Help! I am trying to build a life size jack in the box that is activated when people approach. How would I go about doing this? What parts would I need to buy? What type of motor?

Thank you

 

I would start with a retail version of a proximity detector, one that turns a porch light on as people approach. That will give you 120 volts to run a relay or a motor. Then build the structure and decide from what the structure weighs what kind of motor to use.

 

I might look into pneumatics (air cylinders) too versus a motor..

Now only 500 "devils in the details" steps to go..
weight?
type of movement desired?
cycle times?
proximity distance?
blah
blah
blah

 

I agree pneumatics might be a practical solution, however the box and cylinder retracted would need to be ~50% of the final Dummy height, (sorry Jack).
Max.

 

I agree pneumatics might be a practical solution, however the box and cylinder retracted would need to be ~50% of the final Dummy height, (sorry Jack).
Max.

not necessarily.. mechanical levers,etc.. can take care of that..

 

Good thing you started thinking early. You've only got another four weeks before Halloween.

I would imagine that you want Jack to jump up fairly quickly. I would use a spring loaded mechanism that gets wound up with a motor. A latching mechanism locks it into place. A solenoid releases the latch.

 

An airbag approach might be doable. You could stuff one of those fan-inflatable characters inside and then use some combination of an air blast and a fan to stiffen up old Jack.

 

Several vids on you-tube...or, just make a box and hire a clown to pop up on command.

 

Get together with killivolt's Halloween project.
Proximity sensor triggers high voltage under pants of hired clown. Clown pops up when receives shock.

 

I am thinking about making the box 4ft x ft made out of plywood. The clown isnt very heavy I got him from party city. I am great with wood but horrible with electronics. I want the clown to pop up as people approach and then retract back in the box. If I could use a motion detector that would be great, but I honestly have no idea how to get the clown to spring up and out of the box.

 

but I honestly have no idea how to get the clown to spring up and out of the box.

Here is a start:

http://www.youtube.com/watch?v=eRRPcIjEMd4

Skip to 10:12 to see the mechanism description.

Those folks are the "experts" but I think the lid is too heavy. Motion is too slow - a result of the mass of the lid. It'll only get worse when the head is decorated.

There should also be a "stop" to catch the lid in the upright position to stop the springs oscillation of the lid and JIB.

Their mechanical release mechanisms could be easily converted to electrical with the use of automotive door lock solenoids.

Retraction might be accomplished with the use of a automotive wiper motor though I'm still stewing on how that could work.

joe

 

Want light weight lid? Try a Thermax insulation sheet. Foam in the middle, aluminum foil on the outsides. A couple of 2X2's to stiffen it so the sudden movement doesn't crack the Thermax.

 

Excellent idea!

We try to use foam everywhere we can. Easy to work with, carves easily, lightweight, paints well (with the correct paint) and can be reinforced with minimal effort.

joe

 

...or, just make a box and hire a clown to pop up on command.

I second this idea, it would happen in time and probably be cheaper
Max.

 

Can you get someone to hide behind the scene and operate it manually?

I'm quite sure the original "Star Trek" Bridge doors were manually operated.

 

I second this idea, it would happen in time and probably be cheaper
Max.

Can you get someone to hide behind the scene and operate it manually? I'm quite sure the original "Star Trek" Bridge doors were manually operated.

Please don't take offense, but it appears somebody is trying to suck all of the creative air out of the DIY room!

Invent something!! Create something!! Make something!!

joe

 

Do you want a creation or do you want the job done?

Count me in as another vote on the side of a manual solution. Cheaper, more reliable (with the right operator!), and probably more fun for both operator and audience. I assume FUN is part of the design goals?

 

Do you want a creation or do you want the job done?

An accomplished seasonal decorator achieves both - at the same time.

Some call us fun fanatics.

joe

 

Just thinking about the lid, air resistance could slow down the speed at which jack jumps for a lid of a reasonable size. Would a frame convered in speaker fabric be better as it would allow some air through?

 

You might need 2 catches. First one releases lid, which springs open and then operates the second catch to allow Jack to spring up.
Standard RC servo could operate the first catch.