Thinking outside the metal (steel) mailbox

I used a motion sensor inside the back mine. Works great though mine is made of wood. Probably 75’ from the bridge. If I had a metal mailbox and had connection issues. I would probably use a hole saw to make a 2” hole in the back and cover it from the inside with plexiglass or similar. Could then be painted on the outside to match your box. Mount the sensor on that piece of plastic and cross your fingers.

they cheap also fun how far we can push it to destroy it.
The thing will not kill no one when it rains.

If you pop the battery cover off is seal good. it would take a lot for water to get inside.

Amazon has some nice cases if you can’t print your own.

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Have you seen open bottom ones with a recessed hidden keeper latch, seized for a Wyze contact sensor sending unit?
Someone in the forum with a 3D printer would be a more likely source, with two case configurations: flat edge (reed switch) vertical or flat edge horizontal. The one I made and posted was a vertical model.
Victor Maletic

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I forgot to mention that the vertical configuration would fit in @raym64 situation and the horizontal version would work with @kroq83 situation.

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check these ThingVerse products out …

Hello avincent98122.
I was aware of the 3D printed items that are available, thank you. Others for sure would find your information useful. You and others may want to check out 3D Printers at libraries.
The extended antenna modification of my contact sensor worked for about 6 months until it failed due to faulty soldering. Instead of repairing the broken solder joint, I tried a different approach by extending the magnetic reed switch instead of the antenna. This approach has more useful applications and does not alter the sending frequency of the antenna.
You may be interested in the external reed switch modification I made for my mailbox contact sensor.
Here the link:
Thinking outside the metal (steel) mailbox - 2
Contact Sensor Modified - Magnetic Reed Switch Remote / Outside
I mentioned above that the external reed switch is a more useful modification see the below link for another application:
My Wyze Smart-ish Lock Another Approach

Til later Victor Maletic

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Hello jon_kelley11.
You may be interested in another way of making a contact sensor work with a metal mailbox. I was able to utilize much of the external antenna system when I switched to the external magnetic reed layout.
Thinking outside the metal (steel) maillbox - 2 and
Contact Sensor Modified - Magnetic Reed Switch Remote / Outside.

Excellent idea…I’m stealing that one!!!

Little tip from personal experience… when your mailbox sensor starts going off annoyingly every few minutes, before you go running around wondering if the battery is dying, the bridge needs resetting, or it’s just broken; go check if you left the mailbox door open. Oops! :blush:


You didn’t do that did you? :sweat_smile:

I had the same problem in spades - all metal mailbox set in brick!

Of course mounted the transmitter in the mailbox.

I made a similar mod, just using a length of wire equal to the original spring (just straighten the spring, cut a wire to the same length). I added a bit for the part that is inside the mailbox and that seemed to work. Figured if I needed to trim to increase range, it’s easier to make the wire shorter. Drilled a hole in the mailbox, used a grommet to keep the wire from chafing and putty to seal. Used some more putty to temporarily locate the new antenna. Since the same putty is holding the mailbox in, it’s pretty durable, so I may just paint it or press sand into it to match the mortar.

Configured the sensor to trigger the camera and turn on one of my Wyze bulbs in my office and change the color to cool white (normally, I have it warmer when it’s on). When the mailbox is closed, I have it change the color temperature back to warm.

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Hello WidGet.
Nice installation and cleaner looking than mine. I have since changed it to an external reed switch inside the mailbox with the sending unit outside and under the mailbox. Now nothing is visible unless you’re two and a half feet tall and look up at the bottom of the mailbox .
I think your sand idea is very good.
How did you mount the magnet?


I was trying to figure out a way to put the transmitter under the mbx, but I couldn’t work out a way to mount the magnet such that it would pull away from the reed switch given the geometry of my mailbox door.

Turns out the construction of the mailbox door is such that there is a die cast frame around the outside, with an inset metal plate. The rim of the mailbox sits in a groove in the frame (bezel?) for a better seal.

I was able to use the supplied sticky tape to affix the magnet to the metal plate on the door, albeit at 90 degrees from it’s normal orientation to the transmitter. Since it’s a reed switch, there’s some leeway in the orientation as long as you have the proximity correct.

Now we get to see how long the battery in the transmitter holds out.

Sure wish I had my V3 cameras to trigger… :wink:

Thanks for the reply MrWidget.
You have a very clean simply mounted transmitting unit inside your mailbox. However there are two situations that can be easily fixed.

  1. If the transmitter is bumped by mail or packages the unit will separate from the battery door that is attached to the inside surface of the mailbox. Also the separation impact could damage or break the solder joint for the antenna.
  2. In your current setup, changing batteries requires the transmitter to be separated from the battery door. Swinging back the transmitter to access the battery will put strain on the antenna solder joint.
    The fix to the above scenarios is to flip over the unit and attach its opposite face to the surface of the mailbox. The old adhesive should be removed from the battery door. Battery changes will not put strain on the antenna connection.
    As further step could be to attach a bumper bar in front of the unit to guard it. I would use small screws for the attachment.
    In the post referenced below is a method of providing bumper protection I used. Also shown is how I attached the magnet without relying on adhesive tape.

You’ve got mail part two post #1, Feb 18.

I’m seriously considering making a 3D printed cover to go over the transmitter to protect it. I have to make sure I can easily remove it though as I just got an alert that the battery is getting low (I’ve had the kit for a long time, but am just getting to deploying it). I didn’t look at the marking on the battery though so I’ll have to take the other one apart to figure out what it is.

The wire I used is a nice floppy silicone jacketed wire, but the putty may hold it in place such that it could pull away at the solder joint - that actually happened with the original antenna while I was trying to straighten the coil and is why I decided to replace it.

If I continue to use putty to hold the antenna in place, it’s relatively easy to loosen it and then get a lot of slack before opening the battery compartment. I was actually surprised how easy that was (since it looked like a sealed unit at first), so as long as the adhesive holds, I think I’ll use that, and when it fails, I have some really strong (3M) double stick tape…

I might just glue the magnet to the door when it eventually falls off or use the same tape as above.

What I like right now is that I have a solution that I think will work until the technology becomes obsolete, and when it does, I can remove it all with very little trace of it ever being there, and I should be able to find another solution that I can adapt.

I was going to roll my own, but doing extremely low power stuff well can be a pain - and I had this stuff on hand.

Since your battery is dying, this is a good time to disengage the sending unit from its battery door and replace the 1632 coin battery with a fresh one. Then peel off the battery door from the mailbox surface, slap a piece of the 3M where the old adhesive was, and place the opposite side ( twist the unit 180 deg ) against the new 3M adhesive. Next, clean the original adhesive off of the battery door and snap in place on the sending unit. You will have removed the weak link ( battery door interface ) in the connection to the side of the mailbox. The antenna wire will no longer be moved during battery changes, and the sending unit will be more resistant to mail impacts. Maybe 15 minutes work?
It will also look as good as before.
Whatever you do, carry on.
Victor Maletic.

I remember you mentioned 3D printing up a protective device for the sending unit. In the following post, I describe a 3D printed surround for the sending unit that LachLan6 printed from a file I developed and emailed to him. This printed item was meant for a contact sensor with an external reed switch. The wire slot in, your case, would not be used and simply filled in with epoxy or caulking. A hole for your antenna would be drilled as needed. This 3D printed unit would provide extra resistance against impact while maintaining access to the battery door. It also has a larger base accommodating more 3M tape, hence more resistance to being dislodged.
If you want I can email you the STL file and you could print as is or modify it to remove the wire slot while keeping the door opening recess.
Or I will send you a printed one that I have on hand at no cost to you. Or both a file and a unit.
My Wyze Smart-ish Lock a Printed Approach Because of the enclosure configuration the magnet will need to engage closely because the reed switch is behind the door opening recess.
Let me know if you would like the file, the print, both or none.
Till later, Victor Maletic.

I had to go find your youtube channel to see what you meant about the My Wyze Smart-ish Lock a Printed Approach - very clever!

You may be interested in the following posts that use modified motion sensor units. A more benign modification than the external antenna:

Thinking outside the metal (steel) maillbox - 2

Here is another link using modified contact sensors:
My Wyze Smart-ish Lock a Printed Approach

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