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Topic: Turning rotational into linear motion (Read 273 times) previous topic - next topic

mattlogue

This is basic physics. It's embarrassing I have to ask..

I want system to keep door locked at night. Ppl forget. I had one a while ago but the maglock was weak..

If I had a heavy duty servo I could push/pull a steel square tube thru a larger one over jamb side into another. The tubes are 3/4" & 1" cold rolled steel tubes. The bolt is 4-5" long and "1 pieces are 2-3". Pan head bolts or machine screws affix the larger steel tube thru door to sheet metal on exterior side. Nuts secure that (wish I could weld!). There would be a spring that contacts on jamb side and door side to confirm to MCU servo worked. In case of emergency, a pull exists to break the armatures from servos and withdraw bolt...

What type of armatures though?
Just because I live in the states don't mean I care

Paul_KD7HB

Your use of the word "armature" is very confusing.

There are only two ways to convert rotary motion into linear motion. The first is a crank connected to your servo, but that requires a connecting rod with two joints.

The other is a rack and pinion. That requires a gear on the servo and matching teeth on the rack. You can Google to see how to make them.

Paul

gilshultz

You can also use a cam or jack screw! This response is to help you get started in solving your problem, not solve it for you.
Good Luck & Have Fun!
Gil


dougp

The other is a rack and pinion. That requires a gear on the servo and matching teeth on the rack. You can Google to see how to make them.
Paul
Poor man's linear actuator.
I don't trust atoms.  They make up everything.

No private consultations undertaken!

mattlogue

I'll go with a crank like the locomotives use, in reverse fashion of course. Probably make it out of thin wood so it can break in emergency, since I suck at coding.
Just because I live in the states don't mean I care

Robin2

Is there a possibility that you would need to open the lock from the outside when the Arduino / servo (or the power supply) has failed?

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

zoomkat

On the safety side, the latch bolt on the inside need to be made such that it is escapable incase of emergency. Perhaps make one side of the latch setup where it can be lifted/moved easily to un latch.
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mattlogue

Is there a possibility that you would need to open the lock from the outside when the Arduino / servo (or the power supply) has failed?

...R
Conundrum... That's the Crux of access control. I have a panel on exterior with fingerprint, rfid, and pin#. Inside I plan EspCam for facial... Eh the more complex it gets, the likelihood itll break is higher....

Most logical is non electronic, since the MCU failed... A proverbial key under the doormat. I haven't thought of emergency ingress... Maybe hide a pull Chian ran thru wall behind siding? Pyrotechnic to blow the locks off?

Secure it is... Advices from locksmith. One bolt 1/3 up the jamb, next 2/3 up. I had bad experience with maglocks... Even with laser alignment and constant adjustment, my wife could bust it in. Sure I had back up alarm to trigger this event... Still. It's an obsession..

Redundancy... One ESP asssert fails, perhaps a relay opens channel to an Uno, with a backup credentials database. Power I haven't considered, our grid is stable. Stabler than most UPS I've had... I considered a system of cycle charging and draining two SLA battery's, using that voltage to run cams, router, and MCUs. Not gone ahead with it though
Just because I live in the states don't mean I care

mattlogue

On the safety side, the latch bolt on the inside need to be made such that it is escapable incase of emergency. Perhaps make one side of the latch setup where it can be lifted/moved easily to un latch.
My plan is.. only planning now.. is something if a smoke or CO is detected, the doors unlocked and HVAC shuts off. It texts and calls.
Just because I live in the states don't mean I care

Paul_KD7HB

My plan is.. only planning now.. is something if a smoke or CO is detected, the doors unlocked and HVAC shuts off. It texts and calls.
And that all takes place even when your power is off?

Paul

mattlogue

Nope. Not without backup power. That's something I have to plan. I'm not focused on it because it's rare.

Son has MD and ASD. so I need to prevent elopement. I use a sliding set of dowels in his bed so he doesn't year up room. I tie it off with rope. Triple knot! He's like houndini
Just because I live in the states don't mean I care

Robin2

Just get a couple of deadlocks with keys?

Electronics are not always an improvement.

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

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