Saturday, July 24, 2010

Wallbreaker howto update

Quick update on the wallbreaker.  First, I was having trouble with the line sticking to the eyebolts using monofilament. Several people suggested I try spiderwire, so I picked some 20lb spiderwire twine, and it worked great.  Nice smooth motion, no need to apply oil (though there was probably some residual on the eyebolts).  I ran it for 9 hours Friday without a hitch, this is the verion built for the how-to using the A/C vent motor.

Thanks to building 3 kits today, and feedback from Erebus over at HauntForum, the how-to has been updated with several fixes and improvements, including the use of pulleys for the torso movement.  If you plan on using it I suggest you dowload the latest, which is always available on the top right of this blog.

Below is a quick video of the wallbreaker built with the how-to (minus the hands and foam skull), including the pulleys on the torso movement.

Monday, July 19, 2010

Ghost Reader 1

I plan on remaking the ghost reader prop for the Haunt Forum technical challenge. I cannot win a prize, and I don't expect to compete with the prop controllers and servos sure to be entered, but I thought it would be a lot of fun to extend on what can be done with a single small gear motor.

The original ghost reader can be seen below. It uses a Boris talk through skull hacked with a computer speaker, and a wood frame covered with chicken wire to support the cheese cloth. A wiper motor swings the porch swing.

I think I have the movement figured out. Using an A/C vent motor will give me 4 RPM, or 15 second cycles. The idea is to have the ghost look at the left page for 7.5 seconds, look at the right page for 7.5 seconds, look up and left while the left arm reaches over to the top right of the book for 7.5 seconds, and finally look right and up while the arm returns to its position at the upper left of the book for 7.5 seconds.

For the arm movement I am going to try attaching one end of the arm to a pivot, with a plate moving back and forth to give the arm the reaching motion. The figure below shows the arm movement from the top, and from the back. Notice how as the plate approaches the center, the distance from the pivot to the plate shortens, causing the end of the arm (the hand) to raise up some as it swings past the center. You may need to click on the image for the animation to work.

animated arm

The second part of the movement was to figure out how to move the arm every other cycle. I came up with the contraption pictured below which will hopefully work.

2 in 1

More to come....

Sunday, July 11, 2010

Howto is finally done!

I have posted the how-to for the wallbreaker mechnism. It took way longer than I thought it would, but I wanted to do it right.

Wallbreaker How To

I have done my best getting everything right, but if you find problems or have questions please post them here.

Now I can get onto my next project. I will rebuild either the leer ghost or the ghost reader for the next hauntproject contest. I cannot win, but it will still be fun to enter. I will update here with my progress.