A Rolling Side Table from 2040 Aluminum Extrusion and 18mm Pre-Finished Baltic Birch Plywood

I have been curious about aluminum t-slot extrusion for a while. You have probably seen the stuff. It goes by a lot of names depending on where you buy it and what you are building: t-slot, t-rail, structural framing, profile aluminum, "the 8020 stuff," 2020, 2040, 4040. It is the backbone of a million 3D printers, CNC machines, workbench frames, photo stands, and DIY shop carts. The slot down each face accepts a captive nut, which lets you bolt brackets, fasteners, rollers, and accessories anywhere along the length without drilling. It is a Lego set for grown-ups with a torque wrench.

I needed a small rolling side table next to the recliner in my workspace. Not big. Not fancy. Something that holds a coffee, a book, a battery charger, and a few small tools, and that I can roll out of the way when I want to vacuum. I figured it was the perfect excuse to finally build something with extrusion and use it as a chance to put a custom-cut piece of MakerStock 18mm pre-finished Baltic Birch on top.

The result is the cart you see above. Total parts list at the bottom of the post. No fancy joinery, no glue-up, no finishing schedule, no clamping. The whole thing comes apart with an Allen key. If I want to make it taller, shorter, wider, or add a third drawer, I undo six bolts.

Here is how I got there, and what I learned about the materials along the way.

Why 2040 (and not 2020 or 4040)

Aluminum extrusion comes in a confusing pile of sizes. The metric standard sizes you will run into most often are:

• 2020: 20mm by 20mm. Thin and light. Great for camera rigs, tiny enclosures, and the inside of small machines. For a piece of furniture you can lean on, it looks spindly.
• 4040: 40mm by 40mm. Chunky and rigid. Looks great on a CNC gantry. On a side table it looks like overkill, like you parked a forklift next to your couch.
• 2040: 20mm by 40mm. The Goldilocks size. Substantial enough that it reads as "real furniture" when you see it from the side, slim enough that it does not dominate the room.

I bought all three at one point or another for various projects. 2040 is the one I keep coming back to for furniture-scale builds. The wider face gives you more room to fasten brackets, the narrower edge keeps the silhouette clean, and you get two slots on the long faces, one on each short face.

The slot on this stuff accepts M5 and M6 fasteners depending on the source. Both work fine. M5 is more common in the small accessory hardware. M6 has more meat for structural connections. I used both on this build.

One small thing that surprised me the first time I worked with extrusion: you do not have to slide the t-nuts in from the end of the rail. There are drop-in t-nuts that go in from the face. You insert them flat into the slot, then rotate them ninety degrees so they catch. That means you can add a fastener to a fully assembled frame without disassembling anything. Once you discover this, you stop dreading the moment you forgot to load enough nuts before bolting things together.

Cutting the rail

If you order extrusion at length, the supplier will cut it for you. If you order longer pieces and want to size them yourself, do not be intimidated. My first instinct was a hacksaw, and you know how that goes: the cut starts square and ends in a parallelogram. Skip the hacksaw if you have a powered option.

I figured I would at least try the table saw. The blade in the saw at the time was a well-worn 50-tooth Freud 10-inch wood blade, nothing special, certainly not a blade made for aluminum. There are dedicated non-ferrous blades that have a slightly different tooth geometry and they are excellent, but they are also expensive, and I did not have one on hand. So I went ahead with the wood blade and braced for some screeching.

It cut like a hot knife through butter. Not even loud. Just a tidy, square cut, the way the saw cuts a piece of poplar. The aluminum chips that come off look like silver glitter and pile up in front of the blade.

A few real notes if you want to do this:

• Use the crosscut sled, miter gauge, or sliding table on your saw. Do not freehand it against the fence.
• Wear safety glasses. The chips are sharp and they fly.
• Support both ends of the rail so the cut-off does not pinch the blade or fall onto your hand.
• A chop saw or miter saw would probably be cleaner still. A bandsaw works too. A relatively fine-toothed blade is best, but in my experience almost any reasonable blade handles 2040 fine.

If you are doing a lot of cuts, get a dedicated non-ferrous blade. For a one-off cart with eight cuts, your existing wood blade is almost certainly going to be fine.

The frame

The structural frame is just a rectangle of 2040 with vertical legs at the corners and a horizontal cross-rail front and back at each drawer level. There is nothing clever about the geometry. Pick the height you want, the footprint you want, and the number of drawer slots you want.

The corners are joined with internal angle brackets, which is the standard hardware for this kind of rail. They sit inside the slot, two M5 cap screws per leg, and they are stiff enough that the cart racks less than my actual workbench. Tighten everything snug, not gorilla-tight: the slot will deform if you crank too hard.

If you would rather not use brackets, there is another standard technique: drill a clearance hole through one rail, tap M6 threads directly into the open end of the receiving rail, and bolt them together end-to-face. There are inexpensive jigs for this on Amazon and the usual suspects. I went with brackets because I want to take this apart someday and using brackets means no permanent threads in the rail.

The top

For the top I wanted a specific size, 15-3/4 inches by 20 inches, because that is what fit my space and the geometry of the cart. I did not want a stock-size top that I would have to trim. I ordered a custom-cut piece of MakerStock 18mm pre-finished Baltic Birch plywood at exactly that size.

A few things to say about that material because it is the whole reason I am writing this on the MakerStock blog and not on a sticky note.

Baltic Birch is a high-end plywood originally produced in the Baltic states. It is laminated from thin birch veneers, all the way through, with no voids and no soft inner core. When you cut it, the edge shows a pinstripe pattern from the layers, and that edge is a feature, not a defect. People build furniture and design objects specifically to show off the laminations. The top on this build is a small case in point: every edge looks like a tiny little drawing of itself.

The "pre-finished" part is what makes this build a one-evening project instead of a one-weekend project. The top arrived with a UV-cured coating already applied to both faces. UV cured means the finish is hardened in seconds under ultraviolet light during manufacturing, which gets you a denser, more abrasion-resistant film than you can practically build up with hand-applied finish at home. No sanding, no staining, no varnish, no waiting. The face of the panel is ready to live on as soon as it arrives.

The "custom-cut" part is the other half. MakerStock will cut Baltic Birch panels to the exact dimensions you specify, in less-than-full-sheet quantities. A standard Baltic Birch sheet is 5 feet by 5 feet, which is a great size if you need a lot of plywood and a terrible size if you need a single 15-3/4 by 20 inch top and you live in a one-car garage. Custom size, less-than-full-sheet, delivered to your door in the dimensions you actually need. That is the whole pitch and it is a real one for project work like this.

Routing the radius corners

I wanted a 10mm radius on the corners of the top. Crisp 90-degree corners read as cheap on a piece this small, and a tight radius is the easiest way to make a flat panel feel intentional.

I 3D-printed a router template with a 10mm radius cutout. STL files for this exact purpose are all over MakerWorld and Printables. You can also buy aluminum versions on Amazon if you do not have a printer.

To use a template like this you need a straight-flute router bit with a bearing on top, sometimes called a flush trim bit or a pattern bit. The bearing rides the template, the cutter trims the wood to match. Three things matter:

1. Practice on scrap. Always. The first time you do this you will catch a corner and put a small chip in your panel. Better that the chip is in scrap.
2. Direction matters. You want the work on your left and the bit moving away from you (climb cut and conventional cut behave very differently on radius work). If you go the wrong way the router tries to claw itself across the workpiece, which is exciting in the bad way.
3. Speed. Too fast and you burn the wood. Too slow and you also burn the wood. Medium speed, steady feed, no pausing.

After routing, sand the edges with a random orbit sander. I went 100 grit to clean up saw marks and any minor router burns, then 240 grit to smooth it. The face of the panel is already finished, so do not sand the face: stay on the edge.

Edge finish (or no finish)

Because the panel is pre-finished on the faces, you have a choice on the edges. Option one: leave them raw. The Baltic Birch laminations look great as bare wood, and on a piece that lives indoors and dry, raw edges are fine for years. Option two: hit the edges with a wipe-on polyurethane to seal them. I like Minwax wipe-on poly in satin for this. One thin coat with a rag, let it dry, optional second coat. It darkens the edge slightly and seals it against humidity and the inevitable spilled coffee.

Mounting the top to the frame

I did not want any visible fasteners through the top. That ruled out the obvious approach of countersinking screws from above. I also did not want to glue or screw it permanently, because the whole point of an extrusion build is that you can take it apart.

The solution is a small cast aluminum corner bracket that mounts to the upper rail with an M5 screw and clamps the top from underneath. You can see them in the photos: triangular foot on the rail, a single M5 going up into the bottom face of the plywood. I used six of them around the perimeter. The mounting holes in the bracket needed a small enlargement to clear M5; that is a thirty-second job with a step bit.

Because everything is bolted, I can pull the top off in five minutes if I want to refinish it, swap it out for a different color, or replace it with a piece of stone or laminate later. That kind of optionality is one of the underrated wins of building this way.

Drawers from Sidio crates

This is the trick I am most pleased with on the build. Instead of designing and building wooden drawers, I used Sidio crates as the storage units. Sidio crates are stackable plastic bins that come in several heights and a handful of decent colors (I used a green and a blue). They look good on their own. They are tough. And, critically, they have an 11mm groove molded around the top edge of each crate that runs the full length of both long sides.

That groove is a drawer slide waiting to happen.

My first try was the simplest possible solution: drop a row of three or four M5 socket head cap screws into the inner rail with the heads sticking out into the slot the crate would occupy. The screw heads engage the 11mm groove and the crate slides on them. This works. It is also fussy: the spacing has to be right, and when you pull the crate out fast it tends to rock side to side.

First attempt at the drawer slide: just a row of M5 socket head cap screws in the rail engaging the molded groove on the crate. It worked, but it was fussy.

The better solution was to design and 3D-print a slide rail that fits the side groove of the Sidio crate exactly. About 250mm long (10 inches), full contact along the groove, three M5 button heads from below into t-nuts in the rail. The crate slides like a real drawer. No rock, no bind, easy to pull out and easy to push back in. STEP file is at the bottom of the post.

The crate height determines the drawer height. Sidio sells crates in several heights. You can mix and match: a shallow crate up top for pens and tools, a deeper one below for books and chargers. Because the cross-rails are bolted, you can move them up or down whenever you want to change the drawer geometry.

Casters

I wanted the cart to roll. Casters with M8 studs are easy to find, including with brakes. The challenge is that the bottom of a 2040 extrusion has a center hole, but it is not threaded for an M8 stud directly.

The trick: a 12mm diameter stainless threaded sleeve with M8 internal threads. The sleeve drops into the center hole of the rail, the caster stud threads into the sleeve, done. The sleeve has some clearance in the hole, so to lock it in place I drilled a small clearance hole in the side face of the rail near the bottom and ran an M5 socket head cap screw through the side, into a t-nut in the slot, that pinches the sleeve from the side. No tapping required. The structural aluminum stays uncut except for the small clearance hole, which is invisible once the caster is on.

What I would do differently

Two small things, neither of them deal-breakers:

I would print the drawer slides in a tougher filament than PLA from the start. PLA is fine for indoor furniture in a climate-controlled house. PETG or ASA would be more forgiving in a hot garage or workshop, where PLA can creep over time under sustained load.

Beyond that, I am happy with it. The cart cost less than a comparable steel rolling shop cart, the top will outlast the rest of my furniture thanks to the UV-cured coating, and I can rebuild the whole thing into a different cart in a Saturday morning if my needs change.

Parts list

Frame

• 2040 aluminum extrusion, mill-finish or anodized, total length per your dimensions. For my 15-3/4 x 20 inch footprint with two crate drawers, I used roughly 6 meters of 2040.
• M5 socket head cap screws (a generous handful)
• M5 drop-in t-nuts (more than you think you need; buy spares)
• M6 fasteners and t-nuts if your bracket choice requires them
• Internal corner gusset brackets (eight, one per corner inside and out)
• Cast aluminum L-brackets for top mounting (six)

Top

• One custom-cut piece of MakerStock 18mm pre-finished Baltic Birch plywood, 15-3/4" x 20" or your preferred dimensions
• 10mm radius router template (3D-printed or aluminum)
• Bearing-guided straight flute router bit (sometimes called a flush trim or pattern bit)
• Random orbit sander, 100 grit and 240 grit discs
• Optional: Minwax satin wipe-on polyurethane for the edges

Drawers

• Sidio crates in your chosen heights and colors, two for the build shown
• 3D-printed drawer slides (STEP file linked below) in PLA, PETG, or ASA
• M5 button head cap screws and t-nuts to mount the slides

Casters

• Four M8-stud swivel casters, with brakes if you want them
• Four 12mm diameter stainless threaded sleeves, M8 internal thread
• Four M5 socket head cap screws for sleeve retention
• Four M5 t-nuts

Files

• Drawer slide STEP file.
• Router template STL files: search "10mm corner radius router template" on MakerWorld or Printables

Want a custom-cut piece of pre-finished Baltic Birch?

The whole reason this project went from "I should build something" to "I built it on a Sunday" is that the top arrived ready to install. No finishing, no waiting, and exactly the size I needed.

If you want to do something similar, MakerStock cuts Baltic Birch panels to the dimensions you specify, in less-than-full-sheet quantities, with the UV-cured pre-finish already applied. 18mm is the right thickness for furniture tops, shelving, and small case work. Tell us what size you need and what you are building, and we will get you what you need without forcing you to buy a full 5x5 sheet you do not have room to store anyway.

If you build something with it, send pictures. We like seeing what people make.