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  • shop edm

    Some of you may remember the gloat edm in general, well its here, and its a mixed bag!
    Its a sodick BF275, with the iV controls on it. As landed, all 1700kgs of it.



    Through the dwarf sized workshop door, 1/2" to spare at the sides and I had to remove some sheetmetal and the counterweight pulleys from the top for clearance.


    Computer unit is quite big too, the fans and resistor bank at the top of the cabinet had to come off, but no big isssue, and I noticed a damaged resistor when I was disassembling.


    Inside its quite sparsely laid out which should help with fault finding.

  • #2
    Main control system is a bit of a oddball, hope this bit works as its very bespoke.


    The machine itself is controlled by this oddity, which is a nec pc98 "pc". I put pc in quotes because its not an ibm compatible, instead its a japanese market only pc98 with proprietory chips and cbus card slots.


    Monitor has seen better days too but more of that shortly.

    Comment


    • #3
      First things after testing the transformer was to bring up the 100v side of things and see what worked out of the controls without the rest of the machine powered. I had originally planned to do this in my office on the desk so bought a japanese 100v travel adaptor rated at 1000w, but when measured it put out 60v so had to go in the bin, if your planning similar caveat emptor...
      So I wired it up to a builders 240v->110 site transformer, and on my 220v supply that gave 107v, which is inside the japanese 100v +-10% tolerance, at 2kw capability, that'll do.

      First thing first, the pc refused to power up at all, completely dead, and the monitor likewise.
      A inspection of the monitor revealed the neck tube had fractured, so it was basically junk at that point, having no spare replacement tube to hand. I bought a japanese pc98 to vga adapter and tried that, but when it arrived it was to use a pc98 monitor on a pc, with the wrong genders at both ends.
      So I turned to the pc98, on decasing it, it was obviously different to a pc, but a psu might have been adapted with the soft start jumpered on the atx style units, so I decased the psu proper and noticed some capacitors bulged and some other components burnt. I replaced these, and the blown soldered in place fusible links, and got a power led and working fan. I pushed disks in and it started to do things then stopped with a warning beep.

      So I took the plunge and cut the monitor cable off the pc98 monitor and soldered it onto a old rack mounted pc monitor, figuring it would have more scan rate capability to cope with the very low frequency of the pc98 rgb output. And it worked. To be greeted by a "system not found" error.
      Some research pointed at the ultra rare 3.5 low rpm floppy drives being at fault, so I swapped drive 2 for 1, on the premise that 2 would be less worn, and it started to boot, until :-


      Which for those not familiar with very old versions of dos is the kanji version of "disk error, abort retry or ignore", I hit retry and ignore and finally got to this, please forgive the lack of bezel, its not in place yet and will be sorted :-


      That is a error from the sodick control system, so I know I have at least one good working floppy drive, even if drive 2 is bad. Incidentally Ive also stripped and cleaned drive 2 with alcohol and card on the read heads, and now it appears to manage to boot the original diskettes with the same errors as the other unit, so potentially its now just a bad diskette.
      Another oddity with these machines, is the floppy diskette contents are unique to that machine with error parameters and other things which have to match up to the machine's eprom settings done at the factory, so you can't just trade someone for a copy to get one going. I've emailed sodick to price a replacement for my machine as the disk errors indicate a failing diskette.
      Also I'm in contact with a project that replaces floppy disks with usb sticks, so hopefully once I have the correct floppies I can make a image and remove the disks themselves, and just use usb sticks.

      And in one last stroke of luck, I have sourced another PC9801UV in Japan, and its currently on a boat on its way over to europe. So fingers crossed it will have at least one good drive in too.

      Will update when theres more progress.

      Comment


      • #4
        Not sure this is the sort of thing for here, but I'll post this update and if anyone wants more they can shout up.
        PC98 turned up from Japan, and its spent its life in a office, so is nice and clean, with good mechanical components etc. It booted and worked out the box too and arrived with a keyboard and a cbus scsi card. For now I've just used the floppy drives to freshen mine up, but I'll keep it all safe for spares as theyre ultra rare to find.
        I managed to find a manual for a later different machine here, which is close enough to give me a clue how to diagnose the main edm controls :-
        https://s3.amazonaws.com/Icarus/DOCU...anuals_871.pdf

        And armed with that, I started to commission the EDM proper. Some headscratching later, the bad transformer turned out to be the one which supplies 200vac->100/18/17vac service for some of the timers and chassis functions, its been on fire and has leaked shellac so its a easy spot once its outside the cabinet but was originally buried deep inside the core. I have a 2kva 200->100v transformer spare, and borrowed the one from the bridgeport and did some fudging to generate the 18 and 17vac rails as a temporary fix, but found another trans out of a earlier machine with 18/17 rails for $20 + ship and will keep the 100v trans in parallel thats in there now.
        Then that done, further fault finding revealed yet another blown transformer supplying just 200vac->100vac for the rail which runs the controls and nec pc98, and it had taken out a contact on the contacter too. So a workround was done (ran it off the 20c switched 100vac rail with a jumper as my 2kva transformer is more than capable of servicing the additional load), and then discovered that the 5v 20amp switchmode supply that runs the control chassis computer had ac but no output. So now waiting for a 5v 30amp psu to arrive from a cctv vendor.
        I've also got the cabinet chiller module to fire up and its functioning, so it still has refridgerant in which is a bonus.

        I will persist until its either so damaged it becomes completely uneconomic to fix (I worry given the 5v rail damage that the main chassis computer is fried) or it fires up. Whats really important from it is I'm learning a boatload about how these machines operate and are put together, and thats not something you find a lot of chances to get loose on normally. I've learned some things that will let the bridgeport get finished easier also.

        Comment


        • #5
          Small update bump and a request for knowledge if anyone can help I'm stuck on a very frustrating aspect.

          Update is, have fitted replacement transformers, and now computer boots fully. Main chassis controller now also boots after a repair to one of the switchmodes, and some issues sorted out on the UV driver card & also a replacement servopack for the X axis was needed.
          I have ran through the machine and table moves, I also have working wire feed, chiller, have hooked up the water and flushing side and fixed some leaks and thats working too. The UV axis moves but can't see the end contacts so have to fix that yet.

          My issue, I don't know how the connections for the discharge cables to the workhead from the machine are made. Everything was removed, some of it missing its terminals and no cable markings at all.
          Would anyone know how the cabling is supposed to connect, either physically or at a logical level?
          I assume all the power output side to both sides of the wire dies, but how does the PIKA circuitry connect (theres a contactor inside the machine marked PIKA but no idea how this connects since PIKA is supposed to be for a micro polishing module located in the tank which I dont have).
          Also there are two heavy wires back to the machine workhead cabinet, whereupon once inside it they are connected to four smaller wires each which pass through relays and cabinets into the control side of things. I assume these are for voltage feedback to the control. How do these heavy wires link up to the wire guides? across both or lower and table ground to measure outputs and look for collisions?

          I have a circuit diagram, but its for the wrong machine and differs in this area a lot.
          Does anyone perchance have a sodick they can look at to help me here? All the images and videos I can find have the detail obscured, because theyre covered by seals in use I assume.

          Now frustrated at the amount of repair work I have done to the insides, only to be tripped up by the most basic "how to actually connect it" stage.

          Comment


          • #6
            I wish I was knowledgeable enough to make even a slightly helpful comment on your project but alas, 'tain't so.

            I just wanted to say thanks for taking the time to post all the great info & pics! It's not likely a project I'll ever get involved in but I really enjoy following along, looking over your shoulder as you tackle the various head-scratching obstacles. What you need at this point is to hookup with an amenable retired Sodick U.K. service tech and take 'im out for a pint or 6.

            Keep the updates coming as I'm sure there are many others out there that enjoy what you're doing as much as I do.
            Milton

            "Accuracy is the sum total of your compensating mistakes."

            "The thing I hate about an argument is that it always interrupts a discussion." G. K. Chesterton

            Comment


            • #7
              Tell ya what, I'm blown to He!! and Gone, at your prowice working thru that mess of E~issues!
              All greek to me, as to the nitty gritty, once / if you have it all ship shape......
              .... I might then be of some help, unless yer allready a Wire Savy Ace and don't need it.
              ==========================
              My only suggestion at this point is to ask George to over-ride the edit block
              and rename your thread.
              Hundreds of non-participants lurk here 24/7s.... to say EDM means a sinker to 97% of anybody.

              Call it WIRE call it WIRE edm, call it something, anything, but Not just EDM.
              A dozen wizzards out there will blow right past your thread, and anyone of them
              would have jumped at the chance to help out!

              Example:
              Rescueing Willy, my Wire EDM exploration.
              Last edited by Old Hat; 12-08-2014, 12:01 AM.

              Comment


              • #8
                Watching this thread with great interest. I've just completed a rebuild of a 1984 Fanuc Tapecut Model M wire EDM in my home workshop, which is I think rather earlier than your Sodick. Many electronic and mechanical repairs later it now runs superbly, and is a very useful and versatile machine. Yesterday I was cutting a length of 1.5 MOD rack from stainless steel to match some gears I'd made earlier on it.

                Point of the reply is to encourage you ... The end result will be well worth the considerable effort required.

                I had the advantage that mine uses a Fanuc 6m control and although ancient by current standards at least there are spares around and information to be had

                Comment


                • #9
                  Thanks all.
                  Oldhat, you may be surprised at how close to the die sinkers this is inside. It shares a lot of circuitry and the same firmware. The wire machines has some additional circuits for UV as this is a four axis machine and wire control, and the power control & movement reversal that the EDM process does happens on the X & Y axis's rather than the Z on a sinker. I'm not a wire ace, I've never seen one run in person as it goes but I have a few jobs that I will use this for when it runs, and all the time new ways of making other tasks keep occuring to me. I have the cad/cam package spewing out sodick gcodes, but the codes it spews are not all understood by the older processor on this computer, so I have to look at which code's it doesnt understand and do something with the post processor, or edit them into the nearest equivalent on the machine using the string file editor built in. I'll confess I'm more trying to get it to run first than sort out the cam stage & for that I can just use manual cut and simple programs keyed in.

                  Andrew there is information, but that in itself is a special tale of woe. Sodick charge a registration fee to be a customer, and its in the thousands. I did approach the uk distributer (soditech), but once they found out I didn't have a support contract they told me to contact the french office then stopped answering email. I certainly wouldn't give them a recommendation if I ever get involved in a buying decision for one of my clients. That was for the bespoke boot disk and manual initially.

                  I have had much better response from a company in the USA called McWilliams EDM, which although I haven't spent a lot of money with them (so far I've bought a replacement boot diskette) have been helpful and have spares if I need them. Import taxes and transport make it difficult to buy things outside the EU though. I'm not sure the correct manual would go into the detail I need, since its missing in the above linked maintenance manual.

                  Last night I decided to cable it up best guess and try it out, Ive read somewhere that the PIKA circuit is used only during edgefind routines so I left the two wires I didnt understand unconnected so I could observe the contactor before connecting it up. And the result was voltage on the panel voltmeters but no current on the meter and to the wire. The PIKA contacter was engaged even in cut manual mode, and the machine couldn't detect a wire collision when I ran the wire into a test piece on mdi testing it, so I guess that the PIKA contactor deals with wire collision detection all round.
                  I have been speaking to someone who works in a edm shop today and he came up with a rough concept sketch, which has lead to the idea of just putting a oscillloscope onto the 10 leads and seeing what comes out.
                  Frustrating all the same that "clean the discharge cables contacts" is listed as a maintenance task, but can't even find a photo or diagram showing how they reconnect. But, it has forced me into understanding more of the machine fully, enough to now add a W axis or similar in future.

                  Comment


                  • #10
                    Originally posted by MrFluffy View Post
                    Thanks all.
                    Oldhat, you may be surprised at how close to the die sinkers this is inside. It shares a lot of circuitry and the same firmware. The wire machines has some additional circuits for UV as this is a four axis machine and wire control, and the power control & movement reversal that the EDM process does happens on the X & Y axis's rather than the Z on a sinker. I'm not a wire ace, I've never seen one run in person as it goes but I have a few jobs that I will use this for when it runs, and all the time new ways of making other tasks keep occuring to me. I have the cad/cam package spewing out sodick gcodes, but the codes it spews are not all understood by the older processor on this computer, so I have to look at which code's it doesnt understand and do something with the post processor, or edit them into the nearest equivalent on the machine using the string file editor built in. I'll confess I'm more trying to get it to run first than sort out the cam stage & for that I can just use manual cut and simple programs keyed in.

                    Andrew there is information, but that in itself is a special tale of woe. Sodick charge a registration fee to be a customer, and its in the thousands. I did approach the uk distributer (soditech), but once they found out I didn't have a support contract they told me to contact the french office then stopped answering email. I certainly wouldn't give them a recommendation if I ever get involved in a buying decision for one of my clients. That was for the bespoke boot disk and manual initially.

                    I have had much better response from a company in the USA called McWilliams EDM, which although I haven't spent a lot of money with them (so far I've bought a replacement boot diskette) have been helpful and have spares if I need them. Import taxes and transport make it difficult to buy things outside the EU though. I'm not sure the correct manual would go into the detail I need, since its missing in the above linked maintenance manual.

                    Last night I decided to cable it up best guess and try it out, Ive read somewhere that the PIKA circuit is used only during edgefind routines so I left the two wires I didnt understand unconnected so I could observe the contactor before connecting it up. And the result was voltage on the panel voltmeters but no current on the meter and to the wire. The PIKA contacter was engaged even in cut manual mode, and the machine couldn't detect a wire collision when I ran the wire into a test piece on mdi testing it, so I guess that the PIKA contactor deals with wire collision detection all round.
                    I have been speaking to someone who works in a edm shop today and he came up with a rough concept sketch, which has lead to the idea of just putting a oscillloscope onto the 10 leads and seeing what comes out.
                    Frustrating all the same that "clean the discharge cables contacts" is listed as a maintenance task, but can't even find a photo or diagram showing how they reconnect. But, it has forced me into understanding more of the machine fully, enough to now add a W axis or similar in future.
                    4 Axis!! Terrific!
                    Nothing fluffy about your brain power dude!
                    Should change your screen name to Mr, Tenacity!

                    Just read thru your post again. There were three guys around here we'd turn to
                    to sort out monkey pucky, like you are doing.
                    One passed away from age, another allegedly on purpose.
                    And the third is so intence and accentric, he's a puzzle.
                    I've lost track of him.

                    Need a guy like you around these parts.
                    ==============================
                    Where the he!! did you put that?
                    Just noticed thr dry-stone wall behind it.
                    I wanna shop like that ~~~ ALL STONE.
                    Last edited by Old Hat; 12-08-2014, 12:39 PM.

                    Comment


                    • #11
                      I'd guess that the 'discharge contacts' are tungsten carbide lumps, circular in my machine, that the wire runs over to put volts onto it.

                      I've not worked out how to upload pictures to this forum, or I'd pop up a picture of my arrangement. There is a contact above the upper wire guide, and and other one below the lower guide, and the wire wraps a few degrees round it to make contact. Eventually the wire cuts a groove in the contact, and I have to rotate the tungsten carbide contact a few degrees to give a new surface to rub on. In the Fanuc case, the power leads are co-axial, the centre core going to the contact mounting, and the screen going to the machine frame close to the guides. The wire guides and contacts are isolated from the frame by being mounted on ceramic plates.

                      Pictures and a bit of description here:

                      http://madmodder.net/index.php/topic,10085.0.html

                      Comment


                      • #12
                        This is the sodick, there are the two carbides on the upper and lower wire dies as you describe that you have to alter for contacts as part of maintenance, but the 3 cables from these run to isolator junction blocks on the side of the machine table. There's four possible places the lugs can be connected to, two which are to table ground, and two which are linked together. When I first started the table segments were completely isolated, but it was just really bad connections between the copper strip joining them and now they all read 0 ohms between segments, which makes it a lot simpler!
                        Theres two of these blocks on two different sides, so I guess one isolated setup for the upper connections, one for the lower.
                        If you look at this shot of the table, you can see the 3 power leads from the upper die, coming down into the tank where they were lying loose. I think these link up to the isolated portion of that connector block on the right hand side of the pic on the edge of the machine table. The lower leads seem to go to the other one just out of shot.


                        Coming from the machine cabinet there are 8 cables for the power out, each with two connections in the cable, outer shield, and inner core are seperate terminals. So thats 16 connections to sort out, and of course it was all lying round in the bottom of the machine on arrival and the cables are missing their labelling. I marked them up after tracing through from the cabinet end, but not sure how they link onto the junction blocks. IE which is grounded and which is passed to the guides.
                        You can see the lead bundle originating in the output side of the machine here with the PIKA contactor on the lower right of the upper unit. When its active it shorts out the two red connectors with a jumpered connection wired across the contacts.


                        This is the wiring guide I'm trying to follow, it shows five cables, but there is no markings on the stand showing that end, nor another page in my manual detailing that end any better. And all the wiring codes have changed.
                        I can work back from the connection points, but I need to know which wire ends up on which wire die to do this. Or work it out by trial and error. I think the failing is because I don't understand fully whats going on with the electronics at this point, in particular what that PIKA relay switches in.




                        Then, an additional cable takes a contact from one of the junction blocks up to a sensor arrangement in the machine itself, weirdly contra to what I would expect, its red terminal is screwed to table ground, and the black connection to the linked isolated terminal.
                        Final confusion, there is a fifth lead out the cabinet unconnected to power output from a contactor named PIKA. All I can find reference to this is its a electro polishing feature, but its engaged all the time Ive since found out by actual experimenting. THe more I explain this out loud, the more it sort of starts to fall in place, it just needs a nudge and a clear up with the oscilliscope I think.
                        Last edited by MrFluffy; 12-08-2014, 03:24 PM.

                        Comment


                        • #13
                          Just a thought, on my Diesinker EDM it is possible to reverse the potential on the electrode for use cutting certain materials, though it is usually left set one way. Are the terminals there so polarity can be reversed?

                          As I understand it polishing is achieved by imposing an hf signal onto the pulsed DC of the wire - could this be what your PIKA relay is doing?

                          When edge finding my machine has the power to the wire turned off from the generator, so I have always assumed it senses an earth on the wire but I've never confirmed this. Possibly your PIKA relay switches some detecting circuit on and the power off?

                          Have you scoured the globe for other users? When I rebuilt a dead Traub CNC lathe I managed to locate a factory that had several and was able to visit and pick their brains When the Traub help desk started getting a bit shy divulging information I found sending a bottle of Glenfiddich to the chap I'd been emailing resulted in much more informative replies Perhaps the Sodick people like the good things in life

                          Comment


                          • #14
                            Ive got a thread on cnc zone with 100 views and 0 replies, and I have hunted for a picture or youtube of a machine tank where its possible to see the junction blocks clearly to try and work out the connections from, the problem being that most models of that era had submersible tanks. On the submersible models the wire guide connections are inside protective covers or arranged differently.
                            The only connection info I can find is some very sage advise to mark all the connection points before disassembling however I'm in this position because I didn't take the machine apart and its got no markings. Normally I expect its a non issue, as you would mark the points on something like this during disassembly.

                            I think the sodick people's idea of the good life is selling service contracts

                            On reversal, could be. Its pulsed DC so it will have a polarity. Whats also struck me is every time the machine has been upset with something its thrown a system error of some type. Now it just thinks its cutting away blissfully unaware its not doing anything, which leads me to think I've created a short to ground or not grounded the table out correctly situation at the lead connections.

                            Ok on the HF imposition, that makes sense and is new information to me, perhaps its configured by a cutting condition setting or one of the flags, I'll see if I can get it to disengage by playing with parameters & try to work out how it would connect if so without creating a short between the wire die connections.

                            Time for shed, osciliscope, pencil and paper and brave the 6c in there as I stole the space allocated for the wood stove for siting the 200vac 3 phase autotransformer in. I need to get it working to warm the shop up stop the dielectric freezing

                            Oldhat, sorry for not responding to the stone comment earlier. My house and workshops are traditional stone & mud ex farm buildings a few hundred years old. We bought the house as a ramshackle tractor/animal shed for cheap with dirt floors and no services and I've converted it into a house over the past five years myself. Its a nice building, but its been a long heavy job to remodel.

                            Comment


                            • #15
                              My Fanuc has two modes of operation. In one you set the cutting speed in a screen setting and tweak for good results, but that mode is hardly used at all. The other mode is 'servo mode' (despite the other mode obviously also uses the servo!!!). In servo mode the work is advanced into the wire and the gap measured by (presumably) measuring the gap voltage and the control conditions adjusted to minimise actual contact. If it wasn't actually cutting as in your case, the work wouldn't move far at all.

                              I have a setting screen on which I can adjust voltage, current, on time, off time, and wire tension. All these exist as well in a series of tables that can be called up individually by a command in the program. Wire speed and water flushing are controlled manually and there is a 'feed rate override' from 0-100%. Tweaking the setting screen parameters makes a huge difference to the cutting rate, and I am only just now getting confidence in playing with them. Some have counter intuitive effects so if a cut is bouncing a bit from having shorts, turning the feed rate override DOWN increases the feed rate!

                              I've never had much luck asking for help on CNC zone

                              **Later edit**

                              Cannot the Mr Mullet you were corresponding with on CNC-Arena let you have photos of his power lead connections?
                              Last edited by awemawson; 12-08-2014, 05:34 PM.

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