assmbling a co2 laser for my shop

I only burn wood. or stone products. pvc bad for me AND laser. I did try a spot. eeew. i was responding to the other guy who cut a four inch pvc with his.

Yep, gotta be careful and ensure proper fume extraction when you cut plastics.

If I remake or tweak the setup in the future I'll see about getting a coolant reservoir they use in PCs and put a bleeder valve on it as well. Should make things a hell of a lot simpler. I went for the absolute lowest cost and simplest design.

My 15W tube diverges pretty fast. I haven't done a proper measurement of it, but at about three meters out it is no longer able to ignite cardboard even when given a LONG burn time.

:san:

Sigurthr said:

Yep, gotta be careful and ensure proper fume extraction when you cut plastics.

If I remake or tweak the setup in the future I'll see about getting a coolant reservoir they use in PCs and put a bleeder valve on it as well. Should make things a hell of a lot simpler. I went for the absolute lowest cost and simplest design.

My 15W tube diverges pretty fast. I haven't done a proper measurement of it, but at about three meters out it is no longer able to ignite cardboard even when given a LONG burn time.

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in your case a glass decanter and fishpump will suffice..i bet you could use a small desk for your setup or make a bookshelf that's above your work surface and the head shoots the beam downward like mine or periscope it down if you want it horizontal

if the tube goes it won't get me.

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Strangely enough I've heard that before Like I said, cheap Chinese PSU's aren't usually current limited. Have you seen how far a 20Kv high frequency arc will jump?

Your life your choice I guess but these things aren't pretty laser pens. From what I understand a 5W laser in the pointer world is something special, a 100 watt laser in the industrial world is an insignificance.

stay safe

best wishes

Dave

I've tested the psu from lightobject that I have and it is indeed current limited with rock solid current regulation. For a cheap Chinese psu it does well.

Sigurthr said:

I've tested the psu from lightobject that I have and it is indeed current limited with rock solid current regulation. For a cheap Chinese psu it does well.

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Hiya Sig,

A lot of Marco's stuff are the Japanese made variants, great kit (unbranded sony components most of the time) some of the cheap Chinese are total tosh I've seen 80's sold as 120's and 60's sold as 40's.

Same with Tubes, some are truly dire.... EFR are my current rage, fantastic life and TEM without the quick fall off that RECI's have. II-VI IR lens and mirrors in them and German Heisner glassware (also in theory refillable but can't say I have ever bothered).The ZX series really are the beasties
Of all the lasers I have one of the smallest is my favourite, a 50 watt Diode Pumped SS YAG fitted in a 300 x 300 Galvo system, peanuts power but the run speeds are awesome

At the moment in the UK we have almost no restrictions on high power Lasers, (I'm sat next to a 7Kw machine) but if too many cheap tubes get spannered into overgrown homebrews that will change pretty quick I would think.

best wishes

Dave

I changed my coolant to antifreeze. i found a plastic large mouthed oil collection can for the reservoir. the pump sets inside the reservoir.. I did this because mosquitos were using my reservoir as a breeding pool. aaaaaak! another improvement i made is that the shop vacuum blows down over the optical head and work surface to keep smoke away AND cool the head. befor the head was getting way too hot. now i can cut 3/16 paneling nicely.

I too have an EFR 60w tube (unfortunately not a ZX model) and a 80w psu from the same company in beijing. It has a molybdenum mirror.
There's that lady Lei, who is very responsive and answered all of my questions.

Spooky said:

Hiya Sig,

A lot of Marco's stuff are the Japanese made variants, great kit (unbranded sony components most of the time) some of the cheap Chinese are total tosh I've seen 80's sold as 120's and 60's sold as 40's.

Same with Tubes, some are truly dire.... EFR are my current rage, fantastic life and TEM without the quick fall off that RECI's have. II-VI IR lens and mirrors in them and German Heisner glassware (also in theory refillable but can't say I have ever bothered).The ZX series really are the beasties
Of all the lasers I have one of the smallest is my favourite, a 50 watt Diode Pumped SS YAG fitted in a 300 x 300 Galvo system, peanuts power but the run speeds are awesome

At the moment in the UK we have almost no restrictions on high power Lasers, (I'm sat next to a 7Kw machine) but if too many cheap tubes get spannered into overgrown homebrews that will change pretty quick I would think.

best wishes

Dave

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Careful with the choice of antifreeze, some of them attack the resins that hold the water chambers on to the tube.50ml of sterilising solution (used on baby bottles) like Milton works well to keep fungal growth down without causing power issues that some anti freeze can.

60 watts will cut 6mm / 1/4 inch ply pretty well if they are set up correctly (with a 50.8 focal)

Also be careful with head cooling, uneven cooling can and does shatter lens's.

It has a molybdenum mirror

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80 watt and above all tend to use Moly mirrors, the gold coated silicon and glass while better reflectors tend to get a little mucky then shatter with heating from the beam. Moly is quite safe in 3mm thickness up to 1,000 watt systems (and don't shatter if you drop them)

EFR are great and tend to be really stable, RECI's tend to give huge overpower to start with then drop off after about 3 months. The "150" watt RECI is sold as a 150 (peak) but usually ends up giving about 125 to 130 after a while (it's 1650mm long so it's maximum stable power can't be more than 130) (the 150 is 1850mm long)

It does get annoying when you realise the Tube is sold as 150 when hit with 32 Ma but the warranty is invalid if you use above 28Ma (and starts from the date of manufacture NOT sale or installation).

I put 5,000+ hours on an 80 watt F series EFR and it cuts the same as the day it was installed

best wishes

Dave

phenol said:

I too have an EFR 60w tube (unfortunately not a ZX model) and a 80w psu from the same company in beijing. It has a molybdenum mirror.
There's that lady Lei, who is very responsive and answered all of my questions.

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can you tell me what the efr are? and zx? as I'm a woodworker..not a machinist. I have this set up like tools I'm familiar with.

Bejing EFR are the company that manufacture the tubes,

The ZX series (otherwise known as the ZN) use zirconium plated electrodes to extend life and cut down electrode burn back. The ZX start at 80 watts and go to 180 watts,
The F series are their more run of the mill tubes and have a lower lifetime , they are also longer for a given power output but again give very stable figures.

EFR use German Glassware and US made lens's and are mid range between the cheap Chinese rubbish and western made stuff like Coherant and GSI.

best wishes

Dave

I've seen these on youtube, they look incredible! They only go in short bursts though, is that because if they leave them on for too long they can explode?

Errr Gas CO2 tubes can run for hours or days, I often run mine for 6 to 8 hour runs without stopping, they do require water cooling though, without it the tubes can fail in a matter of seconds from thermal cracking of the internal optics.

Gas CO2 tubes of this type aren't toys, they aren't pointers and emit no visible beam but can damage or destroy eyesight in a split second. (the blink reflex won't work as it is not visible light)
They run on voltages of up to 45,000 Volts at 30 to 35 Ma, the focussed spot can instigate temperatures in the 10,000 degree F range in some materials.

A cheap DC Chinese tube in the 60 watt range costs about $150
A DC GSI 200 watt tube costs in excess of $24,000

In the last 11 years I've never seen any laser explode, I have however seen fatalities caused by the associated equipment they use.

best wishes

Dave

Whoa fatalities? Crazy, it's really interesting how far we have come in this world as far as technology that can blind you in an instant.

Ill just keep fluid in her, hands off the wires, the goggles on. and my fingers out of the beam path or out from under the optical cutter. and air cooling on the head. And she will serve me fine

Ill just keep fluid in her, hands off the wires, the goggles on. and my fingers out of the beam path or out from under the optical cutter.

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Be very aware of a couple of things Truss, Backscatter can come unexpectedly and you NEED a path to earth for the HV end of the tube to cover tube failures and arc outs. A heavy gauge copper bonding strap will do it mounted within 1 inch of the HV connection, it will also find any insulation leaks without the current building to potentially fatal levels when it has nowhere to go.

Without it you are risking your eyesight and your life (and that of those around you) while a belt from the HV end at 20Kv (25 or so Ma) isn't going to kill instantly it can cause cardiac arrhythmia which often has the same end result. (most of the small Chinese PSU's can poke out a LOT more power than they are rated at, a 100 watt potential from a 60 watt supply isn't unusual)

Comparing a 5 watt IR diode laser to a 60+ watt gas laser is like comparing a Estes toy rocket to a Saturn 5. The power density these things can generate is truly massive in comparison !

best wishes

Dave