Thanks to the Openbuilds fairshare program, the laser power meter needed for this experiment has been provided. I have almost completed designing the testing procedure to determine if running a CO2 laser tube at low mA actually prolongs the life of the tube vs running at high mA. The hypothesis is that while running at high mA, the shortened tube life is made up by the increased mm/s higher mA would allow. I have 2 identical K40 laser cutters to run the experiment on, so the data collected should be fairly accurate. This will be a long term project as the tube life may be in the hundreds if not thousands of hours of run time. But I will provide weekly power outputs for both variants, and hopefully we can see an emerging trend quickly.
First update, February 17, 2017
So I received my laser power meter today. I tested the tubes in both of my K40's The one registered at 29W at full power, which I fully expected to see a low value, but what shocked me is that the second one was actually 42W at full power. Throws a wrench into my plans to compare tube power/life vs. high/low mA settings. Does any one have any ideas on how I can still make this work, other than replacing a tube which I can not afford?
Update - February 26, 2017
After pondering the issue of why the tubes were so different in power, I did a little investigation into possible reasons and found that the lower power tube was not getting a full 5V off the pot. Replaced the pot and both tubes are now within one watt of each other with one being 42W and the other is 41W. So now the testing can actually begin. I will post results on a monthly basis (but collecting data on a one week at a time schedule)
Update - March 11, 2017
This weekend marks the beginning of testing for the two K40 laser tubes. Will post results once a week, then average 4 weeks at a time for 13 - 4 week entries. Will graph and analyze the 52 entries, or until one of the tubes degrades to the point it will not operate anymore.
The testing format is as follows:
1. Test Tube 1 and Tube 2 for power level in Watts, record wattage, cooling water temperature. Run design file on both machines, Tube 1 at no more than 10mA, and Tube 2 at 28mA for cutting operations, for raster on Tube 1 no more than 5mA, Tube 2 at no less than 20mA . Record time rastering with wattage setting and time cutting with wattage setting. At the end of a week, combine all tests for that week and create average values to record in the weekly log chart. At 4 weeks, average the 4 weekly entries to get a monthly average.
I realize that a static testing procedure would make it easier to control and manipulate values, however, I can not run 2 tubes till they fail, and not have any products to show for it. Unless someone or a group of people and companies are willing to fund 2 replacement tubes for the K40. If funding becomes available, I will definitely use static test files to save wear and tear on the motion components, as well as allowing for more accurate data logging.
CO2 Tube life expectancy experiment - Sponsored in part by Openbuilds
Hypothesis - Running CO2 laser tubes at high amperage may shoirten tube life in number of hours, but will be made up for by the increase in actual inches engraved/cut using the higher power. This is a long term experiment, so the build status will remain as "Build in progress" until the experiment has been completed.
- Build License:
- CC - Attribution - CC BY
Reason for this BuildAs there has been much conjecture on the best way to get the most life out of a CO2 laser tube, I figured it was time to get some real empirical data to draw a realistic conclusion from.
Inspired byThe entire maker movement, especially the open source ecosystem.