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  • Laser Welder Gloat

    Got another new toy on the way, a 4 axis CNC laser welder!

    The laser itself is a Nd:YAG made by JK Laser in England. It is rated at 55J per pulse, .5ms to 20ms pulse length, up to 100Hz pulse rep, 400W average power. The manual says it can be used for laser welding, drilling and cutting up to 5mm metal. Fun! Great for welding odd-ball metals.

    Bad thing is it sucks power, at 240 3 phase it wants 66 amps peak. Ouch! The power supply is Two 19" rack cabinets bolted side by side about 4-1/2 feet tall and weighs in at about 880lbs (400kg). It also wants about 5 gal/min water cooling.

    It was originally bought by Tektronix in 1985 for the display division. A friend who used to work down there said when he was there they used a ruby laser to zap tabs inside evacuated CRTs. The machine has sat for about 10-12 years now. About that time the original Anorad control died and they decided to upgrade the control to something more modern. They used MDSI OpenCNC with Yaskawa Sigma II brushless servos. After spending a LOT of money on the software, drives, and I/O the management decided this was costing too much and wanted to get out of the laser welding side of things so the project was dropped. The machine has sat ever since.

    This is the software, yeah, $11,000 for the 4 axis version: http://www.mdsi2.com/Solutions/CNC_C...s/default.aspx

    The machine has an amazing amount of documentation including copies of the original correspondence between Tek and the machine integrator, Lumonics. There are two filing cabinet drawers of complete schematics and blueprints for the laser and the machine it was integrated into. Every custom part used to put it together seems to have a print.

    I am hoping I can modify it to run off of single phase. According to the schematics the power comes in and is routed to three places, a single phase transformer which supplies the DC for the control electronics, a three phase pump for the head cooling loop and two main three phase transformers in parallel. The first two are easy to deal with, a small VFD on the pump. What I am hoping is since the transformer is tapped for voltage selection I can rewire the windings for single phase operation. The output does not matter so much, it is just rectified for a 425v DC buss to charge the capacitor banks. If this does not work I have a 15HP rotary phase converter I built for my lathe that might run it.

    For the cooling I will just use a garden hose for now, it wants 2 to 6 bar at 20l/min of water. If this thing does work I will probably get a plastic 55 gal drum and use a pump to circulate from that into the power supply's heat exchanger. A thermostat would add tap water to the tank as it heated to keep the temp stable. Maybe an evaporative cooler too.

    It comes with an extra set of new lamps. Bad news is it sounds like it may need to have the YAG rod repolished. I cant imagine how much this is going to cost. It is a pretty good sized rod too, 3/8" diameter and 6.25" long.

    Oh yeah, $500.


    Lumonics laser welder by macona, on Flickr


    Lumonics laser welder by macona, on Flickr

  • #2
    DAMN that's a SCARY machine!

    /Goldfinger mode;

    "No Mr Bond, I expect you to die"

    400w average from a laser - what's the beamwidth? I can see a long haul getting it working, when you do I might want some laser cut parts for one of my bikes... What's its work envelope? But nice score, "you suck" awarded
    Rules are for the obedience of fools, and the guidance of wise men.

    Holbrook Model C Number 13 lathe, Testa 2U universal mill, bikes and tools

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    • #3
      Yep. You suck.

      They'd have to rewire half the power grid in my little town just to turn the damned thing on.

      Keep us posted. You get that bad boy running and you'll have lots of friends.
      Definition: Racecar - a device that turns money into noise.

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      • #4
        Wow. Get yourself a shark and you'll be all set!

        Comment


        • #5
          Nice find macona - you get hold of the coolest stuff.

          Diesel-generated power is relatively cheap. I'd be looking for an old genset to power that.
          Peter - novice home machinist, modern motorcycle enthusiast.

          Denford Viceroy 280 Synchro (11 x 24)
          Herbert 0V adapted to R8 by 'Sir John'.
          Monarch 10EE 1942

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          • #6
            A 20hp Phase Perfect will power that nicely

            Nice score. Take care with YAG... you can't see it coming (I worked for a couple of years with a big lab yag used for "materials testing" - imaging the beam on CID cameras to guarantee the power characteristics - late 80's...)
            Last edited by lakeside53; 06-09-2013, 10:32 AM.

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            • #7
              man you get some awesome scores!
              https://www.flickr.com/photos/csprecision

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              • #8
                Go ahead and invest in the 55 gallon drum and a pump because its very rare for a municipal water supply to flow that kind of volume at 0 pressure, unless you have a big meter, say 1 1/2" or bigger. I would be surprised if you could get 5 gpm at 30 psi (your minimum pressure) sustained.
                James Kilroy

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                • #9
                  Water around here is about 60PSI and I get about 8-9 gal/min at 0psi. It should do with trick. It was ran off city water in the past.

                  The machine has lots of extras including a few pairs of goggles and a IR viewer set.

                  Dave, I am not sure of much of anything at this point. It does use a 3/8" rod so the initial beam is at least a good chunk of that. Bit it should be a pretty tiny spot, it does have a beam expander.

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                  • #10
                    Neat new toy

                    Looking at the power requirements and given its age, It was easier to use 3 phase rectifiers 'cause they couldn't find suitable high current rectifiers. I addition to the fact that they never envisioned that being installed in your garage... :>)

                    Most likely, just as with a 3 phase /1 phase welder you could just drop the peak pulse rate by 33% or so and keep on welding...sure will be fun to try.

                    paul
                    paul
                    ARS W9PCS

                    Esto Vigilans

                    Remember, just because you can doesn't mean you should...
                    but you may have to

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                    • #11
                      If I just went with trying single phase I think it would be limited to about 1/3 output, if it worked at all. It does have undervoltage detection. Using single phase you would be only using 1/3 of each transformer.

                      I am probably going to have to rig up a power supply to reform the main tank caps. They have not been charged in forever.

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                      • #12
                        re 3 phase: I would think that the load will try to draw the same amount of current regardless of what is suppling it. While it may well be to much for the winding and the rectifier, the demand is the same. ie the load impedance... 10 ohms is 10 ohms. So the voltage won't be low if you give it long enough to charge, but as you observe the safety circuits may not like it.

                        The reforming would be a really good idea.
                        See:
                        http://www.vcomp.co.uk/tech_tips/ref...eform_caps.htm
                        http://www.qsl.net/g3oou/reform.html
                        http://www.nmr.mgh.harvard.edu/~reese/electrolytics/#reform
                        http://www.angelfire.com/electronic/...store_cap.html

                        Wow. First four search results... and to think that I used to just hook them up to a 12v battery...

                        paul
                        paul
                        ARS W9PCS

                        Esto Vigilans

                        Remember, just because you can doesn't mean you should...
                        but you may have to

                        Comment


                        • #13
                          Originally posted by macona View Post
                          Got another new toy on the way, a 4 axis CNC laser welder!
                          YUP! I like your methods. I didnt read all the post or replies. Some good stuff though what I did pick up on. Fun toy.

                          So Ill comment on why does it have a large current demand? I dont see it with a 400W tube. Lazing tubes are not too unlike RF tubes other than one likes AC and the other DC. I get that you are loosing some with the conversion from AC to DC. It is a DC tube right? I dont know. But for a 400W output Id like to know where the other power is? Almost 16kW with 66amps at 240.

                          I think the rotary unit will supply it. If its a DC machine it wont run like an inductive load but sure as heck wont be like a resistive load (Like a welder) which wont work. The rotary should do it. I have an old Emco lathe that was said to not like rotary 3ph. Well I just bought a large enough one so it couldnt complain. And it doesn't. Runs just fine and the big Baldor 15hp 3ph motor doesn't even know it has a load on it.

                          Kinda funny though my home grown 5hp rotary via Art Volz. Nice guy. We were both metal shaper fans. We talked a lil. Anyway, this lil 5hp motor kinda likes to "grind" when the bridgeport in switched from forward (4000rpm) to reverse. You know, sounds like the windings want to leave the housing LOL. I dont do it often and I actually get more chatter from the contactor switch. Other issues.

                          I thought about running an additional string of three 6ga lines from my 15hp unit but dont need to yet. Its serious overkill for my lil garage.

                          It will be nice to see you get this beast powered up. Ummm? The shades? They arent so you look cool. They are there so you can keep looking. UV is a bear JR
                          My old yahoo group. Bridgeport Mill Group

                          https://groups.yahoo.com/neo/groups/...port_mill/info

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                          • #14
                            Paul, thanks for the links. I got to figure out what I am going to do for a 450v power supply to reform them. Maybe a simple voltage quadrupler and a variac. Or I could put 4 of those solyndra solar cells I have in series and put it outside! That ought to bring the bank up nice and slow.

                            JRouche, This is a YAG laser, flash lamp pumped crystal rod. Lots of wasted energy in heat, thats why it wants 5 gallons/min of water to keep it cool. Dual flash lamps, one bank of caps for each one. About 2 ga wires to the head.

                            When I figure out how I am getting this thing home I will know more. I will also post some more pics of the power supply. The input rectifiers were pretty substantial though I really was not paying attention to that when I was disconnecting the power supply from the rest of the machine. I think it used some larger bolt down half bridge modules for the main rectification.

                            Comment


                            • #15
                              Originally posted by macona View Post
                              Water around here is about 60PSI and I get about 8-9 gal/min at 0psi. It should do with trick. It was ran off city water in the past.

                              The machine has lots of extras including a few pairs of goggles and a IR viewer set.

                              Dave, I am not sure of much of anything at this point. It does use a 3/8" rod so the initial beam is at least a good chunk of that. Bit it should be a pretty tiny spot, it does have a beam expander.
                              Apart from your eyes I would also be worried about getting holes burnt through your head or body!

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