For some woodworkers, a CNC can add a lot to a shop. Modern technology has expanded what many woodworkers can do, from milling a large number of small parts with exact precision to creating beautiful (and replicable) relief carvings on drawer fronts, door panels, and trim. That and more can be done easily on a CNC with just a bit of know-how.

Of course, there are limitations with every tool, and when it comes to a CNC, cost and shop space are two big ones. An easy answer is to get a tabletop machine like the one above. While they may be more limited in what tasks they can take on, they’re certainly more moderate both financially and size-wise. Not only that, but you may be surprised at what can be accomplished on a CNC of this persuasion.

Our creative director, Chris Fitch, has been working with CNCs of all sizes for some time. Over that time, he identified three key issues with the smaller varieties — and incorporated three solutions. First, he wanted to create a base. This raises the CNC to a more comfortable working height, but it also gives room for a drawer to keep the wrenches, bits, and hold-downs corralled.

Second, he found that tables were limited by where the hold-downs could be placed, leaving “dead space” on an already small table. As an answer, he made the table extension you see above. Finally, he added a simple MDF spoilboard to protect the tabletop on through cuts.

MAKE IT YOUR OWN.

These designs were built around a Shark SD120 CNC. While these plans should work for similar machines, there will be small differences to account for. Additionally, you can take just what you need from this project. If you think a drawer and base would be nice, but you’re satisfied with your CNC’s table, then you can skip the table extension. After taking any differences for your machine into account, you can get to building.

Start with the BASE

This CNC upgrade begins at the very bottom. As you can see in Figure 1 above, I started off by putting together the frame of the base. While this portion of the project is simple, there’s no need to rush here — a well-made foundation is key to any build.

BASE BOTTOM.

The bottom piece of the base comes first, and there’s a bit of work to be done. I began by laying out the locations of the screws that would hold the sides and end to the base. Figures 1, 1a, and 1b provide the measurements you need to make the layout and drill the countersunk pilot holes.

You’ll notice a set of four through holes also need to be drilled into the bottom. These provide clearance to drive in the screws connecting the base top to your CNC. While we provide dimensions for these above, it’s best to measure your own CNC to be sure they’ll align properly. Once you have those through holes laid out, drill them with a 1" Forstner bit.

From here, a bit of rounding is all that’s needed. I used a quarter to mark the radius at each corner, then shaped them at the band saw, followed by sanding at the edge sander. Next, I installed a roundover bit in my router table and rounded off the top edge of the panel.

SIDES & END.

The bottom concludes most of the work on the base itself, but there are still a couple cuts left to make on the sides. They each have a rabbet along the inside, back edge to accept the end piece. After cutting the pieces to size, I used a dado blade to cut these rabbets.

PUTTING IT TOGETHER.

Since most of the joints here are butt joints, assembled with woodscrews and glue. I began by screwing the sides into the end (Figure 1a). This gives stability to position and clamp the three pieces to the base. Clamping squares work wonders here at keeping the sides and end in line. Once I was happy with my positioning, I flipped the assembly upside-down and used the holes already in the base to drill into the sides and end. To finish up, simply drive in the screws.

TOP & EXTENSION

As I mentioned earlier, we designed this project so you can take from it just what you need. While the extension table is a nice addition for smaller CNCs, it’s not necessary. The base you just made (along with the drawer on page 18) is a handy addition on its own. That said, the extension table is a great way to utilize otherwise “dead space,” and can provide more options for clamping down workpieces — something that can be a hassle depending on the exact design of your machine.

BASE TOP.

The top to the base is, in essence, a simpler version of the bottom. After sizing, lay out the position of the countersunk pilot holes to attach it to the rest of the base as in Figures 2 and 2a (along with the holes for the table if you’ll be building that). Before drilling these, head to the router table to roundover the upper edges.

I recommend not attaching the top quite yet, whether you’re building the extension table or not. Either way, the drawer slides you’ll be installing on the next page will be easier to add if you hold off on the base top.

EXTENSION TABLE.

If you’re not looking to build the extension table, feel free to scroll to the next page now. If it is something of interest, then the art below and the process below will help you out. The extension consists of a top, two sides, and a center. I began at the top, as it needs the most work, and I could resize the other pieces more easily if necessary.

Four stopped slots run down the width to provide clearance for hold-downs along the edge. Additionally, a groove and two rabbeted ends will join this piece to the other extension pieces. I started off with the slots, shown in Figures 2c and 2d.

After laying them out, I established each stopped end by drilling them out on the drill press. To create the slots, I used a straight bit to rout them out. I took several passes using a miter gauge and the fence at the router table, taking only a 1⁄4" off at a time. The rabbets came next. I used a dado blade buried in an auxiliary fence at the table saw to make these. Then I set the fence to cut the groove (Figure 2a).

SIDES & CENTER.

Now it was time to make the two sides. Since the groove is in the same position in these, I kept my fence the same and cut their grooves as well (Figure 2b). Then, I cut the table center to fit in between these pieces. With everything made, I glued these pieces up. Once dry, I seated the table extension to the top of the base using a few woodscrews (Figures 2 and 2a).

A Convenient Drawer

A simple drawer adds a lot to a project like this. It allows you to keep wrenches, bits, hold-downs, and other tools for your CNC close at hand and easy to find. This is a fairly by-the-book drawer, with full-extension slides to take advantage of its length and a no-nonsense plastic pull.

DRAWER JOINERY.

After cutting the pieces to size, the joinery is the next thing to look at on this drawer. There are three elements to the joinery here: dadoes in the side pieces, rabbets in the front and back, and a groove at the bottom of each.

First, came the dadoes. You can see these in Figures 3a and 3b above. Then I cut the rabbets in the front and back to create the matching tongues. I prefer this order of operations, as it allows me to size the tongues perfectly to the dadoes.

Finally, the grooves can be cut (Figure 3c). After installing the right size dado blade and setting the fence, I ran each piece through to make the grooves for the bottom plywood panel.

FINAL PIECES & ASSEMBLY.

Once you’ve cut the bottom to size and all the drawer parts are fitting nicely, glue up the drawer. After the clamps come off, mount the slides and install the drawer in the base. Now the top (with the extension table, if you made it) can be screwed in place.

With everything together, getting the perfect reveal on the false front is easy. Cut it to size, aiming for a 1⁄16" gap on each side. Before screwing it on, take a brief trip to the router table to round over the front edges. This roundover matches the top and bottom of the base, bringing these pieces together visually. From there, the false front can be attached (Figures 3b and 3c), followed by the plastic pull on its front.

That takes care of the base in its entirety. If you like what you’re left with so far, you could skip ahead to mounting the CNC on the next page. However, there’s one more upgrade on our list — one that’s both easy to make and more useful than you may think if you’re new to CNC work: a spoilboard.

SPOILBOARD

A spoilboard is used to support the workpiece being routed by the CNC machine, and to give the router something to cut into when it needs to go below the piece itself to separate parts. Unlike most of this project Baltic birch wouldn’t be a great choice of material here; MDF works far better. MDF is a good spoilboard material for two reasons.

First, you can’t beat the stability it offers. Given how precise CNC work is, even the small amount of natural movement a stable plywood can have will still cause problems. Second, MDF mills very well. There are often times when running your CNC that the bit will need to make a through cut into the spoilboard. The bonded fibers take these slight cuts from a router bit quite cleanly, leaving you with a smooth surface even after a number of these cuts have been made.

MAKING THE SPOILBOARD.

As you can see in Figure 4, there’s not much to the spoilboard. After cutting the piece of MDF to size, all it needs is a series of holes to lock it down to the CNC table. You can see the positioning I used for the holes in Figure 4a, but be sure that these will align with the tracks in your CNC before drilling.

After laying them out, I used a Forstner bit to drill the recesses for the heads, then a 1⁄4" drill bit to finish the clearance holes (Figure 4c). To attach the spoilboard, I used trusshead machine screws so there’d be plenty of surface area to hold the board down.

These thread through the table and into track nuts (Figure 4c). The recesses allow the bit to pass over the screws as need be. To attach the spoilboard, I ran the screws into their recesses and threaded the track nuts on to their ends. After feeding them into the track and positioning the board, I tightened them down with a screwdriver.

MOUNTING THE CNC.

Attaching your CNC machine to the table is easy. While it will differ slightly depending on the specifics of your CNC, I used woodscrews to attach mine. Four points work well, and most tables have a base of high-density polyethylene (HDPE). Similar to wood, HDPE bases are soft enough to drill pilot holes through, yet strong enough that the threads of your screws will hold securely in place.

Now, place your CNC on top of the base. I found it best to trace the legs in position. I then took the CNC off and drilled the pilot holes in both the base top and the CNC, measuring off the trace marks on the top. After lining the machine back up with my trace marks, I used the clearance holes drilled through the base bottom to screw the CNC in place (Figure 4b).

Whether you make one or all of these upgrades, any are a great addition. Of course, the best way to see what they add is to give your new setup a test run.