The laser has been re-relocated to its new home at the new permanent location of Colab, at 4667 Mission Gorge Place, Suite A, in San Diego. Thanks to the great work of Jolly Rancher and many other volunteers, the laser has its own air-conditioned space with all-new exhaust ventilation to outdoors. The laser tube has been re-installed. A few finishing touches remain before the laser can be operated. After that, a thorough alignment and tuning is all that should be needed before the laser can return to regular service.
That is, if nothing else goes wrong. One of the finishing touches planned for the work session on Tuesday (April 8, 2025) was to refill the water cooling system that keeps the laser tube cool during operation. After adding the first gallon of distilled water to the chiller, we had about half a gallon of water on the floor. Investigation revealed that one of the tubes inside chiller had become brittle with age, and cracked in several places. Most of the tubes in the chiller are silicone and are still in good condition, but that one tube was clear polyurethane. That tube serves as a sight glass to judge the water level, so it has to be transparent. I didn’t find a local source for polyurethane tubing, but the blessedly nearby Home Depot was able to supply clear vinyl tubing in the same size. With the new tubing installed, the chiller no longer leaks. That little side quest consumed the remaining time in the Tuesday work session, though. The next step is to run the cooling water into the laser tube.
Speaking of the laser tube, it was practically new when Covid hit, but laser tubes of this type also have a limited shelf life. Five years later, it’s possible that the tube won’t work at all, or won’t work as well as it did when new. Once we have the cooling water working, we will test it and find out.