Jay Bates shared the woodworking project featured in this video.
Jay walks through the process of designing and building a vertical table addition for his CNC router, explaining why this accessory opens up a whole new world of joinery possibilities. From hidden drawers in live edge coffee tables to box joints and dovetails cut directly into the end grain of a board, a vertical table lets a CNC do things a flat spoilboard simply can’t.
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Why a Vertical Table Matters
Jay’s CNC router runs on an open gantry system that can be configured almost infinitely, which means a vertical table can be built to whatever size fits the machine. He points to a favorite past project, a live edge coffee table with a hidden drawer, as the perfect example of what becomes possible. The legs on that piece were joined to the slab using mortise and tenon joinery cut entirely on a vertical table, with no mechanical fasteners anywhere in the build.
Beyond mortise and tenon work, Jay notes that a vertical table also opens the door to dovetails, dowel joinery, and even decorative waterfall-style joints with inlay. Essentially, any joint that requires cutting into the end or edge grain of a board becomes achievable once material can be clamped vertically against the spindle.
Planning the Table’s Design
Before cutting anything, Jay worked through several design decisions. He wanted enough width to handle large panels while leaving room on each side to clamp material close to the edge. He also decided against building in a system for cutting angled tenons, since he rarely used that feature on his previous machine. Instead, he plans to handle angles with a simple wedge clamped to the flat table surface when needed.
Clamping was a major consideration. Rather than relying on T-track style hold-downs, which don’t work well with thicker vertical stock, Jay chose a layout of threaded inserts and dog holes that allow standard F-clamps to secure material anywhere across the table. This keeps the design simple while still giving plenty of flexibility for different board sizes.
Building in Adjustability
Because a CNC’s accuracy depends on everything being perfectly square, Jay built a significant amount of fine adjustment into the vertical table. Using T-nuts and set screws at multiple points, he can tweak the top and bottom of each upright independently, bring the left and right sides into parallel with the machine’s axis, and ensure the entire face is perpendicular to the horizontal spoilboard.
He also built in a system of repeatable reference points, similar to the dog holes he uses on his horizontal table, so that any new workpiece can be indexed to the same starting location every time. This kind of repeatability is what makes a vertical table genuinely useful for production, not just for one-off joinery experiments.
Cutting the Joinery
With the layout settled, Jay moved into cutting the actual tenons and box joints on test stock. The process breaks down into a few distinct toolpaths: a scoring pass to prevent tearout, a roughing pass to remove bulk material, and a finishing pass to bring the tenon to its final size. He notes that his toolpaths weren’t fully optimized for speed, since this was a one-off test rather than a production run, but the results were clean and accurate.
He also compares cutting with and without a scoring pass, finding only a minor difference in surface quality. For anyone chasing flawless results, the scoring pass is worth the extra time, but it isn’t strictly necessary for most projects.
A Lesson in Material Quality
A big portion of the video turns into an unexpected lesson about MDF quality. Jay used a cheaper, more convenient sheet than his usual supplier and quickly realized the material behaved differently under the router. It felt more porous, left more fuzz at cut edges, and varied noticeably in thickness across the sheet.
That thickness variation ended up causing real problems once the table was assembled, introducing a slight lean in the upright that was difficult to track down. Jay eventually traced it back to a bow in the original sheet goods rather than an error in his own setup or calibration. It’s a useful reminder that not all sheet material is created equal, and that saving a little money or driving time isn’t always worth it when precision matters.
Troubleshooting and Calibration
Dialing in the vertical table square to the machine’s axes took patience. Jay used a dial indicator style digital readout, a reliable square, and eventually a long straightedge to track down exactly where the table was out of alignment. What first looked like a bulge in the panel turned out to be a bow introduced by the low-quality MDF itself.
Rather than chasing perfection endlessly, Jay makes the practical call that some of these deviations are small enough not to affect real-world results once glue is introduced into a joint. He outlines a few options moving forward, including surfacing the panel to flatten it, or rebuilding the table entirely with higher grade material and a slightly revised clamping layout.
Final Thoughts on the Build
Despite the headaches caused by inconsistent sheet goods, Jay considers the vertical table a success. It allows clamping of panels up to a very wide span by staggering the mounting holes in different rows, which means even oversized glue-ups or waterfall style tabletops become possible down the road.
Jay closes by admitting that if he rebuilt the table today, he would reach for higher grade material from the start, since the entire ordeal reinforced how much small inconsistencies in MDF can snowball into bigger alignment issues on a precision fixture like this.
This project is a good reminder that a CNC’s capabilities are only as good as the fixtures built around it. A well designed vertical table can unlock joinery that would otherwise require a dedicated router table or a lot of manual layout work, and Jay’s process offers a practical blueprint for anyone looking to add the same capability to their own machine.
See Jay’s plans here: https://jayscustomcreations.com/product-category/plans/?wpam_id=62
Matt’s Take
These are my personal thoughts and tips based on my own experience in the shop. This section is not written, reviewed, or endorsed by the original creator of this project.
This is a great example of how much fixture design matters when you’re working with a CNC. The machine itself can be dead accurate, but if the table, jig, or spoilboard it’s referencing isn’t true, none of that accuracy makes it to the final cut. Building adjustability into a fixture like this, rather than assuming everything will line up perfectly on the first try, is just smart practice for any precision work, CNC or otherwise.
The MDF issue is worth paying attention to. Not all sheet goods are milled to the same tolerance, and thickness variation across a panel can be sneaky since it often isn’t visible until you’re relying on that surface as a reference plane. For fixtures, jigs, or anything where flatness and squareness matter, it’s usually worth spending a bit more on a known, consistent product rather than grabbing whatever sheet is closest at hand. Baltic birch plywood is another option worth considering for fixtures like this, since it tends to hold flatness and dimension more reliably than cheaper MDF.
On the clamping side, using threaded inserts and dog holes with standard F-clamps is a solid approach for vertical work. T-track can bind or flex under thicker stock, so having a grid of solid anchor points gives you more flexibility to clamp close to the cut without fighting the hardware.
If you’re following along at home, take your time with the squaring process. A dial indicator and a good straightedge are worth having in the shop, and double-checking for bow in your material before you start chasing alignment issues can save a lot of frustration.