Monday, August 30, 2010

Building Wallbreaker Forms

This post will describe how I built the forms for the wallbreaker.  This approach will support cheesecloth in a way that will keep it away from all the strings and moving parts.  You can either use this approach or use it as a basis for your own.

Building the forms
I have made some templates you can download and use to create the cardboard pieces used in the following steps, available here.  These do not have to be perfect, in fact these forms give you a starting point which will be trimmed at least once while you fit the forms to the wallbreaker and test run the motor to make sure everything clears.  I used corrugated cardboard,to follow these steps you will need to cut out the number of forms specified below for each step.  I also use a hot glue gun to fasten all the pieces.


Cut out the templates for the chest as shown above. The form is built using hot glue as shown in the following pictures.

The completed form is pushed onto block #19 as shown below.  Run the ghost and make sure the dowels turning the head move in the slots without hitting the form.  You may also need to trim away part of one of the C3 pieces so the head is able to turn freely back and forth.


Cut out and assemble the shoulder forms as shown in the following pictures.  The dimensions for the large piece of cardboard are provided in the templates you can download above.  Cut out the piece of cardboard, then cut slots at the shown intervals.  Cut out 1 S1 and 2 S2's.  S1 is glued along the middle of the large cardboard peice, with the slots sticking out to either side.  Glue S1 so the short side is next to the thinner slots.

Once S1 is glued onto the shoulders, position the two S2 pieces as shown below, sliding them down over the dowels.

Next, place the shoulder assembly onto block #12 and attach it with a screw.

Now use hot glue to attach the flaps to the S2 pieces as shown below.  I like to use small pieces of masking tape to hold things in place for the couple of minutes it takes for the hot glue to harden.

You will likely need to cut some out of the S2 peices where strings need to go.  Make sure to check al strings, and run the  ghost to make sure everything clears.

Lower Arms
I use cardboard tubes left over from paper towels to build the arm forms.  Cut out 4 of the IR2 forms, cutting the slot as shown in 2 of the 4 pieces.  Cut out 2 LR2 pieces.  Cut a paper towel tube in half lengthwise.  You should end up with pieces as shown below.

Glue the IR2 with a notch 2-3" in from one end, and the one without a notch in about the middle.  Glue the IR2 piece onto one of the center blocks at the elbow (block #8 or #9, see below).  Note that I cut off one of the tabs sticking out, and I positioned LR2 so it would not hit the lower arm dowel as it moved.

The form will sit on the lower arm, with the IR2 piece with the notch down by the hand, and the other end sitting on the LR2 piece at the elbow (see below).

With the form cut, it needs to be trimmed to fit.  Position the form so it sits on top of the arm or slightly out by pushing the IR2 with the slot down over the lower arm dowel, then mark and cut a notch by the elbow that will allow the  upper arm dowel to move up into the notch.  When you see the video later, you will see how the upper arm will move into this notch when the lower arm is pulled up, and how the form will slide out onto LR2 when the lower arm is lowered, but not slide off.  For now, make sure the notch is just wide enough so the dowel can slide up into the notch without getting stuck (see below)

Trim enough from the form by the hand so the hand can hang freely, and the hand does not hit the form when the ghost is in motion.

Upper Arm

The last form is the upper arm.  I also made this using paper towel cardboard tubes.  Hold the tube up and cut the tube a little more than the length you think you will need.  Cut one for each side.

Cut each tube once lengthwise so it can be opened up.  Cut out 2 each of forms UR1 and UR2, and glue these into the open tubes as shown below.  Make sure UR1 and UR2 are mounted in different directions for watch arm (see below)

These forms snap onto the upper arm, with UR2 above UR1.  Trim the cardboard tube up to the edge of UR2, this gap will provide room for the moving dowels at the top of the arm.
Trim the bottom so it does not hit the lower arm or form while the ghost is in motion.  You can see the forms all mounted on the wall breaker below.
The next step is up to you, what do you want you ghost to look like?  Just try to keep it light.  For the original Wallbreaker I used black broad cloth (cheap at WalMart) and cut pieces that would drape nicely over the forms.
Next, remove the forms from the wallbreaker so you do not get glue or anything else in the lines.  I used an Elmer's glue/water mix, dunked the broadcloth in it, squeezed it out and then applied to the forms.  Hold the form up so it is oriented like it will be on the ghost, and apply the glue/water/broad cloth over the form, introducing wrinkles, etc if you like.  The end result may look something below.
Next I used cheese cloth treated in RIT or whitening detergent, and fabric stiffener to add cheese cloth to the forms.  This is a good time to start adding texture or accents using the cheese cloth.  The result when shown in black light for my ghost is shown below.
The final step (if you like) is to add some more cheese cloth to fill the voids.  Initially I draped some cheese cloth over the forms, but I did not like it (see below) and I decided not to go with this approach.
The next approach I used was to cut some pieces if cheese cloth that could fill some of the voids, and use small dabs of Elmer's glue to secure the cheese cloth in place.  The result this looked like that below.

The video showing all of this in action can be viewed below

Saturday, August 7, 2010

hands, head and forms

Once the mechanism is built it needs to be covered so it looks like a ghost. This blog entry will cover prepping the head and hands, and getting the first layer of cheese cloth on.  The next entry will cover building the forms for arms and torso.

I have been building hands using newspaper and masking tape to build a simple form, then applying paper mache over the form.  I use my own hand as a model, then exaggerate the length of the fingers.  You don't have to be too picky about the result in terms of texture and form, i.e. if the knuckles are a little big, or if a finger is a little crooked, or the finish isn't completely smooth you likely will not notice.  The hands (and all the forms being built for the ghost) will be painted black and covered with cheese cloth.  Only the cheese cloth will be visible when the ghost is in operation in the UV light, so that and not the forms are the focus for the final appearance.

I ball up some newspaper for knuckles, then role the knuckles in some masking tape to make the fingers.  After making the fingers, I taped these to a piece of cardboard cut to the size of the desired hand (minus the fingers), then tape some additional small newspaper roles along the back to form the hand bones.  For the leer ghost I bent the hands to cup them some and give them a 3 dimensional look, and curled the fingers slightly.  Finally apply a couple of layers of paper mache, giving the hands a final forming to get the look you want. 

While the hands are drying I got started on the head.  I used a block with a 23/64" hole (that is 1/64" larger than a 3/8" hole, perfect for holding a 3/8" dowel) inside the skull, then used a scrap 3/8" dowel inserted in the block to hold it tight against the inside of the foam skull.  Hot glue is then dripped in between the foam skull and the block.  This will provide a good way to mount the skull on the ghost.  The final step for preparing the head consisted simply of spray painting the foam skull flat black. 

I have found 2 basic approaches to applying the cheese cloth with the cloth stiffener.  The first approach consists of dipping the cheese cloth in the stiffener, squeezing out the excess, CAREFULLY spreading the cheese cloth out and applying to the form.  The stiffener should be the consistency of milk, add a little water to get the consistency right.  I cut several pieces of cheese cloth about 3" square to 4" square.  Any smaller and the cheese tends to fall apart while you are trying to spread it out after dipping into the stiffener.  Any bigger and it will be too big for the head or hands.  The result of this approach is rather ragged looking, with the weave getting spread out, and strands rolling up.  The result contains voids and what looks like veins.  I like to use this as a first layer.  Additional layers added later will build on this using a different technique. 


With the eyes shaped by the cheese cloth, the next step was to add the LED eyes.  I simply solder a couple of ultra bright 10mm LEDs together in parallel, along with enough wire to reach from the head to where the motor will be.  For now I attached a 2 AA battery holder on the other end to power the LEDS temporarily.  The LEDs are inserted into holes in the skull, and once in position hot glue is carefully added to the eye sockets.  This will hold the LEDs in place, and diffuse the directional light from the ultra bright LEDs.  If you make a mistake, adding a little more hot glue will re-melt the hot glue it touches, allowing you to adjust the eyes somewhat.

The hands are sealed with polyurethane, then cheese cloth is applied.  I used the same technique of dipping 3-4" squares of cheese cloth, squeezing out the excess, spreading out and applying.  In the case of the hands I purposely left some of the cheese cloth rolled up to simulate veins on the backs of the hands.

As a test run I mounted the hands and head on the mechanism.  A picture and video of the result is shown below.

Sunday, August 1, 2010

Leer Ghost Rebuild

Okay, I lied. It's almost August, and I need to get busy building things for this Halloween, so I decided to put the Ghost Reader plans on the back shelf for now since it involved a lot of new things that might not work. I am finally rebuilding my Leer Ghost. This was my favorite last year, at least one TOTer never made it to the front door under this thing and instead when screaming across the front yard. I loved the idea, but the movements were limited and I was not happy with the straight lines and visible dowels.

The plan is to use what I learned from the wallbreaker, and this time make the mechanism less complicated, more reliable, able to handle heavier ghost parts, and easier to reproduce. I also want it to look much better, more like a ghost and less like moving sticks. It always starts with sketching out the basic movements
First step is to rebuild the mechanism. It will use the trusty vent motor, and I will try to round off the measurements and use only 3/8" dowels.
Since I have the jigs for making the wallbreaker parts, I will use blocks with the same dimensions as the wallbreaker. The leer ghost will have a single axis around which the head (neck) and arms (shoulders) will rotate.  The leer ghost will use 5 1-1/2" by 1-1/2" by 1" blocks with a 3/8" hole in the center and in one side.  Thats a lot simpler than the wallbreaker.  There will also be 2 blocks (same size) that will have the 3/8" in the center, and 3/8" holes in opposing sides at  20 degree offset.
The leer ghost will have upper and lower arms that move independently, and the head will swing down to leer at TOTers standing underneath it.
Once all the parts attached, the leer ghost is painted flat black and is attached so it is in the corrcct position and the spiderwire is added. In the leer ghost, each line only goes through a single eyebolt, and the result is the motor works a lot less so I should be able to have heavier limbs and other ghostly attachments than I did with the wallbreaker.  I ran it for several hours today, no problem.

I am reusing the head from the original leer ghost, and I am borrowing the hands from the wallbreaker.  I will be making new hands for the leer ghost, that will be covered in the next entry, along with building the forms to cover the mechanism (and hide the dowels)
The final result works quite well as can be seen in the video below.  I also try to show how the various movements work.