Trofast Frame Fitted with Antonius Runners for 8 Pull-Out Toy Bins

The plastic tilt-slots molded into a standard Trofast frame only accept genuine Trofast bins, and those bins tip forward when you pull them, so small parts slide to the front and jam the lip. Antonius runners are flat full-extension slides. Bolt a pair to each shelf level and the bin comes straight out, level, no tipping. Eight levels in a tall Trofast frame gives eight true drawers.

The number that kills most first attempts is internal width. Antonius runners in the 42cm and 57cm lengths are the ones people reach for, but their mounting geometry assumes the Ikea wardrobe cavity they were designed for. A Trofast frame’s inner clear width sits around 42cm depending on which generation you have. Measure yours before you buy anything. The older Trofast frames run slightly narrower than the current ones, and a 3mm difference decides whether the drawer glides or scrapes.

Measure the frame before you touch a runner

Pull a tape across the inside of the Trofast frame at three heights: top, middle, bottom. The middle almost always reads 1 to 2mm narrower because the side panels bow inward under the weight of a loaded frame. Write down the smallest of the three numbers. That is your working width, and every drawer box has to clear it with the runners attached.

Antonius runners eat 12.5mm per side when mounted, so 25mm total off your clear width. If your narrowest reading is 420mm, your drawer box outer width maxes at 395mm. Build to 393mm and you have a 1mm margin each side, which is what you want for something a four-year-old yanks open. Any tighter and humidity swelling in summer locks the drawer shut. Any looser and the box rattles and racks.

The side panels of a Trofast frame are particleboard with a melamine skin, roughly 15mm thick. That skin is slick and the core is soft. Runner screws driven straight into it will strip within a few months of daily pulling. This is where the birch ply reinforcement earns its place. Cut two strips of 12mm birch ply the full inner height of the frame, 60mm wide, and glue plus screw them to the inside faces where the runners will land. Now every runner screw bites into solid ply, not crumbly melamine core.

The drawer boxes

Eight boxes is a lot of repetitive cutting. Batch it. For toy storage a drawer 100mm to 120mm deep handles most things, and the shallower you go the more levels you fit. I run four shallow boxes at the top for small parts and four deeper ones below for bulkier stuff.

12mm birch ply for the sides and back, 6mm ply for the bottom set into a groove. A simple rabbet joint at the corners, glued and pinned, is plenty strong for toy loads. Skip the dovetails. Nobody is inspecting the joinery on a kid’s toy drawer and the pin nailer saves you two hours across eight boxes. Rubio Monocoat in a neutral tone on the birch faces reads clean against the white Trofast melamine, and one coat is genuinely one coat, no topcoat, so eight box exteriors go quick.

Runner spacing is the real work

Here is the part that bites people. Antonius runners have to sit at exactly the same height on both side panels or the drawer binds diagonally. Off by 2mm and the slide stiffens; off by 4mm and it jams solid halfway out.

Make a story stick. Take a scrap of the birch ply the full inner height and mark every runner centreline on it, top to bottom, for all eight levels. Drill nothing off a tape measure repeated sixteen times, because cumulative tape error across eight levels stacks up to real misalignment by the top. The story stick transfers the same marks to both panels identically. Clamp it against one panel, punch your screw centres, flip it against the other, punch again. Both sides now match to within the thickness of your pencil line.

Spacing between levels: allow the drawer box height plus the runner clearance plus 10mm of finger room to lift toys out without scraping knuckles on the box above. For a 100mm box that is roughly 125mm centre to centre. Eight of those needs about 1000mm of clear internal height, which a full-height Trofast frame gives you with a little to spare.

Mount the cabinet member of each runner to the ply-reinforced panel first, all sixteen, using the story stick marks. Then mount the drawer member to each box. The two halves clip together on install. Full-extension Antonius runners let the whole drawer clear the frame, so a kid can see every crayon at the back, which is the entire point of ditching the tilt bins.

Load rating and the sag question

Antonius runners are rated well above what a toy drawer will ever see, so runner failure is not your worry. Frame racking is. A Trofast frame is designed to be loaded low, with heavy Trofast bins near the floor. Convert it to eight full-extension drawers and every drawer can be pulled out at once, cantilevering weight forward. A tall frame with all eight open and loaded will tip.

Anchor the frame to the wall. Ikea supplies a strap anchor with the frame; use it, and add a second one at the top if your frame is the tall version. The birch ply strips you glued inside also stiffen the whole carcass against racking, which is a side benefit of doing the reinforcement for the screws.

A worked example: fitting 42cm runners to a 420mm frame

Say your smallest inner reading is 420mm and you bought 42cm Antonius runners. Runner mount depth from the panel face is 12.5mm each side, total 25mm. Drawer box outer width target: 420 minus 25 minus 2mm total clearance equals 393mm. Sides are 12mm ply, so inner box width is 393 minus 24 equals 369mm. Groove for the 6mm bottom sits 8mm up from the box base, cut 6mm wide and 4mm deep into the sides and back.

Box depth follows the runner length. A 42cm runner wants a drawer box at least 400mm front to back to bolt the drawer member across its full span. If your Trofast frame is only 380mm deep internally, the 42cm runner will not fit the depth and you need the shorter runner or a shallower frame. Check depth and width both. People obsess over width and get caught by depth.

Height per level from the earlier spacing: 125mm centre to centre times eight is 1000mm of runner-mount range. Mark those eight centrelines on the story stick starting 60mm up from the frame floor, so the bottom drawer clears the base rail.

Fronts, if you want them

Bare birch drawer boxes look fine. Superfront makes fronts, handles, and legs sized to Ikea carcasses, and their fronts will screw onto an Antonius drawer box through the box front panel. A kid does not need a handle they can trap fingers in; a simple finger pull routed into the top edge of each box front works and there is nothing to break off.

The open question is durability under a specific kind of abuse: a child standing on a fully extended bottom drawer to reach the top one. No runner rating covers a 20kg toddler using the drawer as a step, and that failure mode, not the toy load, is what eventually bends a slide. Whether to build in a hard stop that prevents full extension on the lower drawers, or just accept the eventual replacement, is the decision the spec sheet cannot make for you.