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Laser Welder Gloat

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  • macona
    replied
    Its been a while since I posted about this guy. Between the thermal cameras and the vacuum system I have been preoccupied.

    So, I now have the drive and power panel assembled. Hooked it up to the servos on the machine and it all works controlled through linuxcnc. At least I can move stuff around. I have not messed with the control of the laser from linuxcnc, that can wait. Pick below of a semi finished board, it has been cleaned up with some wire molding to keep things somewhat in place.



    I went through a couple different designs for the control panel, I got a 24"x30" cabinet and had a control panel cut out for it on the laser at work as well as a bulkhead for the servo cabinet for the cables. Not cheap, about $130, but a lot easier than trying to make it myself. The left side will hold the 19" rack mount 8U PC display and the two 4U controls for the laser.





    I plasma cut the openings in the JIC cabinets this weekend and tried to powder coat the control panel and bulkhead plate. The powder went on thin and I am just going to have to paint it.

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  • lwalker
    replied
    Just as well. I took a look at them and they're all IDC type. I thought they were PC board mount. Oh well, guess I'll hang on to them for 10 years like all the other junk around here ;-)

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  • macona
    replied
    I was going to make some pcb breakouts for the centronics connectors. Then I found I can get 36pin extension cables for $5 shipped from Dell. No contest there. Just cut the cable and wire into the opto22 terminals.

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  • lwalker
    replied
    If you are DIY'ing any breakouts and need Centronics connectors let me know. I purchased a big bag of mixed connectors on eBay and it came with about a dozen Centronics types I have no use for. Yours for the price of mail to wherever you are if you want them.

    Lyndon

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  • macona
    replied
    Got the drive panel wired mostly wired up short of IO for the control panel and the breakout for the laser. I ordered up a couple parallel port extension cables to tie into the laser. The laser controls terminate in generic Centronics 36 pin connectors so that makes it easy.

    I took the panel and computer over to my friends place where I am keeping the laser and hooked it up. It worked. Of course all the motor directions were backwards but that was an easy parameter change. Everything homed out like it should. I need to find a better GUI for linuxcnc, the ones that come with it are awful.

    The Mesa boards are working out great. The one that ties into the opto-22 rack worked out simpler than I though, any port can be input or output and it is just a matter of reading to writing to that "pin". Now I need to get a friend of mine to write some code to make up some custom M codes to control the laser.

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  • macona
    replied
    I got the board set over a month ago and ended up also getting a 7i69 board that will allow up to 48 more points of IO and will tie directly into Opto22 IO Racks via 50 pin flat cable.

    Getting a working computer system together has been hell. The first setup (Pictured above) had issues, I could not connect to the mesa daughter boards. Turns out there was something strange with the PIII single board computer in the case. For some reason when set to a 133 mhz buss the 5i25 card became unhappy. Only this card though, all the other cards, USB, WiFi, and firewire were happy. This took a while to figure out and started a hunt for a board that would work. I ended up finding a P4 SBC that would fit in to the existing backplane on ebay and it is working the best out of all the motherboards I have tried, getting about 10000/10000 under the latency test after a couple days running it. It was not without problems though. The board had bulging caps which I replaced (Damn RoHS solder) and then the thing would lock up linux after about 8 hours and I was getting a SMI pulse. I reset the BIOS to fail safe settings and all the problems went away, even the SMI issue.

    I was hoping I could use a firewire c-mount camera I have to add computer vision to the machine but it really kills the machine when displaying video. Linux has been a pain with that. So many little things with firewire and simpler things like the touchscreen.

    So now that I know my machine will actually work I have started putting the panel together. I ended up ditching the old roll around console that the guy was using before me. I got a 2'x3' JIC cabinet to put everything in. This will hold the computer, drives, and all the IO stuff. This is pretty much everything screwed down, I need to start wiring next.


    Laser welder drive panel by macona, on Flickr

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  • wendtmk
    replied
    Macona,

    Once you get this thing up and running, have you considered making CRT repairs? I've got a Tek SC503 CRT that has the two heater strip attachments separated from the pins to the plug. Trying to find a replacement SC503 CRT has been like pulling hen's teeth. It's a small storage scope that plugs into the TM500/5000 mainframes.

    Mark

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  • macona
    replied
    Yes, Cant remember which days. Not anything like it used to be. I did get a nice 1050mhz rf signal generator though last year. Now that I am working again I cant get down there.

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  • ligito
    replied
    I used to get some nice stuff from Tektronics Rams warehouse.
    Are they still in business?

    Leave a comment:


  • macona
    replied
    Ive been waiting on the guy at MDSI (OpenCNC) to help me get the darn servo loop tuned and have not heard anything from him. So at this point I am going to dump OpenCNC and go with LinuxCNC and use the internal positioning control that the drives have. This allows me to just send them step/dir signals like with a stepper motor. I am ordering a Mesa 5i25 with the 7i76 breakout today.

    Found a nicer computer to replace the existing one with. It is a Advantech 19" industrial PCI/ISA backplane case with a PIII 933mhz SBC. 15" touchscreen with a membrane keybd and touchpad. Seems to work fine, with things tweaked it runs the latency app at about 21000 ns. Linux is fighting me with the monitor and the touchscreen. The monitor does not return EDID info so linux wont go past 800x600 no matter what, even after adding the modelines for it. I found a EDID emulator that goes in between the video card and display to give it the info it wants.

    The touchscreen seems to just be a driver issue.


    Advantech 19" rackmount by macona, on Flickr

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  • browne92
    replied
    Originally posted by darryl View Post
    Macona, you get to play with some interesting stuff. By the way, I've found a much less expensive way to set paper on fire- something called matches.
    Sure, but they ain't near as much fun!

    Leave a comment:


  • darryl
    replied
    Macona, you get to play with some interesting stuff. By the way, I've found a much less expensive way to set paper on fire- something called matches.

    Leave a comment:


  • macona
    replied
    Last monday I took the water pump apart to see what I could do about the mechanical seal, the only sources for the OEM seal are in the UK and at probably over $100 shipped I figured it was worth a try to see if I could find a replacement. It is a pretty standard seal, Aluminum oxide on one side, graphite on the other. 12mm shaft and a 26mm bore on the casing. I found a seal that matched these dimensions on Amazon for $6.20. What do you know it worked! I also changed the motor bearings while I was at it, they were pretty dry.

    I knew the output coupler was pretty toast and I had never checked the high reflector. I found a new HR for an ESI laser that I had in one of my parts bins. Right diameter, wrong thickness. I took it over a couple nights ago to see if I could get it to fit. When I pulled out the old HR I found someone installed it backwards! OOPS! The new HR fit more or less and and I got 114w on my laser power meter. Not terrible, I guess. A new HR is about $300.

    I have been put in touch with a company that works with Lumonics lasers and I am going to have then redo the coatings on the rod soon now that I know this beast works.

    Leave a comment:


  • macona
    replied
    Last thursday I cleaned the optics and got the resonator lasing. I dont think the internal power meter is quite working right. I couldn't get the shutter to open, eventually figured out I need the doors closed on the cabinet to do that. Friday night I managed to set a paper towel on fire. Good progress.

    I brought the push wheel switches home last night to repair them. They have a little plastic arm inside that acts as a spring to return the buttons after they have been pressed. Over the last couple decades these cracked and are no longer spring like. I stuck a soft piece of rubber in its place and that seems to work fine.

    I took them back over today and reinstalled them. They work pretty good now. While I was there I decided to install the cutting head back on the Z slide. When I did this I found it was grossly out of line with the center line of beam. I spent the next hour realigning everything. It looks like this was the way it was when it came from the machine builders.

    Got everything tuned in pretty well. I just cant get it to stabilize to a stop. The motors just dither, real annoying. I am getting pretty close to ditching this software and moving to LinuxCNC.

    For fun I decided to see what it could do, I put a coke can in there and brought it into focus and fired away, here is the damage, not bad for old flash lamps and hammered cavity optics:


    IMG_2258 by macona, on Flickr

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  • macona
    replied
    I took some distilled water over and filled it up. Hit the power button and ran into two problems. Leaky filter seal and the shaft seal on the pump leaks. It's a Lowara PB40/A pump that looks like was only sold in the UK. I think I found the shaft seal, only available in the UK, £60.90. Ouch...

    Also found one of the transformer cooling fans is dead, no big deal on that one, there is a spare for it.

    It does not leak too badly so I hit the power button for the power supply. I hear a click and nothing else happens. I start looking at the schematics and see I should have 48v for the main contactor and there is nothing. A bunch of tracing and I find a loose fuse holder on the power distribution board. They used an extra thick PCB and the leads on the fuse holders are not really long enough and the joint broke. I managed to shock the living hell out of myself finding this out. I am going to be sore in the morning.

    Now I have 48v to the time delay relay on the DC Panel (Blue knob in above pic). The relay is not activating, it is just a snap on module on top of a more normal contactor. I disconnected it and popped it open, looked OK and then I noticed the plunger was stuck. I pulled on it a little bit and it popped loose and began to work normally. It had just sat too long and the rubber glued itself together. I proceeded to put it back together and hit the power button. The lights in the building flickered and the ready light came on. I hit the local button and the flash lamps started firing. I have not checked for emission yet.

    A little video of it doing it's thing. The panel controls for pulse width and rate are not too happy. Might have to replace those as well.

    Now I need to clean the collimator and the bend mirror and see if I have anything.

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