Here in the UK Winter is coming and if anyone, like me, has their glass-tube laser located in an outside workshop and lives in a similar seasonal location, it is always wise to take precautions to prevent a cooling system freeze-up.

I have a 5 deg.C ‘frost-stat’ workshop heater but that could fail so my laser tube cooling system comprises Distilled water with 30% vehicle antifreeze added. The system is closed-loop and fully contained but precautions must always be taken to ensure that children or pets cannot possibly gain access to the coolant.

WARNING – If you use antifreeze please be aware that it is a particularly dangerous substance and can, even in extremely small quantities, be deadly to cats as well as extremely toxic to young children.

Tweakie.

Good point Tweakie.  Do you guys have the "safe anti-freeze"?

Brett

Hi Brett,

The 'pet-safe' product is available here in the UK but awareness to the existence of this product is sadly lacking. 

Tweakie.

Ethyl . . . BAD!  Propyl . . . GOOD!

Another image produced on Obechi using the Mach3 Impact / Laser Engraving plugin.

Tweakie.

Sexy ... I like

Hello, and thank you for this forum, which gives me a lot.
I'm French and I use a translator, thank you to excuse my bad qualities words.

A big thank you to Tweakie for your site "http://www.cooperman.talktalk.net" and for your participation in numerous forums. I learned a lot.

I realized your PWM controller and I use the program V16.2
Manually everything works perfectly.
But with Mach3, I get a varying voltage S0 to S1000 but I can not seem to have a constant voltage and frequency is not fixed on 5khtz. Which side can come the problem? Is that I made a mistake or Mach3 is that I can not solve
Thank you for helping me because I'm not experienced with Mach3

Hi Bartabac,

Some while back I did try using the Mach3 PWM output for laser control but it was not very successful. Perhaps it depends on the type / specification of PC used but I found that the small, periodic, frequency variations of the PWM produced quite large changes in laser output power. This is not noticeable when cutting but it can spoil engraving work etc. so I abandoned the idea in favour of manual control for maximum laser current.

Tweakie.

Hi Tweakie,

 Thanks 1000 times answered me so fast
Your answer reassures me because I try for several days without results
At the same time it is sad because I can not find my PWM laser.
But I still very happy with your system because I can control my 40W CO2 laser in manual low.  With a potentiometer I could not do it in low voltages. Your control installation works perfectly. 
Thank you very much for your work

For now I use Mach3 PWM montages that works more or less
"http://Http://www.sonelec-musique.com/electronique_realisations_conv_pwm_tension_001.html"
I changed the diagram 001ab R4 and R5 by 470ohm this may help some people can be.
But if someone has a solution for the PWM with Mach3 and a laser I would be happy.
In any case a very big thank you.
Continue to make me dream

Hi Bartabac,

I am pleased that you are making progress with your laser control. Perhaps you could post some pictures of your work, setup etc.

I am following with great interest the work being produced and shown by the guys in the Diode Laser thread here http://hobbycncart.com/forum/63-151-11  Really excellent work.

A couple of images I just had to try with the CO2 laser – Jeff’s train engraving was produced using GCode generated by John’s PicLaser software using the Sierra algorithm and Amator’s craftsman engraving was reproduced using the Mach3 plugin.

Tweakie.