This post is written by Santiago Gonzales, the winner of the November MakerSpace Mini Grant.
I have designed and created a 3D printed skateboard mold that would enable multiple skateboard decks to be built for a fraction of a single skateboard deck cost!
The idea came about after I started skateboarding for the first time in my life to cut down my commute time to school from my apartment. I really enjoyed skateboarding, and being an engineering student, I started to browse online to see if there was a way for me to make my own board.
To my surprise, I found no common way for people to make skateboards on the internet. You could buy concrete molds made by other amateurs, or buy one of the few products online to make your own board like a vacuum seal or a foam mold that you have to carve into with a tool. None of these possibilities were cheap or professional. So, I decided the best way to make a professional board was to design a mold on CAD, 3D print it, laser cut wood veneers, and press it.
The only reason my project was possible was thanks to the tools available to me at the Makerspace. I used the Elite and Fortus 3D printers, and the laser cutters.
The materials that I used were :
The most time-consuming step is to design the mold in a CAD program and 3D print it. My initial design was a mold for a board that would be 31.8 x 8 inches, which is the standard skateboard. However, due to the size, printing on the 3D printers would have cost a ridiculous amount, and taken over a week to print, so I had to redesign my mold.
I ended up basing my design off the 22 inch Penny board, but extended mine to 23.8 inches. So the board itself will be 23.8 inches long by 6 inches wide. The mold will be those dimensions plus about 2-4 inches in height, depending on the section of the mold.
The drawing shown below was the only one I could fine for a skateboard, so this is what I used to design my mold. I had to alter it a little after deciding to do a smaller board.
The CAD program that I used was Inventor. The first thing to do in Inventor, is to create the general side view outline of a skateboard on the Y-Z 2D-Plane. I found it useful to first do the calculations on a piece of paper for what angle you want your skateboard ends to be.
The figure below shows the side view of the board. I extended the outline into a box so that the sweep gives me a rectangular prism.
The next step is to create the dip of your board in the Y-X 2D plane. To make the most accurate dip possible, I created a line using the Parameterization line tool.
The figure below shows the parameterized dip line to sweep.
Now, you can sweep the side line along the parameterized curve to create your bottom mold. After the sweep you create planes and move your board so that you can cut the mold into three equal pieces as shown in the figure below.
Now that the mold has been cut, convert into an STL file and it’s ready to print. The same process is done for the top mold, except make sure that the top is an inverse of the bottom (making sure that your back-end bend goes upward so that the bottom and top pieces fit like a puzzle piece).
I used the Elite and Fortus printers to 3-D print. The prints were low density to minimize the cost and print time.
A further improvement to the mold would be to include holes on the side of the molds with matching pieces sticking out of the mold to have them fit into one another like puzzle pieces. This way you do not need to glue the molds together. Since I was already maxing out the printer space, I did not do this. Instead, I duct taped the mold pieces together as shown in the figures below. As far as the mold goes, that is all you need to do.
As you can see in the figure above, the molds together create a perfect rectangular prism. The bottom mold has been duct taped together already.
The trigger clamp on the top and bottom extra pieces demonstrates how I will be applying pressure to the mold.
~Updated on 22nd January 2018~
After receiving the wood veneers, I used the large laser cutter (Epilog Fusion) at the Makerspace to cut the wood into the dimensions I wanted for the board. I decided on a unique design instead of doing the plain normal board shape as shown below.
After laser cutting, I used the wood glue and a roller to put glue evenly in between the wood veneers. It is really important to apply the wood evenly so that there is no air bubbles in between them. After the wood glue is applied, I quickly lined up the veneers with the skateboard mold and applied the trigger clamps as evenly as possible throughout the mold. Once they were all lined up I pressed them as much as possible. Due to the low pressure that is applied from the trigger clamps, I left the board pressing for a little longer than a day to ensure that the board would hold the shape of the mold.
The figure above shows the boards being pressed under the mold with the trigger clamps.
The figure above shows the side view of the board after pressing. You can see that the board held the mold curves well.
As you can see from the above figure, the board after being pressed held together well. You can see that the wood veneers did not overlap perfectly, so the next step is to fix the edges.
The board press morphed the wood into the shape I wanted, and now I only need to do some finishing touches on the board. The veneers didn’t align perfectly, so I am going to have to polish the edge to make them smooth with a router or with a lot of sanding. After I smooth out the board, I clean it and finally seal it with a gloss wood finish.The only thing left after that is to paint the board, apply grip tape, drill the holes, and put on the trucks, bearings, and the wheels. The main step to make the skateboard deck is finished.
It took a lot of trial and error to create the mold since the only knowledge of CAD I had was from EG1003. I had to make a ton of Inventor files with many different designs until I finally got it right.
A possible improvement would be to some way line up the wood veneers better with the mold for pressing so that the edges come out smoother. In the end, it will all be worth it when I take my first ride on a skateboard I made from scratch myself (hoping it doesn’t break right away).