DIY 3D Tech

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eBay K40 CO2 Laser – Step by Step Guide To Replace a CO2 Laser Tube!

In this episode, we will be showing Step by Step how to replace your eBay / k40 40 watt CO2 laser tube! Please be sure to watch the complete video as well as read all of the notes below BEFORE starting!

The first step is to source a replacement tube and we did a lot of home work to find the best price to quality as many vendors wanted almost the price of a complete new machine just for the tube, or some of the cheaper ones were known to ship poor quality or even broken tubes. Here for just over $100 USD with free shipping (at the time of this video) we found this vendor and we have also had good luck with purchasing via Amazon vendors over other third parties in case a return is required:

Additionally, we also suggest replacing the silicone tubing too as it can degrade over time and it can be affordably sourced here:

To insulate the anode and cathode we used a high grade silicone adhesive (do NOT use the cheap stuff or household variety):

Of course safety is a big concern and if you undertake this project please understand accept this at your own risk and there should be several initial steps taken:

1. Unplug the machine from mains voltage.
2. Drain laser tube of water as best as possible
3. Ensure the high voltage power supply is discharged (see video)

Care should also be taken NOT to break the old tube and especially the new one as they are VERY fragile! This also required increased care when swapping or replacing the silicone cooling tubes.

Replacement of the Zip-Strips, you will notice I did not replace the Zip-Strips (cable ties to some) at the end this is because they “appeared” to be used for transport so the wires did not come loose during shipping. Since this was not the case for use we felt is was not worth the risk to the tube re-apply these as everything you do that tube risks a crack and is very fragile.

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