TEN-HIGH 40W CO2 Laser Tube

That lines up with the long-standing K40 rule of thumb: stay at or under roughly 15mA on a 40W tube, and lower when you can. Running hotter than that may cut a little faster today, but it is widely blamed for shortened tube life.

• Find the percentage that gives 12mA on your meter and mark it on the panel.
• Use 15mA only for the last pass on a stubborn cut.
• If jobs need more than 15mA to cut, clean and align the optics before turning up the current.

The tube is 40W rated; the upgraded version is listed as suitable for 40–45W machines. Either way, treat the rated power as a ceiling. The K40 tube and supply guide covers current, pinouts and safe settings in more depth.

1. Fill the reservoir first. Use distilled water or a purpose-made non-conductive coolant, never tap water.
2. Connect the inlet to the nipple at the high-voltage end, on the lower side.
3. Connect the outlet at the low-voltage end, running back to the reservoir.
4. Run the pump and watch. Roll the tube gently in its mounts until trapped bubbles clear from the outlet end.
5. Check for leaks at both nipples before connecting any power.

Warm water costs power and life. A bucket and aquarium pump works for short jobs, but water temperature climbs during long cutting sessions. Many owners aim to keep it below about 20–25°C; a CW-3000-style chiller or a larger reservoir helps in a warm shop.

• Fit a water-flow switch if your K40 lacks one, so the tube cannot fire dry.
• Change the water when it turns cloudy or grows algae.
• Never let the tube freeze; ice in the jacket cracks the glass.

Why the high-voltage end first? The usual explanation is that it runs hotter, so it should meet the coldest water. Filling from the bottom and exiting from the top also pushes air out of the jacket instead of trapping it in a pocket above the bore.

The packing is sponge, double foam and a double box. Glass tubes still break in transit, so open the box on arrival, look along the full length for cracks, and check both ends and the internal spiral. Photograph any damage before you do anything else.

1. Unplug and wait. The K40 supply produces tens of thousands of volts; leave it unplugged for several minutes before touching the old tube's leads.
2. Remove the old tube. Drain the water, disconnect the leads, and lift it out by the glass body, not the nipples.
3. Check the fit. The tube is 700mm long (±10mm) and 50mm wide, the stock K40 size; see the K40 dimensions page for the bay.
4. Mount it level in the cradles with the output end towards mirror one, padding the clamps so they grip without squeezing.
5. Connect the leads. The pre-wired high-voltage lead goes to the supply's HV output; insulate the joint well.
6. Water on, then power. Confirm flow and no bubbles before the first test fire.

A new tube almost never lines up exactly where the old one fired. Expect to adjust the tube height and mirror one, then walk the beam through the rest with the alignment method.

Run the first cuts at 10mA and watch the meter settle. A new tube that jumps around or will not strike steadily should go back inside the warranty window.

• Classic tube: 40W, pre-wired high- and low-voltage leads, nano gold catalyst coating.
• Upgraded tube: listed for 40–45W, with a soldered high-voltage end under heat-shrink and a high-voltage protective sleeve, a new terminal on the negative end, and a metal head on the negative side. Remove the dust cover on the left before use.

The sleeved high-voltage end on the upgraded tube targets the usual problems at that joint: arcing, leakage and a lead that pulls loose. On a first tube swap, that pre-finished joint removes the fiddliest step. TEN-HIGH credits its coating with more power and a longer life; treat those as maker claims rather than guarantees.

How long either will last depends on you. Glass CO2 tubes in this class are commonly quoted anywhere from about a thousand to a few thousand hours. Current, cooling and storage decide where yours lands.

Set the TEN-HIGH against the other tubes:

• The Cloudray CR35 is 720mm long, so check your bay has the extra length.
• The XYNLHZQ tube matches the 700mm x 50mm size, with glass-head or metal-head ends.
• TEN-HIGH's published current spec is the reason to pick it when you want numbers to run by.

Store a spare tube flat, padded and away from frost if you keep one on the shelf. Better still, order the replacement when the current tube starts to fade, since long storage is exactly what TEN-HIGH warns against.