Introduction: DIY Air Hockey Table
You can download a 3D model of the DIY Air Hockey Table here. This will help you understand the project better. In order to view the 3D model you need to install the free application SketchUp.
We hope this information is useful to you and start building this thing straight away!
If you've got any questions or remarks or you just appreciate this instructable, don't hesitate to comment!
Step 1: Requirements and Measurements
COMPONENTS (MEASUREMENTS ARE EXPRESSED IN MM)
Some of these measurements are standard european measurements. So if you are American these might vary a little. This means that you cannot make an exact copy of this project and need adjust the project to the materials available to you.
The drawings might clarify what materials you'll need. They show the basic construction and measurements.
Construction frame (of whitewood)
- Two long sides: L=2530 ; W=45 ; H=70 (no. 1, see this component in the drawings)
- Two short sides: L=1310 ; W=45 ; H=70 (no. 2)
- Two long sides: L=2440 ; W=20 ; H=35 (no. 3)
- Two short sides: L=1220 ; W=20 ; H=35 (no. 4)
Expenses: 27 euros (about $37,-)
Playing surface (of MDF)
- L=2440 ; W=1220 ; H=6 (no. 5)
Expenses: 13 euros (about $18,-)
- Small beams of scrap wood with heigth of 35mm (no. 6)
Expenses: 8 euros (about $11,-)
Plate opposite to the surface (of chipboard)
- L=2440 ; W=1220 ; H=12 (no. 7)
Expenses: 11 euros (about $15,-)
- Leaf blower, centrifugal blower or vacuum cleaner (no. 8)
How to calculate the the required volume flow and pressure rise: see attached PDF file below (I'm not sure if the specified jet speed is correct, though).
The required output for a 7 to 8 feet air hockey table is about 400 cubic feet per minute. Regular household vacuum cleaners have an average air output of around 140 CFM. You'd need at least 3 vacuum cleaners to make the puck float. This air source would therefore be to expensive. There are more powerful industrial vacuum cleaners, but are hard to get and expensive. Centrifugal blowers are highly specialized. The output ranges from a few CFM to a 1000 CFM or more. These blowers are used in air hockey tables as well. You might want to try to get one for cheap. Overall centrifugal motors are pretty expensive.
Leaf blowers are very powerful. Their output ranges from 350 CFM to 600 CFM. We believe that getting a cheap second-hand electric leaf blower is the best option. We therefore bought a new leaf blower with adjustable output (max. output: 490 CFM). We tried out the leaf blower at the lowest speed (7000 rpm) and it worked fine. The noise produced was significantly less than at higher speeds. It should have a circular outlet. The blower cost 40 euros (about $56,-).
- One or two meters of tube with a diameter of about 90mm (depends on size of leaf blower outlet)
- A sheet of PVC measuring 250mm by 250mm, with hole in which the tube fits. (no. 9)
- If the tube doesn't directly fit into the hole, use a PVC muff (which does fit around the tube and in the hole)
- Two pieces of plywood measuring 250mm by 250mm (no. 10 and 11)
- Wooden beams with a length of about 400mm
- Strong piece of fabric measuring 400mm by 400mm
Puck and Mallets
Note: these are the tools we used, but you might find that other tools can be used for the same job as well.
- Proper tenon saw
- Regular saw
- Hole saw
- Wood glue (regular and polyurethane glue)
- Drill with adequate drillbits
- Dremel with adequate drillbits of 1mm (or 1/32)
- Sanding machine with very fine and super fine sandpaper (P180 and P1200)
- Hammer and suitable nails
- Screwdrivers and suitable screws
- Thermoplastic adhesive (hot glue)
- Duct tape
Step 2: Building Frame
A: In order to build the framework you need to have a proper tenon saw. The 8 different pieces all need a 45-degree-angle end. Extreme accuracy is required to make the corners fit into each other. We didn't want this project end in a complete disaster, so let a lumberyard do this for us ($18 extra). If you do have the right tools, you should just make sure you saw them to the right measurements.
B: If you've got your beams (no. 1, 2, 3 and 4) ready, lay the chipboard onto the floor. Then check whether all sizes are correct by putting the beams down to their positions on or against the chipboard. It is important that the floor you're working on is flat.
C: By using some nails and construction (polyurethane) glue, attach the four smaller beams (no. 3 and 4) to the corresponding bigger ones (no. 1 and 2). The smaller beams should be glued at the right height. So the chipboard fits into the ridge.
D: Glue the four sides together, wrap a strap around the framework and tighten it. The chipboard should still be in the center of the construction. Leave the glue to harden for at least 4 hours.
E: Predrill all four corners and screw screws in them (see the image below)
Step 3: Drilling Holes / Preparing Playing Surface
F: Before drilling holes, you'll need to make a grid on the MDF. You can either mark the 25mm squares (1 inch squares) you self with a ruler. But if you get sick of measuring you could use the grid template provided on the bottom of the page. Then draw a bigger grid, in which the templates fit. Simply stick the template to the surface.
G: Drill the holes according to the grid you've just created. Use a dremel and drillbits with a diameter of 1mm (or 1/32 inch) to do the drilling. This job is time consuming, but do not rush. Otherwise you'll break a lot of drill bits.
In total we drilled 96x48=4608 holes, breaking 3 drill bits.
H: Use a sanding machine to remove the burrs on the other side of the sheet. This side will become your playing surface. First sand the surface down with rough paper. Then smoothen it further with fine sand paper. Make sure that the holes are free from waste.
Step 4: Attaching Pillars to Surface
I: Saw about 150 to 200 wooden pillars with a height of 35mm. We've tested whether the supports were strong enough (no glue was involved yet). If you can stand on the surface without breaking it, you should be on the right track : )
J: We placed the pillars 3 'squares' (75mm or 3 inch) away from the edges and 4 squares separated from each other. Amount of supports used: 9x19-2=169. But you can experiment with this pattern yourself. In the middle we left out 2 supports to make sure that the air inlet would fit in. Edit: Air inlet fits in without removing any pillars, and air inlet will be made in a corner of the table.
K: With NON-polyurethane glue (regular white wood glue) fix the supportive pillars to the non-smoothened side of the MDF. If you would use polyurethane glue the pieces of wood would be slightly lifted or displaced. Put the chipboard onto the pillars to ensure that the pillars stay in the right place while the glue is hardening.
Step 5: Attaching Surface to Rest of Construction
L: Cover the holes near the edge of the fiber board with tape (on the side of the supports of course). This prevents the holes from being clogged with polyurethane glue.
M: Then put the glue on the edges and slide the board into the frame with the supports pointing down. Remember to put the surface in the corresponding side of the frame! Image M might clarify this. The chipboard should also be already in place, but not be glued yet. This will keep the surface straight.
N: Finally hammer 5 nails through the short sides and 10 nails through the long sides of the MDF into beams number 3 and 4.
Step 6: Making Air Inlet / Attaching Leaf Blower
We decided to connect the leaf blower with a tube to the table, instead of directly mounting it onto the table. Since vibration might cause this machine to fall, if it would be mounted directly to the table. The image below shows the leaf blower we chose. Most of these tubes are expensive. We didn't want to spend to much money on this, so took a suitable tube from a construction site. You'll need to experiment with the size of the tube yourself, because it is dependent on the air outlet of the leaf blower and the one we used isn't ideal.
Chipboard is cheap, but has as disadvantage: it is weak. In order to make a sturdy air inlet, the force needs to be distributed. This is why you'll need a large PVC sheet (with a hole in it), which covers a large area. We needed a muff to make the tube and PVC sheet fit tightly.
O: Glue the muff onto the blue tube with thermoplastic adhesive. Connect the other end of the tube to the outlet of the leaf blower with some duct tape. This will allow you to easily remove the leaf blower and use it to clean up your back yard.
P: Using a 'drill-saw' (see image P), drill holes through the two layers of plywood. The holes need to be bigger than the one in the PVC sheet, since this sheet will be sandwiched between the plywood. Now decide where you want to have the air inlet (we recommend you to place it in a corner of the bottom plate). Once you know the position of the air inlet, drill a hole through the chipboard (bottom).
Q: Predrill the two layers of plywood according to the diagram: one piece of plywood should have four holes in each corner, the second one should have eight equally distributed holes. The same applies to the PVC sheet.
R: With polyurethane glue, glue the layer of plywood (with four holes) onto the desired place on the chipboard. And screw the plywood down with four screws. Now put the PVC sheet and the second piece of plywood on top of the plywood you just glued. Make sure the holes of the two components are aligned and screw them down with eight screws.
Step 7: Attaching Chipboard to Rest of Construction
S: Remove the the tape, clear holes from glue and other waste and clean the rest of the 'air chamber'. Remember: you won't be able to reach this section once you've glued everything together!
T: Put regular wood glue on every single pillar. And put polyurethane glue on the edges of the framework. Gently lower the chipboard and slide it into the frame work. Put some weight on the playing surface and leave the glue to dry.
Step 8: Making Goals and Finishing Off
U: Drill 15 cm away from the middle of the short side two holes into the framework, so the playing surface remains unharmed.
V: With a jigsaw you can easily cut between these holes at the height of the playing surface. Remove the beam you've just cut out of the frame.
W: Sand the 30cm-long cut away down, so the transition from MDF to whitewood is smooth
X: Nail down two 40cm long beams above and under the cut away with a strong fabric in between. By doing this, you create a kind of sack around the goal with openings on the sides, so you can easily grab the puck out of the sack if someone has scored.
You should repeat this process on the other short side.
-Adding aluminium or plastic bounce off strips will maintain the speed of the puck better.
-Add a centerline and additional circles, depending on what game you play.
If you've executed these steps correctly you should be done. Switch on the leaf blower and start playing!