As promised, I've begun work on a Tutorial for "Fester". I'll get as much of it done as quickly as I can. Fortunately for our forum friends I happen to be slow at work right now. So, over the next few days, hopefully I can have a more or less complete tutorial, or at least have the mechanism part completed.
NOTE: I will be updating every post as I find issues or grammar errors.
Here's the parts list for "Fester" as described in the 2011 prop Challenge
Vent Motor $2.99 Motion
12V Wall wart $.75 (Garage sale) Power supply
2" Foam scrap $.42 Hand carved Skull
Scrap 1 X 4 wood $.02 Motor Mount
Scrap 1 X 6 Wood $.06 Base
1/8 X 1/2 Aluminum flat $.81 (5") Crank arm/Linkage
3/16 round bar $1.25 (18" of 36") Pivots
Scrap 2 X 2 $.04 Main Lifting bars (Used 1' and Cut down
4 Yards CHeese Cloth $2.22 Clothing, Skin
1 5/8" Deck Screws @ .05 $.45 (Used 9)
Tiny Eye Hooks $.36 (Used 6 from an 200 pc assortment pack)
Small Extension Springs $.28 (Used 2 from a 100pc assortment pack)
Fishing Line braided $.20 (Used approx 4')
#8 washers $.46 (Used 10 from a pack of 100)
1/2" Cpvc $1.12 ( Used 40" froma 10' section) Arms
Ultra tiney wood screws $.07 (Used 7 from my own stock Price is a guess)
thin strip 1" scrap foam $.01 Teeth
Automotive Vacuum Line $.33 (4" off a 50' roll, had in stock) Retainers
3m Adhesive $.25 a few squirts here and there
Meduim Ceiling Hanger wire $.84 12' For Guards, Joints, Hands
4" wide Duct tape $.40 (Used 4') Hands
Latex Liquid n $.75 (Used about 1 oz, 40% sale at Micheals)
Cotten Balls $.15 (Used 15)
Scrap $1 store eyes $.17 (Cut one in half at 6 for $1)
10-24 machine screw $.10 (One from my own stock)
10-24 Lock Nuts $.14 ( 2 from my own stock)
1/4 20 bolt $.11 (One from my own stock)
1/4 20 Locknut $.11 (One from my own stock)
Small self Tapping Screws $.20 (4 from my own stock)
1" Pipe insulation $.04 (1" section for neck)
Soaker hose used $.15 ( used approx 1.5' ) X .03 rule
Sample can wood stain 2.33 Used approx 1/3rd (Price guess, High?)
Various Spray Paints $2.50 Less than 1/2 can total
First, a word about the 3/16th" rod. There are two kinds of rod that are considered 3/16", Hot rolled and Cold rolled. I use Hot rolled. It looks less shiney than the cold rolled and has an actual dimention that is larger than the cold rolled rod. Cold rolled steel is exactly what is sounds like. When they made it they let it cool and then rolled it as it was cool. This decreases the dimention of the rod and will not work for this tutorial since several pieces are "Press fitted" into the wood. Cold rolled steel is also harder, but more brittle. I ran into problems with this discrepancey when I did the NJ/PA MnT build of the One Armed Grave Grabber
. So use the "hot rolled round rod found at HD or Lowes. It's NOT the shiney stuff.
You can use any wood you want for this build, but I recomend Oak or some other hardwood for the main moving parts. When I originally built Fester, I took an old piece of scrap square 1-1/2" oak molding and cut it to the dimentions I wanted. It was tedious and Dangerous. I recomend finding some square oak pieces at a good lumber yard that measures 3/4" X 3/4" for your moving parts. If you are good with a Power Mitre saw, then you can make your pieces from a 1" X 4" oak stock. It happens to measure 3/4" X 3-1/2". I just cut it in 4 sections Longways, to make 3/4" square stock. Feel free to upgrade to aluminum square stock or Channel stock which can be found at HD or Lowes. For now I will stick close to the original build and use wood (Oak) since there would be many modifications needed to use aluminum for the moving parts AND it would be Much more costly.
Ok I started by cutting these pieces of 3/16" round stock to these dimentions (HOT ROLLED, NOT the shiney stuff).
Then I chamfered the edges to allow better insertion into the various pieces of wood, ESPECIALLY the press fitted ones.
In the Picture above there are a few things to Note: The wood shown isn't 3/4" square stock. it's 1/2" BUT the dimensions are correct otherwise. Use 3/4" square stock.
The two tiney pieces of wood are identical, I just turned one upright so you can see the two predrilled holes to mount them to the base plate.
The other pieces have a few extra holes for adjustment in case you get the geometry wrong. They also include some adjustment holes for your "Assistance springs". Fester is VERY weight dependant and a heavy fester won't work well or last very long. I needed to use a spring to help in the lifting motion which I will cover in future posts.
Note that the two pivot arms have rounded bottoms to prevent interferance with the base plate when in operation.
Also note, I HIGHLY recomend a Drill press for ALL of holes for the main mechanism. Any holes that are not perfectly plum will cause binding and/or excess slop that will prevent fester from working properly.
Here is a picture of which holes will need to be press fitted. Press fitting reduced the cost AND reduced the "Slop" in the mechanism. Each rod shown is in a press fit hole prior to assembly. Note thier location and be sure to use the appropriate drill to get that ultra snug fit.
To make the press fit holes a 3/16" drill bit worked perfefctly with the Hot rolled steel rod. TEST the fit on some scrap wood (Same as you are going to use for fester)
To make the other "Looser" holes, I used a drill bit 1 size larger and tested the fit before continuing. I litterrally mean a drill bit that is 1/64th" larger than 3/16" (13/64") so that the remaining pieces can rotate freely with very little slop. TEST YOUR DRILL BITS with the wood you will be using to achieve a "Press fit size and a "Snug but loose" size before proceeding to cut and drill your pieces.
In the piece called "Spine" there is a press fit hole in the end of it to accept the neck rod. You can't see it in this picture but you'll see the neck rod in later pictures This is also a "Press fit" hole.
ANY resistance will affect fester since the motor is Pushed to the max. Find a drill bit combo that will work for you.
Here's a picture of the base plate with some measurements written on it to help you locate the pivot points. It also shows the location of the motor mount wood. It will be screwed into the side between the lines shown. You will have to mount your motor and linkage and run it without it being attached to get the desired motion. it sometimes takes two people to do this. I used 1-5/8" deck screws to secure the motor mount AFTER the motor is installed. More on that later.