Preface: This document covers some special considerations, warnings, and best practices to ensure your laser operates in an environment where continued performance and reliability are maximized.
Always observe best practices for safety and be sure all systems are de-energized before performing any maintenance, adjustment, diagnostics, etc...
Equipment Environment Considerations
Ideally you should operate your machine in a space that is between 60 and 80F, that is dust free with adequate ventilation and non condensing humidity.
Setting your Thunder Laser up in a suitable temperature-controlled, dust-free, moisture-free, level, stable surface (a level concrete floor) with the recommended extraction is critical to the ongoing performance of the machine. It is also a warranty condition.
Laser Source Cooling System Types
We use a few different laser sources in our machines and depending on the source type, freeze mitigation and ambient temperature strategies will vary based on the source type.
Air Cooled CO2
The RF tubes in the Odin, Bolt and Nova Plus series machines are air cooled. On air-cooled laser tubes, fans blow air across the heat-sinks of the tube to cool the tube. The system temp cannot go lower than the ambient room temperature. Freezing is generally not a concern since water is not involved. Electronics however do tend to operate better at above freezing ambient temperatures. Please refer to the manual for further guidance on ambient air temps.
More on RF Excited CO2 Laser Sources HERE.
Water Cooled CO2
The glass tubes in the Nova series laser are water cooled and are sensitive to sub-freezing temperatures. The system should ideally run with the water between 15C and 25C. If you have sub freezing temperatures outside, then you need to take precautions to prevent damage to the laser tube. (Damage to the laser tube from freezing/Thermal Shock is not covered by Warranty)
Electronics however do tend to operate better at above freezing ambient temperatures. Please refer to the manual for further guidance on ambient air temps.
More on DC Excited CO2 Laser Sources HERE.
Air Cooled Fiber/UV
The Aurora Series sources are air-cooled and coupled to the galvo scan heads. The efficiency of the cooling will greatly depend on your ambient temperature. Generally there is no issue with freezing temperatures since the source does not utilize water. Electronics however do tend to operate better at above freezing ambient temperatures. Please refer to the manual for further guidance on ambient air temps.
Glass Tubes - Mitigating Extreme Temperatures
Here is more information on combating extreme temperatures. We want to prevent a tube wall breach or freezing expansion. Frozen/Thermal Shock tubes are not covered under warranty. As cold weather approaches, it is time to take steps to mitigate a Glass Laser Tube failure…..Even if you live in the South. In previous years, the polar vortex has had deep freezing temperatures down in Texas.
Example of a tube that had anti-freeze but failed. The tube should not have water in the outer jacket area:
Freeze Prevention
There are a few basic ways to help protect your water-cooled cooling system from freezing.
Workspace Considerations
- Keeping the workspace above freezing is desirable. Some use small space heaters when necessary.
- Prevent cold air from entering the machine by disconnecting your exhaust from outside temperatures. Exhaust and Cold Weather
- Open the machine up so that it can acclimate to the room ambient temperature - Main lid and Tube box door at a minimum
- Be familiar with how to drain the Tube and Chiller in case of an extended power outage and freezing temperatures
Draining Coolant/Water/AntiFreeze
You can also drain the coolant system when not in use. Use the drain port on the back of the chiller and then disconnect the tubing on the back of the Laser Machine to evacuate as much coolant as possible. Pull the hoses off the machine and drain into a bucket. For faster draining, raise the machine outlet hose to be above the machine. Apply light pressure through the hose to clear any low lying coolant.
Reference videos:
Getting the last residual water out:
AntiFreeze Coolant
Warning: Antifreeze is not a SET and FORGET solution. Tubes can and will still break even with Anti-Freeze installed.
Liquids like water begin to expand as they cool down. Expanding water can crack glass if the pressure has no where to go or is not relieved.
We use pure distilled water in DC excited glass water-cooled tubes because it has a conductivity low enough to occupy the tube while 30,000 volts arcs through the tube. Additives can affect that conductivity and can damage the cooling system components, especially with long-term use.
We do have recommendations on the use of antifreeze here: Thunder Laser Approved Antifreeze
And there is more technical data on a variety of additives here: Laser Water Coolants & Additives
Run the Machine
Run the laser machine, it will warm the water up and keep the water warmer than if it is just sitting in a cold environment. Longer cuts and engraves will warm the water up.
Drawbacks of this method is there is minimal overnight protection, requires power and operator's full attention.
Heat the Chiller Water
You can actively warm the water up with a water warmer. Be sure to set the temperature setpoint of warm to below the Chiller's setpoint by at least 2 Degrees Celsius so that the chiller does not cool the water down. An ideal minimum would be 15c on the warmer.
The Chiller must be put in Constant mode with a Set point set, typically 20C, no higher than 25C.
Selecting Intelligent or Constant Mode on CW-5000 Series Chillers and Constant Mode Temperature Set Point on CW-5XXX Chillers
Do not warm the water up too warm and always make sure the water is circulating. Warm water can promote growth.
High Heat Condition Considerations
Cooling the Ambient Temperature
Keeping the ambient temperature below 80F (27c) is ideal. The efficiency of any type of heat exchanger is affected by high heat conditions. Air cooled machines will lose efficiency and have power reductions in high temperature.
Relocating the Machine
In order for your laser cutting machine to function properly, not only in winter but all year round, make sure it is stored in the correct environment. The room temperature should be between 60F and 80F with humidity between 40% and 70% and not in direct sunlight.
Additional Resources
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