I'm working on a rail mount rangefinder, and could use some input as I make progress.

[XOIIO]

Hi everyone, this is a project I kind of got stuck in my head, and chances are it's a one off thing just for me, but if there's interest it's also the sort of thing that might be fun to set up a kickstarter or something for so that people who are interested could get one, I really don't know what the impressions for you guys will be on this lol.

So, basically, I got it into my head that it would be pretty cool to have a rail mounted laser rangefinder for scouting stuff out. There is already one product out there, but it's pretty expensive, and while it's rated at a longer range, it doesn't fit what I want very well.

So, the basic idea is to have a rail mount range finder, but have it all fairly low profile, something that in theory wouldn't interfere with your sight picture if mounted directly in front of a scope.

I also wanted the display to be a separate section, again something low profile that could mount underneath the scope on the rail, that way a quick glance down would show the readout, and not be a really big target hanging off the side of your gun that would be easy to shoot out, or get caught in stuff like brush.


So, I poked around alibaba for quite a while and found quite a nice compact, 600m laser rangefinder module, pretty much the smallest that has a long range, and also wasn't crazy expensive for a sample unit as I could find.

I've got it here, so I made a model of a picatinny rail and the rangefinder unit and right now I'm just working on designing what the case would look like roughly as I don't have a super good picture of what it would be like in my mind.

I know that I will have a good thick piece of glass or lexan/margard in front of the rangefinder, because I want it to have built in protection from bb impacts, this is something that the other rail mount rangefinder doesn't have, and it would really, really suck to get it smashed out.


Anyhow, right now I'm trying to figure out if I want to go with a pretty slick, contoured sort of design, or something boxier, maybe a little angular or more like a PEQ box, I don't have a battery one to hand for a good sort of look at, but I also don't really want this to just be a PEQ box clone that has totally different functionality, I want it to be it's own sort of thing.

These are two super duper rough designs that I sketched out.



The angular one is really rough and that's probably why I'm not much of a fan of it, and it would also be harder to mount right by a scope without causing line of sight issues.


Another factor is that I think it might be good to add some sort of second functionality to this. In terms of if I was making it to sell this would just increase the price, but some sort of other functionality would be a nice to have.

I don't currently have a laser on my rifle, so I was thinking it might be cool to integrate one, it would fit nicely in the first smooth design, be centered on the rail if I wanted, and not super expensive, however I would also need to figure out how to make an adjustment mechanism that actually works, and doesn't lose it's position, something which I'm not quite sure how to do.

The laser would be red or green, and if you were a night vision guy the rangefinder uses an IR one so that's sort of built in functionality.

Another thing that could be good is a flashlight of some sort, however high power lights are quite large, and quite power hungry, as well as generating heat that needs to be handled. IR illuminators have the same sort of issues associated with them, and I see them on a lot of combo light laser boxes, and I mean it's cool to have but I know I can't afford night vision, so practical use seems fairly limited.

Something like a regular flashlight would basically require interchangeable batteries which is harder to do if you are making the thing out of plastic since you can't use the the case as a ground for one side of something like a cr123, so I'm leaning towards a built in LIPO battery, something like 800mah.

Oh yes, and the display will be OLED, and I'm thinking of adding a light sensor and gyroscope into this, so that basically when it was dark out the display would dim downa bunch, and with the rifle aimed down turn off and stop range finding so that the display and the IR laser weren't on for sneaking around. I haven't messed with the OLED I have much but I should be able to dim it.



So, for those who took the time to read this, and even moreso those that share their thoughts, I greatly appreciate it.

I'll mention again that this is probably just a one off project for me since it's practical uses in airsoft are probably pretty limited, so I'm not all gung ho to sell a bunch of these, but who knows maybe some of you guys will think it's kind of a nifty thing at least too.


edit: software stuff should be relatively easy to figure out once it's time, depending on features I want to add and whatnot, but they sent me the module without the actual wiring harness to connect to it, so I have to wait. I was going to do basic software first, but I guess now I'll work on the case lol. Probably going to be two or three weeks until I get the harness, if the module wasn't so tightly integrated I'd remove the connector to solder directly to it, but there are surface mount components on the opposite side that could fall off if jarred while using my hot air station, so better to wait.

[XOIIO]

Someone on reddit mentioned the Meyers MAWL as a design for an offset mount and I really quite like that, it could potentially get in the way of things like bolt handles I suppose, but I might whip up a rough design a little more like that.

Also, 600m isn't amazing for range I know, but modules with longer range are quite a lot larger and bulkier, as well as pricy, or have integrated optics with screens since they are meant for gold rangefinders. They also don't seem to have standard TTL outputs that are easy to get to so I ruled those out.

edit: It's also possible this will read past the 600m point, I don't know for sure until I can test it, it may be based on accuracy that the specified 600m for this one but they seem to have somewhat conflicting pages and multiple models that look the same as this, but have different range specs, so idk.

[XOIIO]

So, I ended up liking the downward offset a little more and spent some more time on the design. Still super early, but I think this is a good starting point and roughly what this half will look like in the end.

I didn't yet account for retaining glass or plastic to protect the rangefinder and possible laser, though to be honest I feel like the adjustment mechanism for the laser would be pretty bulky.

[XOIIO]

Not sure if I'm totally in love with the design, definitely helped giving it a quick blast of black paint, but it's nice and low profile, clears my spectredr and it's kill flash, so should clear a lot of other scopes pretty easily too and even some red dot sights, and of course it could be mounted on a sideways rail.

I was considering trying to make it something you could swap from side to side but that would add a fair bit of bulk, so I think if if it got in the way of the bolt handle having a mirrored design would be the way to go about it.

Still have to think about button placement and whatnot, was thinking maybe on the bottom of the overhang that's smaller, but that might be hard to get to on different designs of guns, they might have stuff closer to the picatinny rail than mine so idk.

[XOIIO]

So, again this is a very early sort of design, but here's roughly my plan for the OLED display. I had to tilt it at a slight angle so that I could reduce height a bit, hoping to keep it under 17mm height when mounted or so, and I'm thinking that the battery will be housed in the front unit, going with a flat lipo cell, and the control electronics will be in the front with the screen, this should let me get pretty compact for both, of course I still need a spot for the charging board and whatnot, this is just for me to print out and test fit on the gun, and with the oled and whatnot.

I also designed in some extended shields on the sides so that people to the left or right wouldn't be able to see any sort of blue light coming from your gun, but not at the top of it, so that you can still glance down and see without moving your head back too much.





Another thing is the connection between the two, I'll probably go with an aviation style connector, but they seem to be about 16mm in size, which isn't bad for the front module, it could come out the back on the same side as the overhang, but that is a little large for the oled section.

I could hardwire it in, but I'd like the connectors to be on both sides so that you can change the length or have different options, but maybe it would be better to hardwire the OLED screen part, and just have to figure out how to handle a little slack wire.

The average person probably doesn't have the tools or want to solder six, seven or 8 different little wires, or the spare cable to do it.

Water resistance also needs to be considered for everything, I have a feeling I might end up using a clear resin to seal the oled in the case to protect it from water ingress.

[XOIIO]

More tweaking on the OLED case is complete, so back to working on the front. I'm hoping that a 6mm section of glass or plexi will be enough to protect it, I have a scope protector that was only 4mm and survived a couple hits.

Overall length is going to be a little longer than this still and maybe a bit more than I had hoped but I don't really want to go with a battery smaller than 800mah, not sure how long this thing will run.

Ordered some connectors and other misc parts, so this will start to slow down a bit as I'm stuck waiting for things to arrive here, but I should be able to at least start programming a bit sometime next week once the connector breakout cables arrive.

Also, the glass/plexi protector will be held in with some screws from the front so it's easy to replace if damaged over time. I'll likely be using carbon fiber PETG for the printing of this with threaded inserts for this part, and as long as it's not a major pain, the picatinny mounts too.

[ThunderCactus]

I like both
Now make it fit under a DEVO's periscope and make a periscope to make the distance disply IN the reticle of the DEVO lol

[cetane]

If you have the space, I’d suggest rj45 plugs on the thing for wiring. Then it’s just a simple cat5 network cable. You can get it anywhere, and the connections are easy to terminate with a simple network cable crimper.