Slide-out HMI enclosure with drawer slides: how to build one

Short answer: build the slide-out as a drawer inside a sealed stainless shell, keep both drawer slides on the inside, and let the carrier's gasketed front face close the shell like a door. Size the slide pair at 4x the carrier weight, floored at 50 lb [23 kg] per pair. A 12 lb [5.4 kg] display carrier (weigh yours) then rides the 100 lb [45 kg] class with a static margin of 8.3. Keep 4 in [100 mm] of pull-out to clear the bezel and 12-18 in [300-460 mm] to reach the rear terminals. The moving joint never carries the water rating: the fixed shell keeps NEMA 4X and the display bezel keeps its own front rating. Ratings here are manufacturer ratings, not UL listed.

Drawer in a shell or exposed front

Two layouts work, and the room picks between them. A washdown line, an outdoor pad or a dusty process needs the drawer in a sealed shell: the station rides inside a 304 or 316L body, and the only joint that opens is the gasketed front flange. A dry indoor bench can run the exposed front, where the display bezel is the sealed face and the slides live outside the envelope.

NEMA 250 defines Type 4X as Type 4 hose-down plus corrosion resistance, and the sealed drawer delivers that while it is closed. The exposed layout rates only as high as the display front. An IP66 front survives the IEC 60529 jet test with a 12.5 mm nozzle at 100 L/min from 2.5 to 3 m for at least 3 min. An IP65 front takes the lighter 6.3 mm nozzle at 12.5 L/min. In US installations, NEC 110.28 keeps IP codes and enclosure type ratings separate, so a spec that says Type 4X wants that type in the marking, not only an IP code.

Either way the travel rule holds: 4 in [100 mm] is the floor, enough for the bezel to clear the shell opening and the latches to come within reach. Order 12-18 in [300-460 mm] when someone has to reach rear terminals and connectors on service days.

What you need

• Two full-extension ball-bearing slides, side-mount and detachable, pair rating at 4x the carrier weight and never below 50 lb [23 kg]. A 12 lb carrier lands on the 100 lb [45 kg] class; long 50 in [1,270 mm] rails come in the 125 lb [57 kg] class; heavy-duty tables reach 243 lb [110 kg] per pair. Detachable rails let the carrier lift off once the latches open.
• Shell and carrier sheet: 16 ga (0.060 in / 1.5 mm) stainless for walls, 0.08 in [2 mm] plate wherever slides and latches bolt, with rivet nuts for #8-#10 screws.
• Front-flange gasket cord, 1/4 in [6 mm] nominal: EPDM for hot-water washdown and caustic (about -50 to 150 C), silicone where heat leads (about -60 to 200 C).
• Two compression latches on a flange up to 16 in [400 mm] wide; add one for each extra 16 in.
• Glands for the fixed shell only: an M20 clamp range in typical gland tables is 5-13 mm [0.20-0.51 in] cable OD.
• A display carrier: a stainless HMI housing sized to the panel PC, with a VESA 100 (100 x 100 mm) rear pattern for M4 bolts and a gasketed rear cover.
• A straightedge for rail alignment and a paper strip for the gasket check.

Size the slides before you buy

Weigh everything that moves: housing, display, backplate, cable and latches. Assume 12 lb [5.4 kg] for a 10 in class carrier until you put it on a scale; a 15 in class display can double it. The 4x rule then sets the pair: 12 lb x 4 = 48 lb, which clears the 50 lb floor and lands on the 100 lb [45 kg] class.

Check the margin: 100 / 12 = 8.3. Slide ratings assume the load spread along the rails; a load hung at the front plate works the front bearings harder, and the 4x margin absorbs that. Each rail also shares half the weight, 6 lb [27 N] here.

The pull-out puts a moment on the shell too. Fully out, the carrier's center of gravity sits about 12 in [300 mm] ahead of the cabinet face, so the shell mounts see 12 lb x 12 in = 144 lb·in [16.3 N·m] of tip moment. Bolt the shell to structure, not to drywall, and pull with two hands. The class table below shows when a heavier carrier outgrows the 100 lb pair.

The datasheet number for the pair you buy wins over any class table here.

Lay out the two panels

Draw the shell front first: one opening that passes the display, cut 0.25 in [6 mm] oversize around the bezel so the moving plate never rubs. The carrier plate is larger than that opening and overlaps the shell wall from inside, with 6 mm of flat gasket land all round. Design the display position for a bezel that stands less than 6.4 mm proud of the mounting plate — one 10 in class terminal's dimension drawing puts the figure just under that — and set the closed stop so the flange seats before anything touches.

Cut the display cutout from the display maker's drawing and the shell holes from your layout; the guide to cutouts, glands and HMI windows covers the fundamentals skipped here. For the factory route, both panels come cut from one drawing: lay the holes out in the cutout designer and send the layout with the quote, in 304 or 316L.

Build the drawer

1. Bolt the slide sockets to an internal angle or backplate inside the shell, both rails on one plane. Lay a straightedge across them and shim until it sits flat, because a rail a millimetre high loads one side and binds the bearings.
2. Bolt the slides to the carrier backplate. A stainless HMI housing lands on its VESA 100 pattern with M4 screws; the rails pick up the plate edges with #8-#10 screws into rivet nuts.
3. Set the closed stop so the carrier flange seats and compresses the gasket before the bezel reaches the shell opening, holding the designed 6 mm bezel clearance.
4. Fit the flange gasket at 20-30 % squeeze. A 6 mm cord installs at about 3/16 in [5 mm] height, and the cord ends butt square at the corners with a dab of adhesive.
5. Clamp the display bezel into the carrier cutout on its own gasket, screws tight in a cross pattern; the bare-display bezel-and-gasket method covers this joint in detail.
6. Run the moving cables as a loop inside the shell: length = travel + 30 %, so a 12 in travel gets about a 16 in loop, and keep every bend at 6-10x the cable OD. An M12-style quick-disconnect at the joint is the tidy alternative.
7. Bring fixed wiring through glands in the shell wall only; the loop spans from that gland to the carrier.
8. Cycle the drawer 20 full strokes. It should glide with even resistance and latch without a slam; a hold-in detent or the latch itself keeps vibration from walking it open.
9. Lock out and verify absence of voltage before you wire the display supply.

Keep the rating where it belongs

The rating lives on the fixed shell, and it survives only if nothing crosses the wall. Slides bolt to the internal angle, so fasteners stay inside. Fixed wiring enters through glands sized to the cable, and entries cut after the shell arrives follow the field-drilled conduit-entry method that keeps a Type 4X rating. Skip the open vent: breather vents and the NEMA 4X rating have their own answer, and an open hole hands the rating back.

Every device sitting in a wall carries its own rating, and the weakest one sets the assembly. The carrier's display keeps its front seal: on our housings that is an IP65-type front seal with the display installed, manufacturer rated. The same logic that keeps a rating when an operator panel goes into a cabinet door applies here, because the front joint is a door joint, sealed closed, hinged on rails. And when the shell comes back from cutting with new holes, the rating it keeps is the one the mounted devices and gaskets still deliver.

Checks before you close it up

• Paper-strip pull: close the flange on a strip all round; it should pull out with even resistance. A slack end means the plate is not flat or a latch is not drawing.
• Imprint check: after 10 minutes closed, open and read the gasket. A continuous imprint at about 3/16 in [5 mm] width on the 1/4 in cord means 25 % squeeze landed.
• Travel check: full strokes measure the designed travel — 12 in [300 mm] in the worked example — with the stop holding the bezel clearance.
• Loop check: at full extension, no cable tension at the terminals, and the loop hangs free with bends above 6x OD.
• Hose check: 5 minutes from 10 ft [3 m] with a garden hose on the closed front finds gasket faults. It is a shop check, not the standard's test; the rating still rests on the manufacturer's rating of the shell.

Mistakes that cost the rating

• A slide screw through the outer wall: every wall penetration needs a gland or a sealed boss, so keep the slides on the internal angle.
• An open vent or louver on a drawer shell: seal it and handle condensation inside the sealed space instead.
• Gasket squeeze under 20 %: the flange leaks at the latch ends. Cord crushed flat takes a set within a season, so aim for 20-30 %.
• Bezel rubbing the shell opening: less than the designed 6 mm clearance shows up as scraped paint-thin edges and a sticky stroke.
• A tight cable loop: it drags the gland sideways and walks the carrier off its stop.
• Plated slides out in the wet on the exposed layout: fit 300-series stainless slides or move the station inside a shell.

What to order

The carrier is the catalog half: a housing from the stainless HMI housings takes the panel PC on its VESA 100 rear pattern, adds a gasketed rear cover, and carries an IP65-type front seal with the display installed, manufacturer rated. The 10.1 in HMI housing carried the worked example; the 15 in HMI housing is the step up when the display grows. If the cell runs hot, most panel electronics are 40 C (104 F) ambient class unless the datasheet says more, and high-temperature HMIs with IP66 sealing exist for hotter rooms.

The shell is the custom half: front wall with the display opening, internal slide angle and latch bosses, cut from 304 or 316L to your drawing and delivered in 10 business days, counted from your approval of the drawing. Check the layout against the custom stainless enclosure page, then send the drawing and the cutout layout with the quote request.

Catalog dimensions to compare

Compare these catalog dimensions with your component layout. Open each enclosure for its rating, material and usable space, then check those specifications against your application.

Questions