Soldering CO2 Laser Tubes

[Mrebeiro70]

My engraver arrived with a broken tube and a new tube will be here tomorrow. While I've been waiting I've been practicing the installation on the old tube, but I can't get solder to stick to the metal posts on the tube. First I tried my little 35 watt iron, but that only unsoldered the wires from the posts, but couldn't resolder the wires back onto them. Solder just wouldn't stick.

I had the posts red hot using my resistance soldering unit and still the solder would not stick. What's it going to take to solder the new tube? I've watched that video on the Rabbit website that shows the guy just touching his iron to the post and the wire just solders right on no problem?
I keep hearing how this solder joint has to be perfect with no burrs or all hell could break loose, but I can't see how a neat job is going to be possible in this situation. Thanks

[lamicron]

They use to roll apiece of wire to the post, after you put the soldering to the wire and heat it over the post, when tyou get the new tube be carefull not toheat it to much or too long( in the video is 3-5 seconds)or you can broke the tube.
I dont know if is it possible to connect it with some plugs to avoid this risk

[Dan326]

We have a 100w laser in our shop and had the same solder problem. We made brass attaching clamps. We drilled and taped a piece of brass and soldered the wire to it. It has been in operation for six months now with no troubles.
Dan326

[Mrebeiro70]

Originally Posted by lamicron They use to roll apiece of wire to the post, after you put the soldering to the wire and heat it over the post, when tyou get the new tube be carefull not toheat it to much or too long( in the video is 3-5 seconds)or you can broke the tube. I dont know if is it possible to connect it with some plugs to avoid this risk

Thanks. Last night I came to the same conclusion. You have to wrap the bare wire around the post and then solder. The solder doesn't actually stick to the post, but still locks the wire in place. I think this is how the wires are so easily soldered on and off as in the video.

[MonoNeuron]

Hi,
I used what we call here in Aus a "BP" connector for joining 2 wires together. Electricians use them for household wiring and should be found in any hardware store in any country. It has a screw inside a brass thick walled tube with an outer plastic insulator. One type is for active/neutral having 1 screw and the other type is an earth one having 2 screws. I used the earth type, 1 screw for the wire and the other for the metal post. Just tighten the screws gently and firmly. I break the outer plastic off first then connect then wrap with insulation tape. It's very easy.
Rich

[lamicron]

Mononeuron, Thats the easy way, didi you test it already? If it works thats the best solution, i know some people that had broken the tubes with the heat.
ANYWAY ! BE CAREFULL , BE SURE TO ISOLATE IT VERY WELL, 20.000 VOLTS THERE!!!

[Micheal Donnellan]

Originally Posted by MonoNeuron Hi, I used what we call here in Aus a "BP" connector for joining 2 wires together. Electricians use them for household wiring and should be found in any hardware store in any country. It has a screw inside a brass thick walled tube with an outer plastic insulator. One type is for active/neutral having 1 screw and the other type is an earth one having 2 screws. I used the earth type, 1 screw for the wire and the other for the metal post. Just tighten the screws gently and firmly. I break the outer plastic off first then connect then wrap with insulation tape. It's very easy. Rich

Anyone else use a method like mononeurons. Sounds very fast and handy but them connections are not made for 20,000 arching volts. If other people has success longterm with this method I might use it my self as broken tube from solderng is expensive mistake.

[MonoNeuron]

Yep, Tested and worked fine. If the wire is thin like some of the negative wires then just fold it over and solder the wire end so it is twice as thick then screw it to the BP connector. It may be 20K volts but it is in the milli ampere range. Anybody had a shock from a car ignition coil? I have had many as a mechanic and they are from 20K to 40K. Not nice but it's more of a scare than anything else. I can hear all you puritans out there saying "this guy is mad" but I bet none of you have had one on the family jewels while reaching over the car and your package is too close to the fender when you inadvertently stray near a spark plug. :-)
I'm still here though. Don't know for how long!!!!!!
But seriously. Take basic precautions and insulate the connections and everything will be okay.
I am helping, Aren't I ????????
Rich.
PS. When your package is bitten by high tension electricity the ground rushes up fast to stop you falling too far. Mother nature at her best.

[MonoNeuron]

One other thing. Just look at the wire sizes coming out of the electrical thingy that powers the laser. One is small and the other is small as well but with a lot more insulation. That should give you a hint on what sort of connectors that can work. A TV set has clip on connectors on the vacuum tube for the high tension wire so I can't see why a screw and brass tube won't work if they are secure enough.