zwqpeic K40 Honeycomb Bed

Then measure your own machine. The K40 moves the head over roughly 300 by 200mm, about 12 by 8 inches, and the cabinet around that area differs from one build to the next. Many K40s have an exhaust duct that pokes into the back of the bay, and the stock clamp bed sits on standoffs that set the floor height.

Take these measurements with a steel rule, lid open and machine unplugged:

• inside width and depth of the bay at bed height
• distance from the exhaust duct lip to the front wall
• depth from the lens to the bay floor
• any wiring, screws or brackets on the bay floor

A bed larger than the travel is not wasted. It gives a full sheet somewhere flat to rest, and the edges outside the beam's reach make handy stops for jigs. It is only a problem if it will not go through the door. Full cabinet and work-area figures are in the K40 dimensions guide.

1. Unplug the machine and wait before reaching into the bay. The tube's power supply is at the other end of the cabinet, but treat every K40 cabinet as live until the cord is out.
2. Remove the clamp assembly. It is usually held by a few screws on standoffs. Keep the screws in a cup; you may want them for spacers later.
3. Clean the bay floor. Years of resin and ash collect under the stock bed. Scrape and vacuum before the new bed goes in.
4. Set the honeycomb on a level base. Use blocks, nuts on threaded rod or a lab jack so all four corners sit at the same height.
5. Check flatness. Lay a straightedge across the cells in both directions and look for light underneath.

zwqpeic uses galvanized iron for the honeycomb and an alloy strip around the edge, and it describes the bed as hard to deform. Treat it gently anyway. Honeycomb cells crush if you lean on them or drop a heavy offcut, and a dent under the work puts that spot out of focus.

With the clamp gone and the bed level, the only job left is focus.

Most K40s use a lens with a 50.8mm focal length. Focus is measured from the lens itself, not from the bottom of the head, so a head with an air cone changes the gap you see. Find the real focus with a ramp test instead of trusting a number:

1. Prop a strip of scrap wood at an angle, one end on the bed and the other raised a few millimetres.
2. Fire a straight low-power line along the strip.
3. Find the thinnest point of the line and measure from there to the underside of the head.
4. Cut a spacer block to that height and use it for every job.

To hit that height with a 22mm bed, you have three choices:

• Shims or standoffs under the bed, cut to one height for your most common stock
• A lab jack, which lets you move the bed per job but is fiddly to keep level
• A motorised table like the Lightobject Power Z table, which handles thick and thin stock without shims

Recheck focus whenever you change material thickness. A 3mm sheet and a 6mm sheet need the bed in two different places, and cutting out of focus wastes power the K40 does not have to spare. The alignment guide covers focus alongside the mirror checks, and the K40 setup guide covers the first test cuts.

It has limits, and knowing them saves material:

• Back-side marks. The beam still hits the cell walls under a cut line and can leave faint scorch marks on the underside. Mask the back of show pieces.
• Resin build-up. Cutting plywood and acrylic leaves residue in the cells. Scrape and brush the bed every few sessions so the surface stays flat.
• Tiny parts. Small cut pieces can tip into the cells or shift. Leave small tabs or cut them last.
• Fire. Debris collects under a honeycomb. Empty the bay floor often; a pile of scraps under the bed is fuel.

Galvanized iron is magnetic, so small magnets hold warped sheets flat without tape. Keep them out of the head's path.

A honeycomb works best with air assist. The jet pushes smoke down through the cut, the open cells give it somewhere to go, and the exhaust fan carries it out instead of letting it hang under the lens.

The LSYAMQF honeycomb is described in identical terms, so pick on whichever maker confirms the size you need. The ZQDWMND bed names a 5.5mm cell and five sizes, including 220 by 320mm and 200 by 300mm. For the full upgrade order, bed included, see K40 upgrades.