halloween projects - Page 1
Forum section: electronics / projects

author: KTP
author_rank: Frequent Contributor
timestamp: June 30, 2010, 05:47:59 pm
content: Hi guys,Halloween fast approacheth and I am starting to think of new stuff to create for this year's party. I would like to hear about cool Halloween stuff you guys have made.To kick things off, here are a couple of projects my wife and I made over the past few years.(yes, we are crazy)Fully automated two person "Doombuggy" ride.This was a quite involved project which taxed my limited welding skills and required a lot of work from my software engineer wife. The vehicle consists of a lower platform with servo controlled gearmotors driving go-cart type wheels and also a center gearmotor which can rotate the upper platform independently. What this means is you can get a very cool motion of rotating while moving foward or backward. It also allowed us to *hide* props from view and build the entire ride in a 25 foot by 35 foot garage. The software side of things was interfacing everything over 802.11 wireless and also writing machine vision software for a usb webcam to track a line drawn on the garage floor. We used a usb barcode reader to pick up tags on the floor marking locations where events need to be triggered. One year we did a pirate theme which was pretty cool but somewhat disjoint, the next year we did Frankenstein's monster which had many electromechanical props including a rotating gurney to allow the *monster* to disapear when lightning flashed and the lights briefly went off and also used a 12 foot linear motion rail hooked to the monster which allowed it to *chase* the doombuggy (the doombuggy was traveling foward but the top turrent was rotated backwards toward the chasing monster). The video here is from the first year with the pirate theme....my wife made some changes to the software the next year for a much smoother turning during line following.Here are a couple of pics of the doombuggy during construction:http://www.skyko.com/halloween/doombuggy/doombase2.JPGhttp://www.skyko.com/halloween/doombuggy/doombase3.JPGhttp://www.skyko.com/halloween/doombuggy/DoombuggyMoving.jpgAnd here is a short video clip from the first year while we were setting up props:Another much easier project was a computer controlled haunted ouija board I made back in 2005 or so (still works!). I used two stepper motors in a polar coordinate system connected to a rare earth magnet underneath the table. My wife wrote the software for the Atmel microcontroller. We had it play out many messages during the party and it was quite the hit. My favorite messages were "Don't drink the punch" and "Remember to drink your Ovaltine". If I were going to rebuild it I would use servomotors instead of steppers to try and get the electromechanical bits quieter. I had to add a sound chip to the atmel board so I could cover up some of the motion noise with music.

author: TheDirty
author_rank: Frequent Contributor
timestamp: June 30, 2010, 06:04:58 pm
content: I was really hoping to do some pneumatics, this year, but I don't know. Actuators and the valves are so expensive and I'm not good at trolling through E-Bay waiting for deals on these things.

author: NiHaoMike
author_rank: Super Contributor
timestamp: June 30, 2010, 07:49:54 pm
content: If you keep the pressure low (50PSI or so), you can use common sprinkler valves. Pistons can be made from PVC pipe and wooden dowels.

author: Time
author_rank: Frequent Contributor
timestamp: June 30, 2010, 08:49:44 pm
content: The ouija board is really cool.

author: KTP
author_rank: Frequent Contributor
timestamp: June 30, 2010, 08:55:53 pm
content: Quote from: NiHaoMike on June 30, 2010, 07:49:54 pmThat is a pretty cool idea. I happen to have had a bunch of valves and cylinders from a Boeing Surplus purchase (before they closed up) but if I ever need a cheap really long travel solution I might try the pvc pipe/dowel idea (thinking now of a 50 foot T-Rex in the front yard animated by 12 foot pvc pipe actuators)

author: TheDirty
author_rank: Frequent Contributor
timestamp: July 01, 2010, 12:45:54 am
content: I've seen the PVC home made actuators and the ones that use screen door cylinders. I wouldn't have been able to use them with the display I wanted to make, which is a Zombie ground breaker.