[herby08]

Hi robin
one more sugestion to connect your new tube this is from a big laser tube manufacturer.
you should against the way how the most machines come where the water connection goes in at the positive side and exit at the negative side , thats wrong it should be the other way around and the tube should be a bit slanted towards the exit side by just turning the tube a bit.
the reason for this is that the most heat is generated at the beam exit side of the tube and there should the cooled water enter the tube. the slant is that any airbubbles what are the same way dangerous for the tube are forced out.
the best water temperature is between 19 to 20 degreeC I am driving my tube this waywith a thermostat which switches the cooling fan who is in front of a 120mm radiator which is in front of a window airconditioner unit what I have anyway because it gets pretty hot here.
greetings
waltfl

The tube and PSU are going in the bin

I have now gone paranoid about tube temperature, totally anal.

Question: I plan to add a thermal laser shut off switch shortly after the tube outlet. I can switch at 60 or 70degC (140 - 160degF). Which would you use?

I've also ordered a radiator, a fan and a panel themometer.

I dug out a flow meter from my junk pile, then decided it would be much easier to make a little pot with a hole in the bottom. If full it pushes down on a microswitch and gives the laser an okay to cut. I can 3D print it and make it integral with the hose clamps.

[Robin Hewitt]

one more sugestion to connect your new tube this is from a big laser tube manufacturer.

Hi Walt

Coolant in hot end first, keep as close to room temperature as possble :cheers:

A 120mm radiator and fan is enough? I don't have air conditioning, hot weather is rarely a problem here.

This 50% laser power loss at 40C sounds tricky for a consistant cut, but at least I now know what to expect. Are there any other newby surprises waiting to catch me out?

I notice people are motorising their table height. I am assuming a manual adjustment to get the focus is enough if I only cut sheet, but my assumptions about lasers have not been very good. 60C became 40C and now it is 20C

Robin

[Exsecratio]

100% subjective on your current ambient conditions.

As are most of the posts Dan it surprises me when people think they can change the laws of physics because they simply don't understand them

Robin, "Things", numbers are pretty much bang on the money I'll bet there will be somebody along soon who will argue with this

it is still a catalyst.

but then again they likely have never dropped Sodium metal into water let alone have the ability to understand Raman Spectrum analysis of CO2 as a gas

If you want to have your laser working stable for long time you MUST keep stable temp. 21-22C. No more, no less.

As it happens Cine, if you want your laser stable and for a long time you should run it at -28.88 Celsius but very few people have the materials or equipment to do that, anything else is a trade off of cost over effect.

As quite a few people will be aware, scientific analysis has no elements based on the validity of opinion, in fact science specifically places no weight at all to the opinion of the proposer and only theory that can be expressed in numbers or data values really carries any weight. Anything else is anecdotal at best

best wishes

Dave