without adjustable focal length and one off lens assembly. The second unit will go to Izzy as a thank you for all his hard work getting the design to a state where we were able to have the boards produced. The third board from this initial production run will end up in a housing just the same as the one going to Izzy. 
Not to worry though, now that we have the bugs worked out of the design, we are planning on having second production run of ten additional RapidBlast PCB's manufactured. We can provide a bare PCB and a pre-programmed processor chip with the parts list available at Izzy's Github site. I would certainly be willing to build a complete board for Bazookafied.
While I eagerly wait for CTDYNE to work on that, I've still got a long road ahead of the Pulse Rifle to get it LTX-ready.  A lot of testing, breaking, fixing, troubleshooting, and modification is ahead of me, but at least there are still bits and pieces of the previous attempts that can help.  Most notably, the work we did on fabricating areas to house the IR Sensors in the blaster will not have been in vain.  We will repurpose those to work with the LTX board at the core of this project.  I've never built an LTX or LTAR before without reusing the existing sensor dome, so I have a feeling that'll be an interesting experience working through the problems that will likely arise from that.  Still, it's the first step in a winter-long journey this blaster will have to take if I ever hope to have it running for Season 10 next summer!

Over the next several weeks, I'll be getting the Pulse Rifle operational again, which will likely have more in-game testing too to make sure that everything is working as it should.  It's important to not only make this blaster reliable and fun to use... but also that the sensor placement and design doesn't interfere with gameplay.  The last thing I want to do is build an awesome blaster that no-one can hit and then get everyone upset!  Updates on this first round will be coming soon!


  1. Awesome! Really excited to see where this project is going!

  2. Is that picture of you in the snow recent?

    1. No, that's from 2 years ago. It's the last time we used it with the Laser Challenge system in it, too.

  3. That is a great version of an iconic movie gun!