Miniature Air Hockey Table - Crafted From Wood

Hello everyone, I am Lorik Asani and I am joined by my partner Daniel Belyayev. Very recently we were tasked by our school staff to create something beneficial to our school community as part of a summer program. We thought about it for a bit and eventually thought of something to add to our cafeteria, being as it is a little on the old side and would really make the most of something new and exciting.

We settled on creating a sort of "game-room" (Or game corner rather), that included a few miniature versions of some fan favorite games (Ping Pong, Billiards, etc.) The first game that we decided to make was an air hockey table, as it's one of our favorite games to play together and would be a really charming project to make out of wood. If you follow along, you will see the process of how we made the table, step by step, along with any challenges and pieces of advice we would give to someone trying to make a miniature air hockey table for themselves. The following is the culmination of our work!

Software:

• AutoDesk Inventor
• AutoCad
• LightBurn

Printing Machine:

• Laser Cutter
• 3D Printer

Materials:

• 6 24"x12" Wood Planks
• PLA Filament
• 3x PC Fans (WDERAIR EC Axial 3 Inch Muffin Cooling Fan)
• Tape (Preferably Electric)
• Silicon Dispenser

To begin the process of making the air hockey table, we first had to think about the logistics of it. We didn't just want to dive head first into the task while not knowing the dimensions or capabilities of anything. The very first order of action was going to be the size of the table. Due to the availability of resources that we had access to, we decided that we were going to make the table miniature, not only to preserve the limited wood that We had, but also to allow for portability and convenience of travel/play. Once we had this realization, we took to the pile of wood we had and looked around for a board that we felt would be a perfect medium of too small or too big. We stumbled upon a few 20" x 12" boards, and felt that it would be a great size for comfortable play, but not so big that it defeats the purpose of a mini air-hockey table.

Next was to think about how tall I'd want the table to be. In this step, we had to keep in mind that on the bottom of the table needed to be a fan and an air chamber. In playing around and thinking about this height, we settled on 5.5 inches as it means it would be low enough to be stable when placed on a table, but tall enough to be played comfortably.

Final step in this process was to figure out how big and spaced apart the holes in the table would be. Upon finding an online physics forum, we found some calculations about the needed dimensions and psi of an air hockey table if the holes were 1/16" in diameter. There is a lot of information discussed on the forum so we won't break down everything (I will attach it below however), but the main takeaway is that the holes will be 1/16 of an inch in diameter spread out by a space of 1 inch both vertically and horizontally. With these basic ideas in the our head, we felt that we were ready to start tackling actually making the table, which would require some tweaks/trouble shooting later on.

Physics Forum (Click)

The plan from the very start of the whole process was to design the walls and floors of the table in AutoCad, and then laser cut them out and assemble, sort of like a big puzzle. That is ultimately the route we took yes, but before ever opening AutoCad we first modeled what we wanted the whole table to look like in Inventor. The reason for this is that before actually going through with printing everything, we wanted to sort of visualize how all the pieces would fit in with one another. In the attached photos of the final air hockey model, you will be able to see the following:

• The dimensions of the horizontal walls
• The dimensions of the vertical walls
• Distance between both parallel planes (Which makes the air chamber)
• An overall look of the desired finished product

The process of making this model was rather simple, just simple sketching and extruding. Being as the table is such a boxy surface with literally no curves other than the deposit, to 3D model your own would just require that you type your dimensions to your wants and needs. For us, as we are working in a 20x12 limit that is 5 inches tall, we made sure all sketches fit within this size. From there, you just need to make all the walls and floors to your needed thickness (Which in our case is 1/8" as that's the thickness of the wood) and you're golden. Now we can begin designing the cuts.

To get all the pieces needed ready in AutoCad, start by opening up a brand new file. In this file you will need to create the following:

• Two 20 x 12 Rectangles
• Two 20 x 5.5 Rectangles
• Two 12 x 5.5 Rectangles

In total you should have 6 uncut rectangles in AutoCad right now. These 6 pieces once cut will be perfect frame for our air hockey table. The two biggest rectangles will be used as the platforms for the actual tabletop and air chamber respectively, the 20 x 5.5 ones will be the side walls the long way and the 12 x 5.5 will also be walls just for the shorter side.

Something crucial here are the holes and little teeth you see on the boards themselves. The purpose of these 2 creations are to provide the mechanism that will be used to connect the boards together. Both the height of the teeth and size of the holes will be 1/8", meaning that it will be a seamless fit as that's the thickness of the wood as well. To make these teeth, we first had to settle on how many we wanted. We felt that 4 on the long side and 2 on the short side was appropriate. Next we sectioned off both sides into 4 equal quadrants and 2 equal halves respectively, to make sure each tooth was spaced apart exactly the same. Lastly in those sections, we went up 1/8 and moved 1.5 units to both the left and right, to make sure that the tooth was 3 inches long. We did this in every section in both the long-side and short-side and finally mirrored over both to create the final piece. (A little extra thing we had to do was scale down this plank and every other one as well by a factor of 0.953, so that it was a little smaller than the actual wood we were cutting. This is done to make sure the board is only cut within its boundaries, and not outside.

To then make the holes, we took the same 3 inch by 1/8 inch sizing that we used for the teeth but moved it over to the side walls, which are noticeably smaller than the platforms. We went down 1.5 inches and over 1.4082 before placing to make sure the tabletop wouldn't rest completely at the top and would have small walls for the puck to bounce around in, and so that the pegs/teeth fit perfectly together.

Next up was making the big goal hole for the puck to go through when someone scores. This was easy enough as all we had to do was place a large rectangle above the peg holes, which would then be sanded down from said hole to make sure that there was no barrier stopping the puck from going through.

The last little step we had to accomplish was making a large circular hole in the bottom of the chamber to allow a fan to blow through it. This again was easy enough as we just needed to find the diameter of the fan we intended to attach and place a hole the same size. To know which fan this would be, we went back to the physics forum and looked at the classifications of fan needed, and went on amazon and found one. We used this fan for the process, while still being ready to pivot and find another

What we feel is the coolest and most satisfying part of the job has just arrived; the time when we can laser cut all the wood with the designs that we created prior. Fortunately, we are lucky enough to have a Thunder Laser Nova 35 Laser Cutter present at our workstation and therefore have an awesome tool to work with. We understand that not everyone has quick access to a machine like this, so some work arounds include finding your nearest laser cutting service and asking them to do so. Alternatively, if you have some heavy duty machines to yourself, some skill and a lot of patience, cut it out yourself.

If you choose the personal laser cutting route like how we did, import an AutoCad DXF File into LightBurn, the software that the Nova 35 runs on. Once this is imported, you will drag the piece you want to cut into the designated station in LightBurn, which will tell the machine that whatever is in it is what needs to be cut. You also have to make sure that the colors and framing is right in both the software and machine, as each setting has different properties and qualities. It is a lot to try to explain over writing and a visual guide is a lot more helpful, so you find a really helpful one right HERE.

Once you have the hand of how to work the machine, load your wood into the machine (Mine is 24x12 and 1/8" thick). If your framing is right, you can begin the cut. Both the playing top and air chamber are basically the size of the board itself, so they will require a full one to work with. The walls however are only 5.5" tall, meaning if you used a shared line on AutoCad (Ones bottom is the others top), you can print each of the respective ones with a single sheet. In the end, you should have 6 pieces of cut wood, whose teeth fit perfectly in the designated holes.

In case you wanted to see how it looks for the laser cutter to work, you can look at the attached video. Once the file is uploaded and framed correctly, the machine does a really amazing job at precisely cutting out everything you modeled. Check it out for yourself!

While we already knew the dimensions of the fan we were going to use for this project, we didn't know exactly how strong this fan needed to be. It is because of this that the "Hunt For The Fan" starts. This quest involved a lot of talking to teachers and people asking around for spare parts and any advice. Our original thought was to take apart a spare PC from a computer science class and use an old PC fan, by soldering the wires and attached to a volt battery. However we are no electricians so this wasn't going to be any old easy task. Nevertheless, we did exactly that, and began dismantling 2 PC's and extracted two different fans:

• A Pano-Mounts Black High Performance Cooling Fan
• An LED Antec 3 PC Fan

Both fans were roughly the same size but had varying levels of strength, and to be fair we didn't know what those strengths were being as they were old and in a PC, meaning they had been worn down and not at top efficiency and quality. This is where the idea to solder comes into play, as if we can power these fans with a volt battery we can then test and see their power.

When it came to soldering however, we couldn't find an available 12 Volt battery (Which is what would've powered the fans) anywhere in the building, meaning we had to find something else out. We went onto Amazon and bought a few different computer fans that were of the same size, but settled on an easy to use, an WDERAIR EC Axial 3 Inch Muffin Cooling Fan. Once the fan came in, we brought it over to the workspace and was ready to give it a shot.

Using the large hole and 4 smaller holes in the corner, we were able to attach the fan onto the bottom plank that will be used to create an air chamber. Because we had all the dimensions of the fan, its outer casing and positioning of the nuts and bolts, everything was an easy fit (Except for us putting the mini holes 45 degrees rotated wrongly the first time, which it an easy thing to avoid). We lined up the fan with all the holes in the correct spots, slipped the bolts through and on the other side twisted the nuts all the way up until the fan was secure. Just like that the fan was attached and all wood components were accounted for

Moving on from laser cutting to 3D Printing, we have 3 things that we need make that will not be out of wood:

• The Puck
• 2 Paddles
• 2 Goal Deposits

To model these we went back into Inventor, as Inventor is compatible with a 3D Printer. To start we made 2 different sizes of pucks, one rather thick and one quite thin. Making the puck was another easy process. We first made a circle 2.5 inches in diameter, and in 2 separate files extruded up by .5 an inch and .2 and inch respectively. After that we simply filleted the puck on the top and bottom edge by a factor of .5, meaning that it had a nice roundness after all is said and done.

The paddles were next up and it was another rather easy process. We first created a circle that was 3 inches in diameter and extruded up by very little, 0.25 inches. We now had another puck looking thing but on the top surface of that, sketched and extruded another cylinder up. Then on this handle, we started a sketch from a vertical midplane of the up-most cylinder, and drew a quarter circle that was half the diameter of the cylinder, and revolved it around the side l-ine of the quarter to create a full semi circle. This was the handle done. The last little step of the paddle involves making the upwards lip thing. To create this, we started another sketch on the outermost ring of the paddle and extruded up a tiny square. On this square, we re-sketched on its outside surface the same shape and revolved it around the central axis of the paddle, making a nice extruded ring on the outside of the paddle. We filleted the edge of this ring again to make it smoother and the paddle was done.

The last thing we made was the goal deposits for the puck to go into. To make these, we measured out the length of the goal itself and made a rectangle that had the exact same dimensions, extruded out 4 inches to give a big enough frame to house the puck when scored. From this rectangle, we filleted the butt-end to make it rounded. Lastly, we created a shell to actually have a space for the puck to go. Once this was done, we printed them out.

I printed all these models using PLA Plastic off of an Original Prusa MK4 3D Printer kit. The resulting pucks and paddles were very nice and similar to the 3D models we made of them in Inventor, and will act really well with the rest of the table. These are the last physical aspects that are needed to be printed.

In case you wanted to see how it looks for the 3D Printer to work, you can look at the attached video. Once the file is uploaded its really cool to see your work come to life!

In order to make the surface of both the wood tabletop and the puck smoother, we sanded down both surfaces. The thing we used to sand down both the wood and the PLA for the table and the puck/paddles respectively was a spongy rough thing that was a pretty high grain, in order to make it as smooth as possible. There isn't really much to say in this instance, the only advice I'd have for you is to use the highest grain of sanding equipment you can get, whether it be a piece of sandpaper or a sponge sander like how we used. There will be a lot of loose dust in the air when you do this, so be mindful of that and make sure you do it somewhere where there is decent ventilation. There isn't any exact amount of time you need to sand for, just until you run your and over and it is smooth!

With all of our pieces cut out, and our game pieces printed, it was finally time to assemble and test out the table and see how it worked. To begin we put the long wall pieces into the playing board, by connecting the boards longways with their respective pegs. I first put the top board and followed it up by putting the bottom board on after, to create a structure with a hollow width but walls covering the length of the two boards. Next up I attached the 2 "goal-walls" to completely close up the structure and make the finished 1st hand assembly.

FIRST TEST:

With the model put together, I finally felt it was time to turn on the fan and see if the table would work. I plugged the cord into the outlet and turned on the switch to allow the fan to start. The fan started blowing as expected, so I placed both pucks on the surface, and to our dismay neither of them glided across the board. I was fully expecting at least one of the pucks to work and start sliding across the board, but not one of them did. It was at this moment I took a step back to try to analyze the reason for the failure, and as I ran my hand across the board I figured it out; the air pressure was too low. The push of the air out the holes was very small, and I could tell it was no where near as powerful as I needed it to be. I went back to the drawing board and came up with a few possible solutions.

Despite all seeming well, its very rare that when you make something as complex as this that it goes right on the first attempt. In our case, the fan didn't provide enough pressure through the holes to lift the puck up over a sheet of air. To fix this we decided to try to increase the amount of air strength/pressure and had a few ideas;

1) Make the holes smaller and closer together to allow for more air to be on the puck at all times. With the dimensions we had the holes at (1/16" and an inch of distance in between) there was very rarely more than 1 hole applying air to the puck at a time. Not only were the holes too big that the air wasn't concentrated enough, there weren't enough of them so that there was a constant blow of air on the puck at all times. To resolve this issue we changed the holes to 1/32" (Half as big) and brought them 1/2" apart from one another. In addition to that, we also increased the amount of holes there were so more air would be dispersed across the board. we went from a 22x11 array (242 holes) to a 45x22 array (990) holes. That's more than 4 times the amount of holes occupying the same area as before, meaning the air will be more spread out on the puck yet not any weaker.

2) In addition to the idea that the holes weren't allowing for the air to lift and carry the puck, there is also a large possibility that the fans just weren't strong enough to do so in the first place. To try to mitigate this issue, we ordered 2 more of the same fans to triple the air output we had earlier, hopefully allowing the game to play more smoothly than before.

Of course, all of these changes mentioned were reflected in the CAD files that we edited, we redid the array of holes for the tabletop and changed the 1 hole to hold the fan to 3 holes, as to hold the 2 new ones that we ordered. We re-cut these pieces once again and got ready to assemble the air hockey table once more.

Your table may act differently than our table did, meaning you should be responsive to your specific case and take it from there; what happened with us may not happen to you meaning doing what we did isn't a guaranteed success. It took us a few tries to find the right combination of changes, but we just decided to highlight the final one as it was a process of trial and error, and wouldn't be too interesting to go over every single change until we found the right one.

With all the changes applied to the board, it was time to assemble the board one more time. With a better distribution and array of holes, and 3x the fan power, we were really amped to try the board out once again. We repeated the process of plugging the pegs into their assigned holes with every wall and after it was all set up, turned on the fans once. This time the puck was gliding much better than before, as the air was strong enough and there was enough of a distribution of it to cover the puck a lot more, especially compared to the first go. The table wasn't perfect as the puck didn't bounce all too much off of the walls, but still a very nice and rather successful attempt at the table.

Next up we attached the goal deposits to the goal openings. We did this by simply super gluing the corresponding opening with the goal holes and pressing tight until the glue hardened. We then cut out some right triangles out of wood that measured 3.5" by 3.5" (The smaller sides, not the hypotenuse), that we used as support and glued onto the underside and wall of the table. Once both goals hardened, the build was done.

The only thing that had to be done now was to seal up any open spaces left in the final assembly of the board. This includes any spare space in the teeth, the corners where the walls meet and any miscellaneous space where air could possibly leak through. To cover these we resorted to using silicon, as its easy to administer and will cover up any holes completely air tight.

Watch the game in action! (I apologize for the poor quality)

CLICK HERE TO WATCH ON YOUTUBE

This air hockey table taught us a lot about the engineering process, as due to the constant failure faced. During a project, I've never before had to redesign what I was doing so many times, from the board to the pucks to the fan and more. Not only was the experience very humbling, it was also extremely beneficial to us as we got more acclimated with what a real world project may be. Of course, if we ever have to build an air hockey table again we have gained insight into how to do that, but our experience goes so much deeper than that. We dedicated a lot of time and effort into making something we thought would be cool and rewarding, and on our first few goes at it it didn't end up working for us. Rather than just calling it quits however, we kept at it and tried different ideas until we got it right, like how real industry professionals do.

In addition to the valuable skills and lessons learned and gained during this project, it was also just a really fun and engaging experience. Seeing our idea go from paper to computer to real life, entirely made of the wood we had in our workshop was very fulfilling to us. My partner and I had very little experience, if at all, actually making a physical prototype of some of the work we had sketched up. This was the first real attempt at making a diorama of sorts, and while it took a few tries to get right, our persistence let us truly create something we are proud of.

To everyone who took the time out of their day to read this Instructable, we'd like to extend a warm welcome to you. Hopefully you enjoyed seeing the ideas of the table culminate into the physical model, and maybe you even got inspired to make some wood-work of your own. Whether it be a miniature air hockey table like you see here (Which isn't a bad idea), or something completely original, it would be amazing if our Instructable was the catalyst for YOU to get out there and make something special. With warm regards,

- Lorik And Danny