This instructable will show you how to build the Spinning Gear End Table. This project is made primarily out of plywood. The table top will be a box containing rotating gears within. The top of the box is covered by a sheet of acrylic, allowing the gears to be viewed beneath. The goal was to make a piece of furniture not only aesthetically pleasing, but interactive as well.
Here is what you'll need to build this.
Tools I Used
- Circular Saw
- Scroll Saw
- Pocket Hole Jig
- Jig saw or hack saw.
- Orbital Sander (Or just sanding blocks if you want to do it by hand)
- Iron (for edge banding)
Tools that would make the project significantly easier
- Table Saw
- Band Saw
- Drill Press (Please use a drill press. I had so many issues with misaligned holes)
- CNC Mill (I actually did have a buddy make several gears for me via CNC, but it is not required)
- 1 Sheet of 3/4" Plywood (I used a 4' x 8' Red Oak. I have lots of material remaining for other projects)
- 1" Dowels (This is for the center shaft of the gears)
- 1/8" Dowel
- Edge Banding for Plywood.
- 1 small sheet of 18" x 24" x 0.22" Acrylic (Found this as a standard size at Home Depot)
- Wood stain/finish of your choice
- Cut out the pieces for the table top
- Assemble the table top
- Cut out the gears
- Cut out the bevel gears
- Create and assemble crank system
- Attach gears to the table top
- Cut and assemble the legs
- Finish it!
Let's get started!
Step 1: Cut Table Top Pieces
I used 3/4" Red Oak Plywood. Since a 4' x 8' sheet was just too large to fit into my car, I had Home Depot cut it into pieces. 21" x 48" and 25" x 48." Do with the remainder as you will, but likely some will be used later for making the gears.. These pieces are slightly bigger than they need to be, and this is because the saw at Home Depot tends to tear the plywood at the edges. This way, I have some stock to cut off.
Make the following cuts.
- 7" x 19.5" (x2) (using the 21 x 48 piece)
- 7" x 24" (x2) (using the 25 x 48 piece)
- 1" x 18" (x2) (using the 21 x 48 piece)
- 1" x 22.5" (x2) (using the 25 x 48 piece)
- 18" x 24" (x1) (using the 25 x 48 piece)
I used a circular saw with a straight edge jig as a guide to make these cuts. There are tons of videos on how to make a jig for ripping plywood with a circular saw. I would highly recommend using one if you are cutting with a circular saw. These cuts could be easily made with a table saw as well (which I do not yet have).
I cut everything into strips measuring longer than their final dimensions. I then made cross cuts with a circular saw and straight edge to cut them to length. A table saw or miter saw would also accomplish this with much better results.
Cut these out? Great! Let's put them all together!
Step 2: Assemble Table Top
So you have all of your pieces cut out. Awesome. Let's assemble this thing!
1. Lay the 7" pieces into a rectangle to make sure they fit okay. Using a pocket hole jig, drill in pocket holes into the ends of the long pieces.
2. Place the large 24" x 18" panel upside down, and drill pocket holes on the corners.
3. Now you take the 24" x 7" piece and the 19.5" x 7" piece and place them together at the right angle as shown. I clamped these pieces together to keep them from moving. Make sure that everything is flush. Screw in your pocket screws. Repeat this with the other two pieces.
4. Place the pieces around the 18" x 24" panel. Clamp these pieces down and drill in the final pocket screws. You will now have a box with no top or bottom.
5. Lay down your acrylic sheet inside the box. Then place the strips inside along the edges of the box.
6. Take your 18"x24" panel and place it in the plywood box. If everything is tight, you may need to use a mallet to hammer it into place. You will want this piece bottomed out on top of the strips wooden. You will then screw in your pocket hole screws.
7. Flip the box over, and you will now have the table top set to a depth where the panel is the perfect height. With the strips on top, the acrylic sits flush with the sides of the tabletop.
8. Now clamp the strips to the side of the table, and screw them in from underneath.
Step 3: Cut Out the Gears
There are several ways to make gears, and there are some amazing tools out there at your disposal. If you do some searching of "plywood gears," some great information pops up, including a gear template generator which I did not use (but probably should have). My templates were made by me flying by the seat of my pants and using basic gear equations. Nothing too fancy. Thus, my gears are a bit louder and a bit harder to move.
...but here is how I did it.
I designed all of the gears myself, using 3D CAD software called Onshape. It's awesome and free. I have attached the PDF of the gears. You can print these out and cut the same gear out yourself. Please be aware of scaling on the printer. Sometimes the gear will come out smaller or larger depending on the printer settings.
1. Print your gear drawings
2. Cut the paper close to shape.
3. Using some of that extra plywood, cut out a some pieces that are a bit bigger than the gear you want to make.
4. Glue (or tape, but glue is better) the paper gear onto the wood.
5. Use your scroll saw to trace the line of the gear and cut it out.
6. Using a drill (much better if you have a drill press) and a 1" spade bit, drill a hole in the center of the gear. It may be easier to drill this hole prior to cutting out the gear, but since I didn't have glue, it just ripped my template off, so I did this step last.
7. Sand the gear. You can even sand off the template/glue. You may also want to file some rough parts of the teeth with a file.
8. Repeat this process for every single gear you want to make!
Now, we have the gears. Awesome! Now these gears don't work well at 90 degrees. We're going to need to build some bevel gears!
Step 4: Cutting a Bevel Gear
I wanted to make my table completely mechanically driven, so I did not use electric motors or anything. I thought it would be cool if a hand crank powered the whole thing. This would require two of the gears to mesh at 90 degrees. The only way I could get this to work, was to bevel the gears. Here is how I beveled the gears.
1. Take a piece of plywood that is close to the size of your scroll saw table and feed it through.
2. Take a piece of scrap wood, and place it underneath on of the sides of the scroll saw. Clamp down on the plywood piece. This creates a tilt that you can use as your table to create the bevels.
3. Cut ONLY ONE SIDE of each tooth only so that the bevel only goes inward.
4. Switch the angle to the other side of the saw, but removing the wood piece and clamping it on the other side.
5. You will want to cut ONLY the opposite side of each tooth.
6. Remove plywood from the saw and cut everything else out normally.
7. You should be left with a bevel on the gear.
8. Make a small test rig to check that everything rotates okay.
Now let's assemble this crank shaft!
Step 5: Cut and Assemble the Crank Mechanism
1. Cut out the crank body on the scroll saw from the attached template. Use a drill to drill the holes in the proper locations.
2. Drill three 1" holes 1.125" away from the inside strip of the table top. You will want this to be centered. See the photo.
3. Using a jigsaw, cut the slot out to the size of the gear (about 4" x 1" rectangle).
4. Cut two 4" squares and screw them into the area where the shaft is going to go.
5. Place the beveled gears into the locations where they will mesh well. (it may be wise to test this out on a couple of scrap pieces to make sure they're placement will work.) Mark the location of the vertical gear by drawing a circle on the inside of the gear.
6. Drill a 1" hole through the table and square pieces.
7. Remove the 2nd 4x4 square and place it on the opposite side. Screw it in.
8. Insert the dowel through the drilled hole. Place the beveled gear on the dowel. Push it through until it is on the other side.
9. Mark and drill a hole on the table top where the upper gear will be placed. Insert a cut dowel and the gear.
10. Drill the 1" hole through the backside of the table so that the dowel goes completely through. Cut out a spacer and insert it onto the dowel. Drive a screw through it so that it locks the dowel in place.
11. The crank handle consists of a 3/8" dowel and a 1" dowel. Drill a hole through the center of a 1" dowel. Cut the dowel to size and glue the 3/8" pin into the 1" dowel. Then stick that into the 3/8" hole on the crank body. Place another 1" dowel with a 3/8" hole onto the back size. Glue this into place.
12. Rotate the gears and make sure everything feels good and rotates smoothly. If there are issues, you may need to file down the teeth until you get a smooth rotation.
Step 6: Attach Gears to Table Top
Place all the gears you want to use inside the table. Get a rough idea of where you want the gears to be placed.
1. Start with a gear that is going to mesh with the bevel gear. Mark the center of the gear by circling the inside circle. Then drill a hole in the center of the marked circle.
2. Place the gear and dowel inside the hole.
3. Place the next gear to where it will mesh well (it's better to be a little loose than really tight, but not too loose). Mark a circle on the table top, outlining the gear center. Then drill the hole through the center. Place the dowel. Place the gear. Make sure it rotates.
5. If the gear has issues rotating, you may need to file the teeth in certain areas to get it just right.
6. Repeat steps 4 and 5 until your gear train is complete.
Step 7: Make the Legs
Using my circular saw, I cut out some 24" tapered legs. I didn't want the table to be very tall, as I envision it sitting next to a couch. To do this, I used a 24" x 24" piece of plywood (remember all those leftovers from that sheet).
1. I measure 3" from the outside on the far end. I measured 1" from the outside on the other end.
2. I placed my ripping jig onto each point that I measured and clamped.
3. I used my circular saw to make the cut.
4. I placed the cut out piece onto the remaining piece, and marked a straight line following the edge.
5. I then used my circular saw to make that cut.
6. I repeated these steps one more time until I had 4 sets of legs.
7. Insert the legs into the bottom of the tabletop and screw them in from the inside.
Step 8: Finish It
Notice that we did not glue any of the dowels or gears into the table yet. Let's take all of the gears out and finish them with whatever stain/finish you'd like. I chose to finish the gears and crank with a dark walnut stain. I think it'd look good to have it contrasting from a lighter cherry stain. It's sealed with polyurethane. So here is my order of operations.
1. Sand any uneven surfaces with a low grit sand paper to get it all even (80 to 120 grit).
2. Iron on edge banding to any exposed plywood edges. This covers them up and makes everything look nice.
3. Sand everything with 120 grit, then again with 220 grit sand paper.
4. Remove all of the gears for staining/finishing.
5. Stain all surfaces with a stain of your choice. (I would avoid using paint, as it may add friction to the surfaces that the gears are touching). The gears are stained with dark walnut. The table is stained with cherry.
6. Apply a finish of your choice. I just used spray lacquer. I applied 2 coats.
7. If gears are tight, apply some wax to the gears and their surfaces. Mine were fine, but this could help everything run a bit smoother.
8. Peel back the plastic off of the acrylic sheet.
9. Place the sheet on top of the table
10. Enjoy your sweet new gear end table!