Hi ,first time posting here & I was trying to align the mirrors in my K-40 as it takes many cuts to do the same work as it use to (I’ve owned this thing for a few years now ) , but I noticed when i put a piece of paper next to the laser tube & between the first mirror & fire the laser i get 3 individual burns instead of one round hole . would this mean my laser tube needs to be replaced ? or any way to fix it ?
Hi and welcome to the forum. If you are getting a distorted or multiple spots that usually means the TEM mode of the tube has shifted to a higher mode. If that’s the case then you will need a new tube. If you can provide a picture of the test fire we can confirm.
Looks like a bad tube… @NedMan what do you think?
@copperhead did you have any kind of overheat event??
What coolant are you using?
How old is tube and how hard do you run it?
Yep, looks like you have shifted to TEM-01 like Don said. Common type of tube failure as your tube ages. I had to replace my stock tube after a couple of years because of this. Higher tube temps can lead to TEM failures.
This tube gets quite a bit of use ,I’ve ordered a replacement & I’ve been using a large container for my water for cooling & that may of been the down fall .as i didn’t realize the ideal temperature was lower than room temp . Has any one tried the CW-3000 water chiller ,is this refrigerator or just a fan blowing on a rad ?
A CW-3000 is just a radiator and a fan. It can dissipate about 50 W of heat per 1 °C difference between the ambient and coolant temperatures. E.g. if the ambient temperature is 24 °C and the coolant is 30 °C, it would manage to dissipate about 300 W of heat.
With a low-power CO2 laser, the math can work out if you’re living in a colder climate.
The CW-5000/5200/etc chillers use vapor-compression refrigeration. They are actual chillers.
If you need something cheaper, see if you can find a used aquarium chiller with compressor for around $150. The smaller ones are fine for low-power CO2 lasers.
Here’s our article on the subject — we keep updating it as more information shows up, so please feel free to ask clarifying questions there.
I think I will get a larger water reservoir & or run my pump outside in a large garbage can , with the hose running at a trickle .
It’s almost everywhere a bad idea to run tap water in your tube. It generally has impurities that conduct electricity. Distilled water is a much better choice, and frozen water bottles submerged in a bucket of distilled water are great for keeping the water cool enough.
Yeah just get a 5 gal bucket with a pump and distilled water and use some frozen 1/2 litter water bottles. I like to use soft drink plastic 1/2 liter bottles because they are a bit more robust than the bottles water comes in. I’ve got about a dozen bottles in the freezer and I can basically run all day if I wanted to just by rotating them out in groups of 2.
and get a water temp device so you know what the temp is entering your tube and can adjust the reservoir as needed.
I suggest a water temp controller that will stop your laser when the set temp is exceeded.
I use this one and wire it into the water flow sensor circuit.
while you are in there its easy to add cover interlocks
Thanks for all the help ,I have my new Laser tube installed & it`s working well ,I am using distilled water & a couple of frozen pop bottles full of water keeps the water at 15 to 17 degress .