Need advice - DIY electronic trap monitor - snares

Anyone have a good idea for how to attach a magnetic reed switch to a snare without it interfering too much with functionality of the snare itself? This is for a homemade electronic trap monitor. My feeble mind has been working on this for a couple days and I'm not coming up with anything clever. Here's an example of a magnetic reed switch, it looks like this and is typically found on alarm systems for doors and windows:
https://www.amazon.com/Normal-Recessed-Magnetic-Contacts-Switch/dp/B0056K5ZC2
The circuit switches ON when the 2 magnetic parts separate.

Obviously when the animal gets wrapped up in the snare, those 2 pieces need to separate to turn on the switch, or I need to find another better way to trigger the electronics. Another factor to consider in the design is I need to keep the waterproof box containing all the electronics safely away from where the animal will be, otherwise the equipment could be easily damaged.

Any suggestions?

Thanks in advance!!

A piece of fishing line should do it

A snare works by a critter pulling on it. So you just need your switch somewhere in the line of pull- i.e. between the noose and the anchor point. How exactly you attach it depends on your snare setup. But basically you just need to leave a loop of slack in the cable and attach the magnets across the slack so they separate when the cable goes taut.

Edit: I drew ya a quick phone sketch. Maybe this isn't what you're asking about at all, but it's what I pictured.

I would recycle a dead trail cam

Are you saying you want the magnet switch inside a box?

How big a container do you need for the electronics ? Or are you meaning the magnetic switch? I would screw the wired switch to the container inside and screw the movable magnet to a small piece of wood to set in front of the wired switch so it can slide away and activate the switch. I would secure a thin wire cable to the piece of wood holding the moveable part and run the other end of the thin cable through the bottom of the container and leave a small amount of cable hanging out the bottom and make a loop with a double farell . Then attach fish line from the cable loop to the snare so the fish line will pull the cable and move the switch magnet and set off the alarm . I would use small test fishing line so it would break when the snare was triggered. Probably need a piece of wood for a shelf to set the moveable magnet on to line up with the wired switch.

lol

Any thing reusable on the snare probably will not be after a catch, unless your using snare entanglement for quick dispatch.

Just a thought about the process, are you using something to read the circuit when it goes off. If so you are going to need something a bit more robust than what your speaking off, cost of such is pretty high to be losing in every catch. Just be mindful of this

Use a piece of pipe to anchor the snare with about 3 feet out of the ground. Put your device at the top and feed the “breakaway” inside the pile and out a hole in the side at the ground. Attach it to the snare. The catch breaks the alarm, churns out a nice catch circle and your device is safe at the top of the pipe for the next set.

KenaiKid, thank you kindly for your sketch. That's what I was thinking as well. What's actually got me stumped is the details of how to hold the parts to the cable. All I can think of is using a zip tie but I want to use something stronger that won't slide around. Maybe I can melt the zip ties on to the cable so they are resistant to sliding around. My preference would be to use wire rope button stops but my snares are already built so whatever I use has to go OVER the cable and not slide onto it, if that makes sense. Is there any hardware that can be bolted to cable that will form a stop or a stationary loop I can tie to? I am new to trapping and unfamiliar with the hardware available. It would need to clamp to 1/8" 7x19 Stainless Steel cable.

Edit: posted 1 hardware option I found below. I assume there are better options available, I just don't know them.

Sorry, I don't understand your question "are you using something to read the circuit when it goes off"

No, the magnetic switch will be as you drew in your sketch.

Edit: Actually, after reading Vermontsters suggestions, putting at least the wired portion of the magnetic switch inside the box is probably better than having it flopping around loosely on the snare's extension wire.

Planning on using a 1 liter waterproof case from Amazon.
https://www.amazon.com/gp/product/B00SSF7MQO



Yes I'm trying to figure out a reliable place to put the switch where it won't get torn up after every use.



Vermontster, that's probably a big improvement on my original idea which was having the switch on the extension cable.




One part I'm unclear on from your description, are you thinking both parts of the magnetic switch would be stored inside the container? Just getting the wired side of the magnetic switch inside the box rather than flopping around on the extension cable will be a big improvement in design.

Vermontster, thank you very much for your ideas, this is really an improvement over what I had imagined.

Well what's the purpose of the switch if your going to be there to check the snare any way ? How are you going to monitor the alarm makes quite a bit of difference in what you using to make the alarm

Trappers have wanted an alarm system for a long time to send a signal to them by phone or radio band for years, the cost is immense to do and not very economical compared to just checking them on a regular basis, most coded by law any way. Besides being against the law in may areas, just like you can't use a drone to check sets either, though I know it's now done all the time in places.

So I don't get why you wish a alarm on the snare ?

This is based on Vermontsters smart suggestions, but it seems like the better solution is having the wired portion of the magnetic switch stored inside the box with the rest of the electronics, and then have this type of eyelet magnet attach to the outside of the box, with a wire attached somewhere to the extension cable. I believe this is how the commercial units work. When the animal gets caught and tries to pull, it will pull this magnet off the box, and the alert can be sent. This keeps the electronics including the switch all safely tucked away.

I'm thinking of using something like this to attach wire
to the snare extension cable. As I said, my snares are already built so I don't have the luxury of adding inline parts to the cable anymore. Anyone know what this is called? It comes up on Google as Cable Loop-Cable Cargo Anchor. Anyone have a better idea?

Why a magnetic switch. A nail on one side stuck in a wad of aluminum foil for the connection is all you'd need.Let them eat it .Put your sensor anywhere you want.
just

Back in my day, we'd go check the snares by actually looking at them. Old school.

~ADC~

In places where I need to respond quickly to a catch, like near a home or business, or in a place I don’t want the turf damaged by the catch circle, I just put a cellular trail camera on it and be prepared to go at 3:00am...
If your goal is to just have a light or something you can see at a distance, I think you will find that to be ineffective because sometimes your loop falls and a fallen loop won’t trigger your light, and is no longer functional. You need to visually see the lock at the top to properly check and maintain a snare in working order, and that usually means getting close or having a clear line of sight with optics. Fallen loops are common in my area. Birds, non targets that are too small to be held, non targets too big to fit through the loop can brush by and knock them down, all kinds of ways that happens. And it happens plenty in most situations.
Unless you are within wire-running distance to the location, you will need a transmitter anyway. By the time you do all that, you might as well pay the $150 for a SPYPOINT link-evo with 100 free images a month and use that. And it can double as security camera, deer camera, etc.
Devices like you are working on are fairly simple in terms of engineering and design, and if they had much value on the snare line someone would be selling them.

loosanarrow, thank you. Those are all great suggestions and I appreciate that but I don't have cellular access in my area.


People are selling them. For example Telonics.com. I like to build my own when I can. For many reasons but here are 2: I can build these cheaper than I can buy them, and when I build it myself, I can make the solution as durable as I want.

~ADC~ thank you and you make a valid point. I'm still going to check the snares "Old school." For me it feels more ethical to go immediately to the trap when the animal is caught and if it's an unintended animal in the trap, I can then free it before it has to potentially die needlessly or languish in the trap. I like "Do unto others as you would have them do unto you" even when it comes to animals caught in my traps. Maybe that makes no sense to you, and that's fine. Keep doing whatever works for you.

HobbieTrapper it took me a while to figure out what you meant but those are some good ideas. Thank you!

I see. Heck if you get it all figured out, I might be interested in one if you can make them cheap. If you could get at least 6 watts VHF it would be useful for drive by checking and if you can get more wattage to get up to maybe 30 miles that would be even better especially for folks running near-home. Do you think you can do it cheaper than $150 for a spypoint? Most people have cell coverage the eastern US, but if it’s cheaper I might try something like that, and if I had no cell coverage I would probably need something like that even if it cost more.

loosanarrow, thanks for your encouraging words. I was hoping to do it for less but initial estimates are looking like more than $150 in parts off Amazon, which is obviously not the cheapest source for electronics and I'm not buying in bulk. I'll certainly keep you updated.

Anyone have a better idea for attaching a cable to a midpoint on a snare extension cable than this? It needs to remain fixed in place and not slide up or down the cable. I'm sure there must be a better solution out there

For your purposes crimped-on cage clips would probably work Tra.

https://www.amazon.com/Wire-Cage-Clips-Zinc-Plated/dp/B07YLHCZGP

How about, instead of using magnetic reed switches, you just used a stationary spring-contactor with a trip wire. Like this:

KenaiKid, thank you! That actually looks like a perfect solution!

KenaiKid, the magnetic reed switch allows us to keep the switch in a waterproof case with a magnet stuck on the outside. I think we'll be more able to tune how sensitive the switch is by using a stronger or weaker magnet and probably won't get that level of control with a clothes pin, which I think might lead to more false alarms. Definitely though if others want to try building this using different components, the more solutions the merrier.

Personally I'm not interested in a remote snare alarm, since my snares are lethal and I enjoy checking traps. But I see the draw for some people. My thought with the trip-wire switch is that it eliminates having a critical component, even the magnet, attached to the snare cable to get damaged or lost. I see the benefit of having the box sealed though.

Here's how I think I would do it: mount the clothespin contactor, battery and transmitter in a weatherproof junction box, which would need to be anchored solid out of the catch circle or up high. Attach fishing line from the snare to the pull-tab (cardboard, plastic etc), with the string run through a hole in the J-box. When the string is pulled, the alarm sounds but all the electrical parts are secure in the box. The only sacrificial parts are the tab and fishing line. You could probably even make it possible to reset without opening the box, if the contactor is right inside the hole.

Here's the type of box I'm thinking of. With or without factory penetrations. With mounting tabs for anchoring.

Yes I am saying keep both parts of the switch inside and away from anything that will cause damage like animal in the snare, critter chewing on it or causing it to open and have a false alarm or weather freezing the switch. Keeping the switch and electronics inside the container and I would recommend the container be made of metal to help protect it from Squirrels chewing on it.

Back before trail cams went all digital took hundreds of pictures easily. I needed to know when bear baits were getting hit with out spending fortune on 35MM film. I built some very simple trail timers to use on my bear baits.. I hacked into some small couple dollar digital clocks made my own timers. The switch to trip the timer was just simpler version of the clothes pin switch in KenaiKids post..The clock had it's own little battery would keep time when switch was tripped. It was simply a small plastic wire tie held the switch open. Small piece spring steel I salvaged from something came down on small brass screw..Timer would be places out of the way strapped to something solid like tree. Heavy fish line ran to the timer in such a way that it was less likely to be tripped by birds, squirrels or deer, all of which could trip them. But with the fish line tied usually to a large log only a bear could move. I could get an idea of when my bait was getting hit and that it was indeed a bear opening it. Then of course I put a camera on it to see what size bear it was. I also hacked into some 35mm camera's and rigged those..
But anyway back to your building a switch. You maybe over thinking it some. The little clocks I used all fit in a piece 1 1/2 pvc pipe with two caps. This made them very small yet weather proof and they held up well..They were also very inexpensive. I literally had just a couple dollars in each of them. That simple pull out switch I made could be used to trigger all kinds of different devices.
I'm not sure just what kind of alarm your trying to trigger?? light is very easy..They do make Blue tooth alarms for fishing Tip-Ups that alarm to your phone. Don't know much about them range or if cell signal is required. But my brother in-law uses them for night fishing on the ice..
The thing to remember is to try to keep it simple. The more clips and magnets and such you add usually can be more things to fail.. There was someone here on T-man years ago used a meter and checked under ice 330s. Was as simple as twisting wire on jaws running it up top so could check continuity. Trap snapped no continuity spud it out, got continuity trap is still set move on..

Being someone who likes to play with things and not one to throw things out..I still have my goofy timers even though they haven't been used in over 20 years..Was actually going to throw them out couple months back while cleaning.... But didn't couldn't get my self to.
So I went just now dug one out and they look like this (pic below) most will still turn on and work??

Mac

They have commercial units for this. How will you check these, with a handheld radio ? If so the range is limited, and that's with clear line of sight. If you want cell phone to deliver your message you need service at the actual snare sight. If you go with satellite there is a subscription cost etc. These units will cost you prob 200-500. A pelican case is a great waterproof holder for your electronics. Search the adc forum for electronic trap monitors.

Macthediver and eedup, thanks for your suggestions!

Planning on using a 1 liter waterproof case from Amazon.
https://www.amazon.com/gp/product/B00SSF7MQO



Yes I'm trying to figure out a reliable place to put the switch where it won't get torn up after every use.



Vermontster, that's probably a big improvement on my original idea which was having the switch on the extension cable.




Those are excellent recommedations, hadn't thought of those points. Weather freezing the switch in particular.

Unfortunately the radio, battery, and circuits won't fit in a case that small, otherwise that looks like a great option.

You didn't answer. I could sell you some that check with a handheld radio. They use entirely different tripping system than what you're attempting tho.

When I built my 35mm trail camera's they were cut into a Ammo can. The price on them now may be more than a pelican case I don't know haven't bought either lately.. The Ammo cans easily held a 6volt battery, cannon sure shot owl camera and the photo eye circuity. I'm told that it was the smell of the film that made bear chew the old trail cameras. I have to believe that is true because I had bears chew on them metal cans. Never had one chew on the little pvc timers or the digital camera's I have now.
The ammo cans worked very well with couple small bars riveted on to strap to the tree. I also build one into what I was told was a french army mess kit. That one became my favorite one because I managed to make it smaller.
I've been told by lots folks I think outside the box..My answer to that is I never knew there was a box? I've had my share of original ideas and have improved or modified things made by others. Building the timers and camera's was my very small adventure into electronic. I got the info on hacking cameras and photo eyes from on internet back in mid 90s..
I built 3 or 4 cameras for about the cost of buying one from people making them at the time. They weren't pretty but they work and did what I need them to.
Thinking about you wanting to use a magnetic switch and a pelican case? I would probably look at working with the magnet right threw the plastic case no opening.. Might work and you would only have to have extra part that pops off so if you loose it.
Don't be afraid to try things. When I make something for my self I'm the only one that has to be happy with how it looks or works. If it works as I wanted it to and people like how it looks great. If it works like I want and other think it looks like junk. No skin off me didn't make it for them..

Here is what the armored camera cases look like not pretty but functional.. Can even see where bear put tooth threw the plastic photo eye lens. It also cracked the glass over the camera lens too. I replaced that but didn't have another photo eye lens. Like so many other things I should throw these out. Actually did get ride of two these two were the best of the 4.






Mac

eedup, I'm going to try making my own, but thanks anyway.