ZQDWMND Honeycomb Bed

The K40's head travels over roughly 300 by 200mm, or 12 by 8 inches. A bed that matches that area supports everything the beam can reach. A larger bed only helps if the cabinet has room for it, and many K40s have an exhaust duct lip at the back of the bay that eats into the depth.

Measure before you choose:

• the inside width and depth of the bay at the height the bed will sit
• the gap between the exhaust duct and the front wall
• the width of the opening you have to pass the bed through
• anything bolted to the bay floor, such as the old clamp's standoffs

Do not buy the largest size on the idea that more bed is better. On a stock K40 the extra area sits outside the beam's reach, and a bed that has to be forced through the opening will not come out easily for cleaning.

A margin of a few millimetres on each side makes it easier to lift the bed out for cleaning. Full cabinet figures are in the K40 dimensions guide.

The cell size matters most when you cut small parts. A piece has to span several cell walls to sit flat once it is free of the sheet. Anything narrower than a couple of cells can tip, catch the head or fall into the honeycomb.

The same openings that support the sheet also give the beam somewhere to go once it breaks through, and that is why you run a honeycomb instead of a solid plate.

Ways to work with a 5.5mm cell:

• Leave tabs on small parts so they stay in the sheet until the job ends.
• Cut small parts last, so a part that shifts cannot spoil the rest of the layout.
• Use a sacrificial card sheet under very small work to give it a continuous surface.
• Pin with the cells. Short pins or nails pushed into the cells make quick stops for repeat jigs.

Air assist helps here too. A jet at the nozzle pushes smoke down through the cut and into the open cells, where the exhaust can pull it away. Pair the bed with an air-assist head and pump, both covered on the K40 upgrades page, and the underside of your cuts stays cleaner.

1. Unplug the laser and take out the stock spring clamp and its plate.
2. Scrape and vacuum the bay floor. Old resin under a new bed makes it rock.
3. Measure the bed's height on arrival. ZQDWMND does not state it, and you need it to set focus.
4. Build a base. Standoffs, blocks or a lab jack under the corners bring the top surface to focus height.
5. Add corner stops. Small blocks screwed or glued to the base keep the bed from creeping and make it drop back in the same spot.
6. Push the head around by hand, laser off, to every corner of the travel and check nothing touches.

For focus, the bed height matters less than where the top of your material ends up. Most K40s run a 50.8mm focal-length lens, measured from the lens. Run a ramp test on scrap, find the thinnest line, and cut a spacer to that gap. Set focus and check the mirrors in one session, using the K40 alignment guide.

Recheck the spacer whenever you move from 3mm to 6mm stock. Focus follows the top surface of the material, so every change in thickness moves the target.

If you change stock thickness often, shims get tiresome. A motorised bed like the Lightobject Power Z table lets you set focus per job, and a honeycomb can sit on top of it.

Questions worth putting to the maker:

• What metal is the honeycomb: galvanized steel or aluminum? Steel holds magnets; aluminum does not.
• How tall is the bed, including the frame?
• Is the edge a folded frame or bare honeycomb?
• Is 5.5mm measured across the flats of each cell?
• Which of the five sizes ships under the version you picked?

Once it is in, care is the same as any honeycomb. Resin from plywood and acrylic builds up on the cell walls and bends the surface out of flat. Lift the bed every few sessions, brush it out, and scrape the worst deposits. Mask the back of show pieces, because the beam can mark the underside where it hits cell walls.

Check the bed flat before each big job. Lay a steel rule across it in two directions; a dip under a long cut line shows up as a cut that goes through at one end and not the other. A bent bed is cheaper to replace than a stack of ruined sheets.

If you want the build spelled out, the zwqpeic honeycomb and the LSYAMQF honeycomb both state galvanized iron with alloy edging, though their own size labels need confirming too. The ZQDWMND bed's advantage is the clear size range, with a 200 by 300mm option made for a K40-sized travel.