# Weasley-style Clock

Hi,

I am working on a couple of projects for a Harry Potter murder mystery party for when the world returns to normal and people are allowed in the same house again!

One concept is that players would need to find pictures of the Weasley family members in a scenario around the room , for example “ a photo Arthur Weasley in a Dentist chair.

They would then need to move all 9 hands to the correct segment of the clock (similar to picture), in this example move the hand with Arthur on to the Dentist segment.

When all 9 hands are in the correct location, a maglock would release a drawer below containing a clue.

Would then need the project to “reset” i.e reactivate the lock when the drawer is closed and in an ideal world move the hands back to their starting positions again.

Is this feasible do you think? And any pointers of where to start would be fantastic!

Seems like mechanically it would be a mmmm… challenge.

It might be easier to implement with a graphical touch-sensitive display of some sort.

Work out the mechanics, then we can help with the programming.

I think that the the mechanics would be the most difficult part of the project.
One idea:
Have a continuous rotation servo motor for each hand of the clock, and an RFID tag behind each image. The RFID tag would be picked up by a RFID detector module behind the clock. The Arduino can move the servo /clock hand until it finds the position that the RFID tag matches the desired position. What I don't know is how you could manually move the hands without torquing the servo. Maybe some kind of slip clutch?

The nine concentric shafts for the hands would be the hardest part. Then drive each hand with a mini stepper motor, with buttons for changing the position of the hands instead of physically moving the hands manually.

Hi all,

Thank you very much for your suggestions, I really appreciate the pointers and these have guided me along a trajectory.

So I have been working on a basic design and have attached some images to that effect.

I have revised the initial concept to go with six hands on the clock.

I have nested some incrementally smaller brass tubes in side each other of various length and attached each to a gear and a 1:1 gear on a stepper motor.

I have mounted the six stepper motor modules and wired these to my Arduino via breadboard and have run some tests and each are able to move independently forwards or backwards at various speeds, which in turn drive the clock 'hands' (which I have not attached yet) as once they are on it's going to be pretty permanent and will need to decorate the box etc.

I like your suggestion of RFID readers, however, I understand these can cause interference with one another, and having six plus could generate false positives.

I think the simplest thing would be a button to drive each motor to the desired segment, my next question is how easy would it be to wire up a separate button to control each stepper motor. It would only need to advance the hand one segment at a time (so total steps per revolution / 13 segments).

And then, if I were to put a limit switch to create the idea of a 'home position' would I then be able to activate a relay when all six hands were in the correct 'position' relative to 'home'?

Many thanks in advance on any steers !

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