The DIY-Series: The Press
Updated: Feb 27, 2019
It’s finally here! The blog post where we discuss building your own press at home. This is definitely a long part so grab a cup of tea, bare with us and hopefully you’ll find it interesting.
The First Press
Our first press was the absolute basics. You'll need: sheet MDF cut into planks (longer than the length of your board), wood glue, jig saw, sanding paper & some sort of foam (we used insulation foam from the DIY shop). The general idea is to create a top and bottom mould that will shape your snowboard camber profile when clamped together.
To create your moulds:
1. Cut your board shape (camber profile, tip and tail) on an MDF plank (see picture below *note we made this for a PowDaze so yours would be twice the length), this gives the top and bottom mould template. The camber profile can be as easy as picking your favourite board and tracing the camber onto the MDF.
2. Now copy this shape onto all of your MDF planks and cut each plank using a jigsaw. You'll need enough MDF planks to cover the width of your board and more. If you have a router then use a template cutting bit to trim all the MDF planks to the exact same shape as your mould template. If you don't have a router then don't worry, you'll just have to do more sanding later on.
3. Glue all the bottom mould sheets together and all the top mould sheets together; this will give you the complete set of moulds. After the glue is dried take some sand paper and smooth everything out.
5. Add some handles to provide some easy manoeuvring, as the top & bottom moulds are heavy.
To use the press, we put the bottom mould onto a small workshop bench, lay up the snowboard materials (blog post about that here), put the top mould on top and clamp it all together. As we were in a cold garage we attempted to create a low heat environment with some old tarp and electric heater to make sure the resin cured fully.
After proving our concept, it was time to upgrade out press setup to a pneumatic (air powered), heated press that will apply loads more pressure to the board and allow a quicker cure time for our resin system. To really get professional quality boards, you will need to step up your system to something similar.
The pneumatic press is made up of: a metal frame, top and bottom moulds, steel sheets, an air bladder, a cat track, 2 heat blankets sandwiched in aluminium sheets and more aluminium sheets to sandwich your layup; we covered why these parts are needed in the last blog post.
Research Now, where to begin with all of that? Research. We spent near to 6 months just reading and gaining knowledge about other people’s projects, pneumatic systems and well, just about everything. If you refer to our ‘DIY Series: Saviour websites’ post you’ll see a more in depth list of places to search but here are some of the really good ones:
Ski Builders Forums - read as many build journals as you can. It will give you an idea of what works and will help you avoid many headaches.
HappyMonkeySnowboards Wiki - this is a great resource as HappyMonkey had a great manufacturing setup and explain in great detail how it was built.
Signal ETT - Every Third Thursday series on YouTube follows Signal Snowboards trying out wacky builds and while it's fun to watch you can also learn a lot about how to build boards.
Design So now you have all this information and a lot of ideas next you have to start designing your press and theoretically testing your designs. As you are going to put this machine under a lot of pressure you have to make sure it’s going to have to withstand it - you don't want to build a bomb! Start by downloading a free CAD software (such as AutoCad Fusion360) and decide on a few ideas/designs you’d like to test. Luckily for us we had Ed the intern - a mechanical engineering student working on this for us! After you've got your 3D CAD model, it is important to run finite element analysis (FEA) tests on your designs as this will indicate whether it can withstand the pressure. Note, we tested several different steel frame designs using FEA. Aiming for a minimum safety factor of 3 we chose the design you see pictured at the beginning of this blog post because it showed very low stress levels and deflected less than 0.1 mm at our anticipated working pressure of 0.3 MPa.
Pencil designs of what we wanted to include:
The Frame Once we had finalised the frame design it was time to source some materials. For the frame we called around maybe 5 or 6 local engineering and steelworks firms to get quotes and settled on the best quote/all around nice people: Beckwith & Sons Engineering. These guys were a great help and we would definitely recommend them. Once the frame came we decided to finish it ourselves, which in hindsight we would never do again as it was 5 days of scrubbing with metal scrubber to remove dirt/oil, washing down with rubbing alcohol, followed by water and then finally spray-painted the whole thing to prevent rusting. After all the time and money spent on spray paint we should have just paid for the firm to do it!! Luckily we had already bought the air compressor for the air bladder system so we ended up using that to spray paint the frame.
We had 4 weeks until the frame was going to be delivered and so we wanted to get everything else sorted in that time frame so it would all come together harmoniously - spoiler alert it doesn’t. Our workshop’s electrical circuit needed a little bit of up dating so with the help of Buster, an A+ electrician, got that sorted in a couple of hours (he later makes a heroic return for our press’s electrical circuit design). RS-Online and B&Q are life savers in getting all your DIY electrical parts.
Air Bladder Our Airbladder is actually just fire hose that when pumped full of air becomes extremely rigid (we bought ours new off of Ebay). Fire hose is great as it is structurally reinforced to withstand a lot of pressure. To assemble it all together William first cut the hose to length, drilled holes for the pneumatic connections and then bolted it at each end using angle steel (which we bought at B&Q our local DIY shop). Three hoses were used in parallel to create an air bladder that applies pressure to the press. The tubing used to pump the air from the air compressor was kindly donated from a friend who also built a home ski press - but it is important that you get a pneumatic rubber tube that is thick, reinforced with fibres and is designed to be used for airflow under pressure. The hoses are connected to the air compressor using classic female/male pneumatic connectors (all bought from RS-online). You can test your connections by covering it in soapy water and pumping air through until you hit your desired pressure - if you see suds, there is a small leak and something in the connection will need tightening.
Heat Blankets & Electrical Circuits One of the hardest parts of building our own press was the design of the electrical circuit that powers the heating blankets. Since we have very little experience with electrical circuit design, we first started by asking our same friend who already built his press for a bit of guidance. This was super helpful but it was clear we would still need some help to get this done and so we asked someone who knows about circuitry: Buster. It involved many late nights of going back and forth to our different houses but in the end we did get somewhere and it looks incredibly legit. Yes the giant yellow switches were our choice. All of the parts for the circuit were purchased at rs-online (you don't want to scrimp here because electrical safety is not something you want to mess around with). The silicon heat blankets were bought off of Alibaba.com and came from China, which landed us with a pretty hefty import duty charge so be weary of that! When ordering your heat blankets make sure you get ones with thermocouples and not thermistors as the PIDs for thermistors are way more expensive than thermocouple ones. We decided to sandwich the heat blankets in aluminium for two reasons: 1. To protect the blankets from damage and 2. To ensure good thermal conduction along the length of the board - you don’t want any warpage in the board from heat stresses. We covered the edges of the aluminium sheets with electrical tape to avoid damaging the silicon blankets.
Moulds The last component of the press to be completed was the moulds. The method we went about doing this was long, messy and painful and there are definitely ways to avoid this but I’ll still tell you our story. We bought MDF from JGard & Sons (a local timber yard) and they cut it into:
The moulds are all bolted together with threaded rod, so first we had to measure and drill the bolt holes (you’ll definitely need a pillar drill for this). Each of the smaller planks had a hand drawn template, which needed to be cut to shape and sanded down. These would then create the top and bottom moulds with our designed lift. All of the planks for one part of the mould were held together by a long metal rod and bolts at each end. So whilst listening to many a podcast (we really recommend Transworld Snowboaring’s Eddie’s Wall) we spent hours drilling holes, sawing shapes and yes, this took us ages.
The first problem that occurred was even though we were extra careful when cutting all the holes and shapes, when each plank was bolted together to make the mould, they did not line up perfectly. This meant that we had to spend ages again sanding the the mould to make sure all imperfections were smoothed out. To avoid this it could be worth spending money on getting all your parts CNC cut.
The second problem is that the bottom mould had a bit of a fit problem, as in we couldn’t get it in the frame whilst held together, therefore we unassembled it and reassembled it plank by plank in the frame. To avoid this you should consider making the bottom mould thinner than the width of your press. Take your time when designing and pay loads of attention to clearances and tolerances of all parts that need to fit (this is definitely something we had to learn the hard way).
We placed a piece of MDF at the bottom to avoid warping of the mould under pressure but that was later changed to steel as we ended up having to create more space to comfortably fit the layup in.
We suspended the top mould using metal brackets from the local DIY shop and loads of nuts and bolts, which to be honest was our best spontaneous buy yet. The cat track was suspended using bungee cord so it is raised when the bladders are deflated (this creates your cavity to put the layup in the press). We also had to put a top sheet of MDF in so that the planks didn’t warp under pressure and, like the bottom sheet, was later replaced with steel.
After all your hard work it is likely it will all go smoothly but to be on the safe side, make sure you have a fire extinguisher!
We have some footage of our first press run so if you'd be interested to see that please leave me a comment and I'll get to editing it!
Happy building, Alice