BIG gun safe RFID conversion

Lever, so I’m not sure precisely how I can make it stronger but I have a few ideas to make a picker very unhappy

Primarily I think lll just screw a small metal placard over the key way, and put like 8 tiny screws on it if I’m feeling sassy, maybe 1 or 2 normal size but with as weird of a security drive as I can find

Nothing that will stop someone from picking

But I can make it take a while to even get access to the keyway, because it will also take me a long time to get to it if I ever need lol

Remember, a beefy angle grinder would eat most safes either way

Alrighty… next step of progress
New lock

Got a new digital safe lock with a pivoting lock, (forget the actual name for that style, but it’s better and lets solenoid shut with lock still open which is good)

How it works normally

How the backup key works

Lock module opened up… a bit more “interactive” upon initial opening, a few springs like to fly and not wanna go back into place thus the thumb and magnet

The 2 large solder connections below the solenoid I was very carefully able to hold everything together, punch in a combo and hold multimeter probes

Got a reading of 3.5v when the lock fires, new to solenoids so not sure if that sounds right but I was able to verify that reading multiple times

I figure I’ll run wire in the side of the lock and solder directly into those points so I can apply voltage directly to the solenoid,

Question is, can the xEM access controller control a solenoid like this? I would assume so

This is more or less what I’m thinking for mounting
Red will be a block that replaces the dial, but matches original screw holes in the corners
Blue is new lock module which I’ll connect to
That adapter block, I’ll trim that sliding bar to mate up with the lock pivot

One point that I may have made a bad assumption is I assumed the hole that goes thru the door would be the same size as most other digital safes, a 1” hole… I have concerns the hole will only the size of the combination dial rod… 1/4-3/8”

I’ll likely need to drill the hole much bigger, that may get interesting depending on the hardness and thickness of the front door

Depending on how it’s setup, it may be giving it the full 4.5v and the solenoid is pulling it down to 3.5v. Kinda like how the lights on your car dim down when you start it. You could unhook the solenoid and measure the output without it, but I doubt 1 volt is gonna kill anything.

Easily. You have two choices though.

First Remove the circuit board entirely and just use the lock’s mechanical mechanism with the xAC.

Second, leave the circuit board in place, but put a diode on the positive side of the circuit board output. Then add the xAC wires to the solenoid AFTER that. This prevents xAC power from backfeeding the circuit board and potentially mucking it up.

Also, the xAC runs on 9-12 volts. You’ll need to reduce that to the solenoid. You can get a voltage regulator which is just a simple small chip to drop it down. Some come with preset voltages and 5v and 3.3v are pretty common. I think the solenoid should handle 5v.

Also, Also, You need to consider some way for the xAC to “sleep” when not in use or it’ll suck the batteries dry over time. It doesn’t use much power, but it’s a constant drain. Or, you could run A/C power into the case and just use batteries as a backup.

Ripped out the old lock,

good news I have more front options than I thought
And the adapter plate shouldn’t have to get too crazy (even found a ready to go plate that might work for 20$)

Bad news the thru hole is too small like I feared
Also the hole isn’t centered, I would really like to expand the hole upwards instead of symmetric, but that might be tricky

I could already get really down and dirty and just use a dremel drum to expand the hole how I like

Made some progress
Got the new lock mostly installed, still needs to polishing of the locking bar and the ribbon currently blocks too much of the backup keyway
(I want it hard to see and hard to get to, but not impossible)

Once this is fully good to go, I’ll start trying to tie a xAC v2 directly into the solenoid


Mechanical combination to digital is completed

Now I’m starting to tinker with the rfid face plate
The rectangular pocket is much thinner that the rest and is where the antenna loop will reside
(Unless I can use a larger antenna? @amal)

The holes around the perimeter will possibly have magnets dropped in them while paused and then let the printer resume to embed the magnets in the final print

Thinking about adding an anti rotation element

Need to figure out what the xAC antenna connector is, I know it’s a common one but no idea on the name, want to order/make an extension, so the rfid face plate can be disconnected

Considering adding say 6 - 12 leds in a circle around the perimeter that illuminate on access grant for the duration

Ps, can a mod edit the thread title? Change it from a question to “big gun safe rfid conversion”


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I think it might be a little molex. But there is just so many of them.

Magnets near the antenna will reduce range / effectiveness.

You can build a new antenna, but it has to have the same inductance. It takes a special meter to check inductance, then you wind a coil that’s too much and check, remove a little, check again. Repeat till it’s right.

That sounds like a lot of sillyness I don’t need involving tools I don’t have

Boo on the magnets,

I was hoping to make this thing nearly a magnetic puzzle to get off

LCR meter (inductance (L ), capacitance (C ), and resistance (R ))

I agree with @ODaily

But yeah a 2 pin Molex would probably be the best place to start your search

LCR Meter

Same one I got. Budget meter, but should be workable. After that you’ll need magnet wire, soldering iron, and the molex connector with a long enough lead on it.

Should I even bother?

If x series read best when perpendicular to the antenna, would a smaller actually be beneficial, since I’ll more easily be in that position if I sweep my hand across the center?

Also made a bit more progress last night
Soldered in a few leads straight into the solenoid,
Still works with the digital combo for a nice secondary option
(I’ll plan to put that in a secondary secure location)

Apply 4.5v (as someone suggested not the 3.5 I metered) and it pops the lock

Now I need to figure out what I’m doing with power supply and routing of wires

Follow up question before I try to order molex stuff

Will extending the antenna loop by about a foot mess with the antenna tuning?

Yes, but it should still work fine. Especially at LF

Should I even bother making a larger antenna loop?

If you can avoid it, then no. Using the intended antenna is better and easier. Boo more work

Fair point,
Just wondering does a bigger antenna equal more range typically for x series?
I’m assuming with the xAC, it’s not going to change amount of power going into the antenna, just change field shape

Range is likely a combination of field shape and power right?

No, infact smaller better tuned and more powerful are all good things for the x series. Having a coil antenna is the best e.g. the xAC rev1

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yes this is true… but it’s tricky… the larger your antenna is, the more conductor length there is, and the more length there is, the more power you need to overcome both internal resistance of the added conductor length, and the physical space the magnetic field now needs to permeate… so just making a bigger antenna is not going to cut it… and adding a smaller antenna might result in it being overpowered, distorting the field such that your reader can’t really “hear” the tag trying to talk… basically if you overpower your field then you get this cascade of noise as the field collapses on each polarity change… that can happen 125,000 times a second for 125khz readers and 13.56 million times for 13.56mhz readers…

Basically the best approach is to design something from the ground up to get the best performance from an x-series chip vs a flat card or fob… but that’s just not happening out there in the real world, so we try tricks to improve performance as best we can. Sometimes simply changing the antenna to a different shape might do that, or adding another passive antenna coupling to the existing antenna to change how the field is shaped…

These videos show just how malleable and strange magnetic fields can be. The LED device in the center of a Bullseye NFC tag works great at range but gets choked to death at close range with the addition of the larger Bullseye tag’s antenna around it.


Got some molex make and female leads… I think I have the right connector, will find out when I get home and get a chance to plug in

Also going to try using a buck converter to get me to 5v for my relay power

I’m still a little confused which leads to need to attach relay power to, I know yellow is the NC, but what do I connect the other side to?