Wanted: Someone who could build a RC Wall Clock (time set by hand held trasmiter)

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gingermagic

New Member
Hello all,

I am a Magician in the UK working on a new show. We need an analogue wall clock building that we can set to a time manually using some sort of hand held device. I'm not sure if this would need to be built from scratch, or if an existing RC clock (which gets the time from national transmitters) could be modified.

Can anyone help us with this?

Time is really pressing for this item but we do have a reasonable budget to get it completed.

If anyone can help, please get in touch with me as soon as possible. If not, does anyone know a good place that I could ask?

Thanks
Damian
 
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papaof2

Senior Member
I can't help directly (cost of device plus fast shipping from US to UK + Customs would probably be prohibitive), but some details would help with the design

1. Is line-of-sight control acceptable (like a TV remote) or do you need through-the-crowd (or through walls) control?

2. How big does the clock need to be?

3. Does the time setting need to be only hours and minutes or do you also need seconds?

4. How quickly does the time need to change (advance/retard 8 hours in 10 seconds or 2 minutes)?

5. How accurate does the clock's time keeping need to be (seconds per day, minutes per day)?

John
 
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papaof2

Senior Member
The trick is only ruined for those who frequent this forum - the rest of the world will never know. If the remote is small enough or sufficiently well disguised, it won't be visible to the audience.

Hopefully the original poster had thought all this out, but the magicians I've known were idea people, not engineers - including an uncle who dressed in asian costume and used the name Fu Ling Yu.

John
 
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Odessa

Senior Member
Hey, Damian, Iff you tell me the trick behind the 'catching the flying bullet in the teeth' trick, I will build this for you!.....

Just kidding, but I would like to know how that trick works, although, reputedly, it didn't work for some "magicians" and ended with mortal consequences.....

I have an idea for you, though: most analog wall clocks (I think this is what you are asking for, although you specify a "building"??) are set via a dial on the back that is turned by hand. This single adjustment usually controls minutes and hours, and the second hand either keeps turning or can be made to stop when the dial is pulled out to make the adjustment. If you have the type where the second hand keeps turning (the least expensive, probably most common), then all you need to do is to glue or otherwise fix a gear to that dial or knob, then connect it to a suitable electric motor (with enough torque to turn it). A fast place to start would be a commercially available remote control (RC) toy, like a racing car. The controller and car both have batteries, but the car batteries are usually Ni-Cd or Ni-M hydride, which are able to handle large surge currents to a motor as the load. So, these racer cars may have a motor inside that will provide the required torque.

If you go with this solution, you have the wireless control, which does not have to be line-of-sight, you can buy it today at a toy store, and there are no R&D costs except the mechanical interface between the motor and the clock setting dial.

Good luck, Odessa

PS If that idea won't get me the shooting bullet trick explained, how about Chris Angel's walking on water trick (there is a You-Tube video where you can see him walk across the surface of a full pool with people swimming inside, and he drops his shoes in the water as he walks across from one side to the other!)
 
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Andrew Cowan

Senior Member
Odessa said:
how about Chris Angel's walking on water trick (there is a You-Tube video where you can see him walk across the surface of a full pool with people swimming inside, and he drops his shoes in the water as he walks across from one side to the other!)
Click to expand...
Pillars of glass, apparently.

I like Odessa's idea, but I would use a sail winch servo (about £20). That way, you can set it to an exact time without looking at the clock. may be a bit big to cram into a clock , though...

A
 
hippy

hippy

Ex-Staff (retired)
The analogue clock I recently dismantled to extract the MSF receiver could probably be modified to work in this trick. AFAICT the mechanism is two 'solenoids', one driving the seconds hand, the other driving the minutes/hour hands. Both are driven independantly so seconds ticks can be kept going accurately while minute/hour is adjusted at high speed. There are a number of cogs with tags which an IR break sensor reads so it can move the hands to midday etc when a new battery is fitted. After that I presume the solenoids are driven just like a stepper motor, if you counted the ticks you'd know where the hands are.

That's probably a way forward; synch the clock hands, set the actual time, then when it needs to do the magic, kick the solenoids at the desired rate rather than once per minute / once per second.
 
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gingermagic

New Member
papaof2:

1. We could probably get away with line of sight, but through crown would be more reassuring.

2. About 30 cm seems standard for an analogue wall clock.

3. Just hours and minutes.

4. About 20 seconds would be good. The hands may need to move independent of each other to achieve this.

5. Clock doesn't have to keep time. It appears to be broken and just stays on whatever time we set.

Dippy:
Sorry

papaof2 (second post):
The clock time will be changed by a third party. Not the magician.

Odessa:
You'd be SO disappointed if I told you how either of those tricks are done! However, if you want to be one of the people making up your solution for us then I could expose one of them to you as part of your payment?
 
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Andrew Cowan

Senior Member
The MSF reciever clocks reset to 12 o'clock before setting a new time, as this is the only location where feedback is given (via the IR sensor).

Andrew
 
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KMoffett

Senior Member
I think Odessa has the most workable idea. Since gingermagic doesn't need it to run, you could use a 1.5v battery-driven wall clock. The time set is just a rotating wheel. Glue a coupling to the time-set wheel, on the back of the module, that can attach to a motor. An external battery and relay or transistor to turn the motor on. This could also power an R/C receiver. As for the R/C portion, this is what I did with a ZipZap car ($10US at Radio Shack).
http://www.picaxeforum.co.uk/showthread.php?t=8598
More info at:
http://arttec.net/Press/ServoMag8-06/Zip-Zap_article Servo8-06.pdf
Actually, only one of the outputs would be needed for turning the motor on/off via a transistor or MOSFET. The transmitter could be reduced in size by removing the case, and possible even more by cutting out the car-charger portion of the PCB.

I used one of these for a remote control gag gift for the departing president of our College.

Pretty cheap, if you can get some local technical help.

Ken
 
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bgrabowski

Senior Member
Odessa the answer you are seeking can be found by Googling "Chung Lin Soo". He was one of the many victims of the bullet catch trick.
 
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eclectic

Moderator
Possibly a little OTT, but,

with a Stepper motor, you could change the time

forwards OR backwards, depending on the "Magic"

e
 
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Odessa

Senior Member
Hi Gingermagic: Thanks for the offer, but I also am on the other side of the Atlantic, so it would not be quick for me to assist you with this.

If you can't find any takers here, though, go to the nearest University where they have an engineering department and find a mechanical engineering student, or an electrical engineering student, maybe in third or fourth year, and offer them the project. Students are always hungry for extra cash, and using the solution I recommeneded above, it should not be that difficult for them to do it for you.

Good Luck, Odessa.

PS I don't want to be disappointed, so don't reveal the secrets behind those tricks; but, maybe you can say why some bullet catchers mortally caught the bullet with the back of thier throats instead of with thier teeth, like they were supposed to? Man, had they been a small fraction of a second faster they would have had the bullet in their teeth instead and lived to do the magic trick again another day. Can you at least say what went wrong for them?
 
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Odessa

Senior Member
Ken, please note on your Zip-Zap ckt., receiver side, you have F signal feeding Q1 base, but Q1 collector is labeled "Backward"; Q2 collector is also erroneously lableled "Forward". Simple transposition errors.

Regarding the 47 MHz, Zip-Zap rcvr/xmtr ICs, did you buy those at Radio Shack? Who makes those ICs, and what are the real part numbers? How much distance can you typically get with that wireless comm, maybe 40 feet?

Thanks, Odessa.
 
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Andrew Cowan

Senior Member
Will you be looking at the clock as you set it? If so, it would be incredibly easy and cheap, using the innards of a zip-zap car to control the clock motor. Simple.

(I'm talking about an MSF fast clock motor, by the way).

A
 
K

KMoffett

Senior Member
Odessa said:
Ken, please note on your Zip-Zap ckt., receiver side, you have F signal feeding Q1 base, but Q1 collector is labeled "Backward"; Q2 collector is also erroneously lableled "Forward". Simple transposition errors.
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No, they are labled correctly. The change from F to Backwards and B to Forwards is because of the the way I had to use their output voltages to get positive logic out.

Regarding the 47 MHz, Zip-Zap rcvr/xmtr ICs, did you buy those at Radio Shack? Who makes those ICs, and what are the real part numbers?
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I think I bought them at a hardware store at Christmas several years ago. But they are still sold at Radio Shack. The IC's are BOB's (blob-on-board), unmounted IC's covered by a blob of black epoxy.

How much distance can you typically get with that wireless comm, maybe 40 feet?
Click to expand...
Maybe 3 to 5 meters. Might be further with longer antennas.

Ken
 
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Odessa

Senior Member
"I think I bought them at a hardware store at Christmas several years ago. But they are still sold at Radio Shack. The IC's are BOB's (blob-on-board), unmounted IC's covered by a blob of black epoxy."

Ok, thanks. Seems you are in GB? I have never seen those sold at a Radio Shack in the USA. I just did a search for them on the Radio Shack website, but found nothing....is Zip-Zap the name of the company that makes them, or the name of the wireless link type, or the name of the boards those ICs are on? Can you provide any further information that might help me identify them and locate them, please?

How long of an antenna did you use, just a few inches?

Sorry for pointing out what appeared to be an error on your schematic, and thanks for spending time answering these questions here.

Odessa
 
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gingermagic

New Member
Thanks for all of the posts letting me know how easy this will be. Unfortunately, I do not have the time to put into learning any of this myself. If any of you would like to be paid to produce a good, quiet, accurate solution for us, then please PM me.

Cheers
Damian
 
K

KMoffett

Senior Member
Odessa said:
Ok, thanks. Seems you are in GB?
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No...Minnesota

I have never seen those sold at a Radio Shack in the USA. I just did a search for them on the Radio Shack website, but found nothing....is Zip-Zap the name of the company that makes them, or the name of the wireless link type, or the name of the boards those ICs are on?
Click to expand...
http://www.radioshack.com/uc/index.jsp?page=researchLibraryArticle&articleUrl=../graphics/uc/rsk/ResearchLibrary/BuyersGuides/research/zipzaps.html&noBc=true RS's search engine is useless. Looks like the prices have doubled!

Can you provide any further information that might help me identify them and locate them, please?
Click to expand...
ZipZap is a brand name. The ones I used are the low end 1/64 scale models without proportional steering. Just Google: zipzap

How long of an antenna did you use, just a few inches?
Click to expand...
The cars come with about 4" antenna wires. I used about 1'.

Sorry for pointing out what appeared to be an error on your schematic, and thanks for spending time answering these questions here.
Click to expand...
No problem...it wasn't obvious what I did.


Ken
 
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