Lazer Tag Team Ops

Adapter to mount Red Dot style sight

Okay, so by now I guess we all know the stock sights on the LTTO Deluxe model -- how should I put this -- well, basically they stink. I won't go into why they are the way they are, suffice to say it wasn't planned that way. But circumstances conspired to make them the way they are, and now we're all stuck.

If we could only mount an off-the-shelf Scope or Red-Dot sight or even a better notch-and-post site along the top, we'd be a lot better off.

So I was thinking about this as I happened to be wandering through my local Wal-Mart the other day, and in the Paintball aisle of the Sporting Goods section I came across a cool red-dot style sight for only $8.99:

There are some minor problems to overcome, unfortunately. Chief amongst them is that the "Weaver" style Accessory Rails on the LTTO are NOT standard 7/8-inch Weaver Rails, and even if they were, this sight uses 3/8-inch rails. The LTTO's rails are more like 15/16-inch, making them too large for most off-the-shelf gear to be mounted on them, meaning a stock adapter is not likely to work. I have my suspicions that this was done to keep people from mounting off-the-shelf laser pointers on the rails, but I can't say for sure. A secondary problem is that the LCD housing requires quite a rise above the rail, rather more than would be typical for most applications, meaning it's going to be hard to find something to fit. And a minor problem is that the accessory rails are just a bit on the SHORT side, at least compared to what you'd expect to find normally. Again, this means off-the shelf solutions are not likely to work well.

I took the red-dot sight's rail clamps off, and found that there is an internal base that is just a hair under 1/2-inch wide running the length. Originally, I thought I might make an adapter that would clamp onto the LTTO rail and be about 3/4-inch wide at the top with a 1/2-inch slot milled down the middle, into which this base would fit and a pair of crosswise screws would hold the sight into the channel:

But the more I thought about it, the more I wanted to come up with an adapter that almost anyone could make with tools that most people would have access to -- not mills and lathes and such, just a table saw and a bandsaw or jigsaw/scrollsaw type of thing.

Then after some posting back-and-forth with ExitWound on the Lazer Tactical Action Games message board, I realised that by using only a 3/8-inch wide upright and cutting grooves on either side, I could eliminate the precise drilling for the screws going crosswise, which would have been tricky to get right without some very nice tools. That's a step in the right direction and it means the final design would have no undercuts, so it would be a really simple matter to make a mold from which dozens or hundreds could be made easily. So now I'm looking at something like:

The final bit of inspiration came when I realised that three thicknesses of 3/8-inch sheet, stacked on top of each other, is just enough to fit completely around the LTTO rail with 1/10-inch to spare on either side. That means the device can be spilt up into 3 parts, each very easy to make on a tablesaw:

Now we're talking! The two side peices are mirror-images, so can be cut in a single pass using a table saw, producing a notched strip twice as long as needed -- then just cut the strip in half and you have two identical peices. The grooves in the central upright piece can be nothced very easily by tilting your tablesaw blade to the 45-degree angle position, and just cutting a little groove with the corners of the saw blade tips.

The side peices can either be glued to the central piece (my choice, using Plastruct ABS/PVC cement, but standard model glue would do fine as well), but could just as easily be drilled and held in place with a couple of 1-3/8" #4-40 screws with nuts. I would NOT reccoment cyanoacrylate "super glue" as it has been my experience that it shatters too easily when used to glue smooth surfaces like plastic.

To make the side peices, I used the adjustable fence and square slider on our table saw to cut the slots along the lower edges into a much longer peice than needed, to give me a working grip. Once the slots were done, I cut the whole strip off and then cut lengths from that strip as needed.

The dimensions of the side pieces and their slots are as follows (length will depend on your design -- mine were 0.800" long each, so I made about 2-1/2 inches of it and then cut the two shorter peices from that):

So basically, I took a chunk of 3/8-inch ABS stock, about 2-1/2 inches wide and about a foot long, and squared it all up. I then lowered the table saw blade until it only poked up 0.175" from the table, and notched the end of the peice in for the first 0.265". I then raised the table saw blade up to 0.255" above the table, and VERY CAREFULLY cut a deeper slot beginning 0.090" in from the end and going the remaining width of the original 0.265" cut. With this done, I raised the blade to about 1/2" and cut the entire end off to a width of 0.600". This gave me a roughly 2-1/2" long strip of the cross-section shown, from which I cut two pieces that were 0.800" long.

Then from another chunk of the 3/8" stock, I cut the following peice (designed to fit up and around the LCD enclosure to the lower right, without interfering with the IR dome to the lower left):

I did find that it fit a bit loose once it was all glued together, but a peice of paper-thin PVC plasic snugged it right up. Eventually I need to add a set-screw to keep it all from falling off as I run around, but for now it looks like this:

email-id@comcast.net

Here's a .PDF file with the drawings and dimensions