This may be a stupid question, but why was the laser attached in such a way as to require all the complex juggling of mirrors? Why not just stick it down like the spindle?

Not a stupid question at all.

Mounting a CO2 laser tube vertically does work and many have done it but it's life expectancy is considerably reduced.

Unlike diode lasers the CO2 lasers produce a certain amount of detritus during operation (some from the gasses but mostly from the electrodes). If the tubes were mounted vertically this waste material would settle on to the output coupler, burning-in, cause overheating of this component and ultimately lead to the early failure of the tube.

Various tube manufacturer's (such as Synrad) withdraw their warranty if their tubes are mounted beyond a defined angle to the horizontal.

Tweakie.

I see thanks.

Hmm it looks like you can't modify posts. Just wondering what laser you would suggest? I'm only at the stage of reading about the two types, diode and carbon dioxide. I'm reading diodes are dangerous to your eyes and I'm not sure why but apparently the carbon dioxide varieties are much more commonly used.

Given that you've got some experience using your laser and it looks like you've even replaced it once already, do you have any suggestions on which one to get? I'm looking into hot rodding my CNC machine just like you did but recommendations would be much appreciated.

P.S. Found the post modification button, I'm guessing it gets locked out after a time limit.

Because the wavelength of the laser beam is different between CO2 and Diode lasers the effect of a minor, accidental, exposure to the eyes is also different. A CO2 laser will cause damage to the cornea (similar to welders arc-eye) and this may be repairable whereas a Diode laser beam will travel through the Cornea and be focussed by the lens onto the Retina which may not be repairable. I am extremely happy to use a CO2 laser with just standard eye protection but when I use a diode laser I always wear the full goggles with an OD 4+ rating to match the wavelength of the diode.
Having said that and much to my suprise, there have been extremely few, genuine, reported cases of eye damage caused by lasers.

When I started this thread Diode lasers with enough power to do anything useful where rare and extremely expensive. Nowadays, since the advent of blue-ray players and recorders, the diode price has fallen and they now offer a much cheaper and easier entry into laser work as compared to CO2. However, you must consider the type of work you wish to do as the wavelength of the laser will determine its action / reaction upon different materials.

I have and use 3 different types of laser – Diode, RF excited CO2 and DC excited CO2 and they each have their own strong and weak points. The only thing I can suggest is that you read-up as much as you can before making the decision.

Tweakie.

(the post edit function was being abused so the function has been time limited)

Gocha. Yep reading about this stuff as we speak. Mostly forums for now, hopefully will find some good links along the way.

I can't possibly keep up with all new developments so if, in your travels, you find anything good please share the info.

Tweakie.

Pictures always speak louder than words and (as you all know) I just love pictures.
Not to everybody’s liking but this is my take on changing the pin allocation and polarity of a PWM signal on a DB25 ribbon header cable connecting my CNC machine to the controller.

Tweakie

>>Various tube manufacturer's (such as Synrad) withdraw their warranty if their tubes are mounted  beyond a defined angle to the horizontal.

   75 degrees to the vertical is the maximum allowed with SynRads.

(nice circuitry on a cable Tweak.. very tidy way to do it.)

Art


 

Thanks for the info. Art.

One thing that concerns me is that I have learned so much over the years (lots from you) that if it is not shared with others now then one day it may all be lost.

Tweakie.