Introduction: Giant 555 Footstool
Since the creation of integrated circuits, there has not been any circuit more useful, more iconic, than the 555 timer created by Hans R. Camenzind. This simple circuit named after it's 3 parallel 5k ohm resistors, has enabled engineers and hobbyist alike to build simple and complex circuits since 1971.
To commemorate 45 years of simplifying circuit design, I wanted to build something that embodied my geeky electronic side while getting me out to the shop to get my hands dirty.
This instructable will show how to laminate 24 sheets of MDF to create a 45:1 scale model 555 footstool.
I built my stool using a layering technique that is demonstrated on this 555 timer stool that was posted several years ago on the Evil Mad Scientist website by Windell Oskay. That is the first ever 555 timer stool I can find online, and rightfully deserves credit for the idea.
Step 1: Design
This design was made by reverse-engineering a physical 555 timer IC then building it in Soldiworks at the larger size. It was then edited and sliced into 3/4 inch thick slices.
I have included all drawings in downloadable PDF form as well jpeg copies in this and other steps.
The included PDF copy of the stencil is also necessary for the detailed painting of the part number in later steps.
Step 2: Materials Needed
Step 3: Cut Body
Cut 12 copies of the body. I cut the body from blanks that measured 10 1/4 inches x 6 1/2 inches. This will form the middle portions of the IC.
Step 4: Cut Legs #1
Cut out the four sections of legs that will touch the ground. I cut mine from blanks that measured 16 7/16 inches x 11 1/6 inches Cut the first then use that as a template for the others.
Step 5: Cut Legs #2
Cut six copies of the half leg portions. These will sit next to the legs that touch the ground to widen the leg. I cut mine from blanks that measure 15 7/16 inches by 7 3/4 inches.
Step 6: Cut and Shape Ends
Cut two more shapes that match the twelve middle portions. Using a hand plane, shape the ends.
Step 7: Cut Angle on Legs #2
Clamp sections together and mark where to cut the shorter leg portions.
Step 8: Drill Interior Holes
I attempted to keep everything lined up as much as possible by taking extra care with creating registration marks across the top and making exact measurements for interior holes and using one middle section as a template for all the others. In the end, it didn't seem to matter as I was still off. Don't sweat this step too much as you will be able to fix all the irregularities later by removing the highs and filling in the lows.
Step 9: Test Fit and Prepare to Glue
Test it out. Put everything on the threaded rod and make sure that it fits nicely.
Step 10: Glue Main Body
Cover everything in glue. Learn from my mistake, lay something down so you don't need to clean up large amounts of glue. Clamp everything together. Wait for everything to dry thoroughly.
Step 11: Glue Ends
Glue the last four portions on the ends.
Step 12: Smooth and Shape
I ended up buying a belt sander for this project alone. A regular orbital sander will take forever depending on how much material needs to be removed.
Step 13: Glue Ends
Glue the remaining ends on, and sand everything smooth.
Step 14: Shape Between Legs
Remove the remaining unwanted material between the legs with a chisel and mallet.
Step 15: Cut Notch
Mark a semi-circle on one end with a diameter of 2 1/2 inches. Using a router, freehand the notch 1/2 inch deep.
Step 16: Make Room for the Washer
Use a holesaw, cut out a hole deep enough for the washer and nut. I wrapped the drill bit on the hole saw with painters tape to make it the same size of the hole.
Using a chisel, remove the unwanted material. Cut the threaded rod to length.
Step 17: Apply Bondo
Using a large paint stir stick as a putty knife, apply the Bondo. I probably applied five or six layers of Bondo sanding between each layer. Any irregularities here will show in the final painted product.
Step 18: Prime and Paint
I used this shellac primer because it seals up the MDF very nicely. Apply many many coats of primer as anything not covered will allow the black paint to soak into the MDF.
Step 19: Prepare Template
Print the PDF template on card stock and cut out the letters. Save the inside portions of the 8 and P.
Step 20: Transfer
Cover the top of the stool with painters tape. Place the stencil on the top of the stool and tape in place. Using a pencil draw the letters onto the painters tape.
Step 21: Cut Painters Tape
Remove the letters with an craft knife.
Step 22: Paint Label
Cover the rest of the stool to protect it from paint. Do a first coat of black paint. This will seal the edges of the paint. And if anything was going to seep under the paint, it will be the black paint that will seep. Wait till the first coat is dry, then paint a light coat of grey primer. I didn't want a heavy sold coat as most ICs I've see have more of a speckled print of the letters than solidly printed. Remove tape.
Step 23: Paint Legs
Using the same techniques as the previous step, tape the legs and paint.
Step 24: Touch-up
Do any touch up needed. I used a toothpick to fill in any irregularities in painting.
Step 25: Protect
Cover with clear coat to protect your new stool.