Laser clock on a wall

[wombweller]

Hi all

I looking at creating a clock for my wall and could do with some design ideas and inspiration.

The clock hands would be laser beam or similar and the numbers will be painted on to the wall. the main area or 'workings' of the clock will be bottom center and the numbers displayed in an arc.

The workings will need lasers for minutes,seconds and hours.I'm thinking I will need three lasers to show these but that might prove not to be so.I thought the type of laser found in levels will be good.

I'm open to idea's on this especially on what the main workings should consist of to get a working model.

To try and emulate what I'm thinking of I have included a simple drawing.


Looking forward to bouncing ideas



Regards

 

[crutschow]

The main problem, of course, is controlling the laser beam to generate the display. Do you have any ideas on that?

One way is to use two small mirrors controlled by galvanometers to move the beam both horizontally and vertically (see this). Or, if the laser is a wide beam such as from a laser level, then perhaps you could just incrementally rotate the lasers mechanically with stepping motors. It could all be controlled by a microprocessor.

 

[Dr_Doggy]

I was also wondering , what kind of resolution could you get with that?

 

[wombweller]

The main problem, of course, is controlling the laser beam to generate the display. Do you have any ideas on that?

One way is to use two small mirrors controlled by galvanometers to move the beam both horizontally and vertically (see this). Or, if the laser is a wide beam such as from a laser level, then perhaps you could just incrementally rotate the lasers mechanically with stepping motors. It could all be controlled by a microprocessor.

Hi

I will look further in to Galvanometer as it seems to be an interesting thought.

I was thinking along the lines as you said with using stepper motors.Thought it sounded too obvious as a method and was searching for a more refined solution. The KISS approach is the only thing I do!!

I will probably require three motors to drive the lasers independently or use one and the gear up to give the required ratios, the problem I envisage with gears is getting the arc I require.

I wanted to put this out for design ideas as I'm struggling.


Cheers

 

[3v0]

I have been thinking about using the voice coil drives from old hard disks. They are deadly fast and have a decent amount of travel. It could be possible with a bit of math to use a single mirror with one fixed point and a drive voice coil on each of two other points. A trianagle. Use a first surface mirror.

 

[wombweller]

I have been thinking about using the voice coil drives from old hard disks. They are deadly fast and have a decent amount of travel. It could be possible with a bit of math to use a single mirror with one fixed point and a drive voice coil on each of two other points. A trianagle. Use a first surface mirror.

Hi

Interesting thought, do they respond to the amount and type of voltage put through them to work?

Not sure I understand from your description how to get three time indicators.It would be nice to use one laser for the application.

Cheers

 

[3v0]

Not sure. I was thinking one could keep it with the original PCB and send it step command. But thinking about it I suspect it will be looking for feedback from the disk/head telling it where it was at. So it may not be such a great idea.

EDIT: I expect you could work out how to position them without the original electronics. More of a power thing then just voltage. (IV)

About the 3 point thing.

Think of the three points of a triangle. On each point put a ball joint. The first ball joint is just a pivot. The other two are connected to voice coils. By moving the two points you should be able to tilt the mirror two axis. Travel will be limited but enough to deflect the beam. The trick is that the X and Y axis are independent.