Base and Shelf ConstructionThe base and shelf, as well as the other panels that make up the exterior of the cabinet can be constructed from the wood left over after cutting the two sides. The third full sheet of plywood can be kept aside for now. I ended up mounting the monitor in a way that doesn't require a shelf, but it's still an important structural component, and forms a nice division between the bottom and top halves of the cabinet.
I needed some additional tools for this step:
- Drill
- Drill Stand
- Drill Bits
- Countersink Bit
- Rubber Mallet
- Vernier Calipers
- Quick-Grip Bar Clamps
- Allen Keys
Again, it's a good idea to use a good quality drill. My first purchase was intended for home use and should have been adequate, but the chuck wobbled slightly as it rotated, making precision impossible. The same applies for drill bits - it's worth paying a bit more for a good set of bits that are guaranteed to be straight, will cut well, and stay sharp for longer.
The drill stand is like a small, portable drill press - perfect if you don't have a lot of room. Unlike a drill press, it can also be used to drill holes in larger panels away from the edge, which will become very useful. I found that some drill stands have quite a bit of play, so the position of the bit moves around and you lower it. Finding one with minimal play will make everything a lot easier.
Base PanelThe width of the base panel is the interior width of the cabinet (600mm) plus 5mm either side to fit into the slots. The length is the same length as the slots. Use the square to line up the cuts, the track saw to cut, then sand the edges so they're smooth. For the edges that will fit into the slots, it can also be helpful to sand along the length of the top and bottom corners so they're slightly rounded off. This will make it easier to fit into the slot.
Now's a good time to check that the panel fits. Starting at one end, fit one corner of the panel into the slot, then rotate to lower the rest of the panel while ensuring the end is firmly against the end of the slot. It probably won't go in easily because the plywood is usually slightly thicker than advertised and can sometimes be very slightly warped. You may need to wiggle it a bit, tap it with a rubber mallet, or even sand either the panel or slot.
Castor Mounting BoardsThe castor mounting boards are two pieces of plywood that run the length of the base on either side. They add extra strength to the base above the castor wheels, which will bear the weight of the cabinet. I chose a width of 100mm, and the length is the same length as the base. I used 6 countersunk stainless steel wood screws to secure each board to the base. They should be long enough that they screw a reasonable distance into the base (around 10mm is good), but not come out the other side.
Use the vernier calipers to measure the outer diameter of the wood screws (including the thread), select a matching bit, and, using the drill stand, drill the 6 holes in each mounting board. Choose the side of the board that will face the ground and use the countersink bit to cut the small indentation that will allow the screws to sit flush with the surface of the wood when fully tightened.
![](http://forum.arcadecontrols.com/index.php?PHPSESSID=1b72pl08jvuj7h058t8vfof8l6&action=dlattach;topic=164992.0;attach=393994)
Ensuring the base is properly seated in the slot, align the mounting board with the base, with one edge against the cabinet side. Clamp it in place, then push a screw through each hole and into the base to mark where it will screw in. These marks tell us where we need to drill the pilot holes in the base for the screws. Wood screws are self tapping, so you may be able to screw them straight in at this point, but plywood is dense and I've found that pilot holes are usually needed.
To drill the pilot holes, again use the calipers to measure the diameter of the screw excluding the thread, and select a matching bit. Use the drill stand to drill the holes, but adjust the depth stop so you don't drill all the way through. Select a depth approximately matching the length of screw exposed when it's fully screwed in to the mounting board.
Ledger BoardsThe base and shelf need to be attached to the sides of the cabinet. This is achieved with ledger boards that run the length of the panel and are securely connected to both components. I used 45mm x 19mm dressed pine. Wood screws are again used to attach the ledger board to the base (and shelf), but they will need to be longer and ideally a higher diameter for extra strength.
Similar to above, use the drill stand to drill screw-sized holes all the way through the long side of the ledger boards, at regular intervals, and alternately offset slightly from the center line. Staggering the screws this way adds strength by spreading the tension more evenly over the joined surfaces. This technique will be used throughout the cabinet. I couldn't find screws the right length to go all the way through the long side of the board with enough exposed thread, so I sunk the holes about 10mm deeper using a bit matching the diameter of the screw head. I think this looks better anyway (although it won't be visible from the outside, and is possibly slightly stronger too. Again, as above, clamp the ledger in position against the base and push screws into the holes to mark the pilot hole locations and drill the pilot holes.
Attaching the Ledgers to the SidesThis part is slightly more involved. You could again use wood screws for this and it would work fine, but I wanted to be able to easily assemble and disassemble the cabinet during construction. This means that I can test the fit of everything as I build it, but I can also pull everything apart if I need to make additions or changes. This is especially important because I don't know exactly how everything's going to work yet. I also want to be able to disassemble everything for painting and finishing before final assembly. For this reason, I opted for threaded inserts in the cabinet sides, and M6 countersunk socket screws (a type of bolt) through the ledgers. This will be very strong, easy to assemble and disassemble, and will also be invisible from outside the cabinet.
Start by marking the positions for staggered holes along the length of the ledgers, this time through the short side. Position and clamp the ledger board to the cabinet side. Drill pilot holes all the way through the ledger board and into the cabinet side. This helps to ensure that the threaded inserts will line up correctly with the holes. Because the holes in the side are far from the edges (and also because the side itself is hard to manoeuver), it is necessary to adjust the drill stand so the drill is swung off-center, allowing it to drill off the side of the base. This means that you can position the drill stand anywhere on the panel and drill straight down. I use a piece of scrap wood or cardboard under the base of the drill stand to prevent it from damaging the surface. I'm not sure if the drill stand is really designed to be used this way, but it works very well.
With the pilot holes drilled, unclamp the ledger board and countersink the holes on the upward facing side (the side that will face the interior of the cabinet). To finish the holes for the threaded inserts in the side, start by measuring the diameter of the threaded insert, excluding the external thread. They are usually slightly tapered, so measure a wider point near the top. Select a matching bit, and drill out the pilot holes. Take extra care at this stage, and while drilling the pilot holes to ensure the drill stand depth stop is set correctly so you don't drill all the way through the side.
![](http://forum.arcadecontrols.com/index.php?PHPSESSID=1b72pl08jvuj7h058t8vfof8l6&action=dlattach;topic=164992.0;attach=393978)
![](http://forum.arcadecontrols.com/index.php?PHPSESSID=1b72pl08jvuj7h058t8vfof8l6&action=dlattach;topic=164992.0;attach=393999)
With the holes drilled, carefully screw in the threaded inserts. These will usually have a hex (or allen key) drive. Work slowly, applying consistent downward pressure while ensuring the insert stays vertical. Once the outer thread has bitten sufficiently into the side, relax the downward pressure and screw it in the rest of the way, until the top is flat against the surface.
Test AssemblyAlthough the focus has been on building the base, the exact same methods are used for the shelf as well, with the only differences being that it doesn't require castor mounting boards, and the ledger boards sit below instead of above. With the base, shelf, and ledgers complete, it should now be possible to test everything together and stand the cabinet up.
![](http://forum.arcadecontrols.com/index.php?PHPSESSID=1b72pl08jvuj7h058t8vfof8l6&action=dlattach;topic=164992.0;attach=393997)