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Anne Venter
12-04-2016, 3:42 AM
Hi all. Let me jump right in. I have a 100watt laser cutter. Chinese model Ruijie. I have been cutting with it just over 2 years and it's been working like a dream. A few days ago i switched on and prepared to cut something, only to notice that it was cutting as if set at a very low wattage. After testing and retesting it was still the same. If I pulsed it there was nothing. I contacted the company and explained my problem. He suggested replacing the tube. This I did, the new one had little pins on either end which I had to solder the electrics onto. All done and water connected, I proceeded to switch on. It tripped the plugs breaker and I switched everything off. After putting the breaker back up and switching on again, everything came on, meaning blower fan and extractor fan and chiller. But the control board is dead as in all control on the bed itsself, if that makes sense. Its as though I haven't switched it on yet. Now I am told to replace the power supply, which I assumed is the biggish box with the fan on? But he tells me it is a small little box. I am very confused and have ordered what he advises but am still not sure if I am doing the right thing and if I have damaged the tube in any way. If anyone could give some advice I would appreciate it greatly.

Mark Taylor2
12-04-2016, 1:08 PM
If it's a CO2 and a glass tube, soldering was very bad. The heat destroys the seals and the CO2 will escape.

Bill George
12-04-2016, 1:43 PM
If it's a CO2 and a glass tube, soldering was very bad. The heat destroys the seals and the CO2 will escape.

Ditto, those wires coming out are tungsten (I think) and can not be properly soldered, you might get it to stick but it won't bond correctly. Mine had a mechanical screw type connector to hold the wire on.
My guess new tube and PS are next on your list.

You said little wires on one end, one end is the HV + Red and the far end of the tube the HV black or ground wire connects to. If you have them Both on one pin, that is bad news. A picture is worth a thousand words.

Dave Sheldrake
12-04-2016, 2:44 PM
Pictures needed, without them you stand a very good chance of electrocuting yourself

John Lifer
12-04-2016, 3:43 PM
If you will go to Rdworks learning lab on Youtube. There is a video by Russ that shows him connecting a new tube.
https://www.youtube.com/watch?v=NzbqN8m7hGM
Should be this one. He had Pins on his tube. No, no soldering. He actually just wound the wire around the tube and then put silicone glue on it. Go buy another tube and try again!

Dave Sheldrake
12-04-2016, 4:05 PM
The safer way is to solder an expansion spring with a 1.5mm ID onto the wire then reverse screw the spring onto the electrode (It will grip and provide a good joint)
Glue isn't the best way to secure a high voltage circuit.

Mark Taylor2
12-05-2016, 12:52 PM
The safer way is to solder an expansion spring with a 1.5mm ID onto the wire then reverse screw the spring onto the electrode (It will grip and provide a good joint)
Glue isn't the best way to secure a high voltage circuit.

Dave, where would one find those springs? I was thinking wire nuts but I don't think the plastic insulation would be sufficient.

Bill George
12-05-2016, 1:09 PM
Dave, where would one find those springs? I was thinking wire nuts but I don't think the plastic insulation would be sufficient.

I think a wire nut would work, remember the insulation is a mote point as it should be a couple inches away from anything conductive. I used a split bolt connector, you can find various sizes at a home improvement electrical department. Remember all you want is snug, do not over tighten. Then you can put some RTV silicone sealer over it and let dry.

When I was in the trade they made wire nut springs without the insulation, you just twisted over the bunched together wires and snapped off the little tab, added your own HV tape or whatever.

Anne Venter
12-09-2016, 10:46 PM
Thanks all for the response. I have put the new 24v ps in and everything is on again. I still have the 80w tube and 100w psu in. When i pulse the machine though there is no stream coming out at the first mirror. If i hold the pulse there is some burning on the wood. The supplier told me that since I am using a lower watt tube with the higher watt psu i must be careful not to go too high since I could damage the tube. Is it possible for the psu to have lost its power to such an extent that it will work just a little. Or am I doing something wrong. My mind tells me it either works or it doesn't. Since a new psu is so pricey I need a way of testing mine first.

Dave Sheldrake
12-10-2016, 3:02 AM
A 100 watt PSU will kill the 80 watt tube, it's the wrong voltage and current

Dave Sheldrake
12-10-2016, 3:03 AM
Dave, where would one find those springs? I was thinking wire nuts but I don't think the plastic insulation would be sufficient.

Pretty much any hardware store Mark, just basic steel springs with the correct (ish) ID