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Hello, I've just arrived here !

Discussion in 'Introductions' started by AWEMawson, Aug 23, 2012.

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  1. AWEMawson

    AWEMawson

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    Aug 23, 2012
    Found the forum whilst serching for details of in circuit ic testers - thought you see an interesting bunch!

    Now retired, I've spent a lifetime supporting industrial process control computers, and I like to keep my hand in.

    My current 'project' is a 1984 Micon 850 CNC lathe controller, based on an 8085 micro but now dead. No circuits, no obvious clues, and I'm 'knife and forking' my way through it. Nine rack mounted circuit boards, mainly LS TTL, about 30 to the card. I have a vague idea of the fault area, split between two boards. So far I've managed to ring out one card manually and plot the circuit in Protel Explorer DXP (four days work and now cross-eyed!), and am starting on the second. Slight delay as I'm having to define some of the ics on it in Protel. (It doesn't know an MM5035 Octal 80 bit shift register, and suprisingly nor does it know an MM2102 1K static ram chip.

    Hey - anyone know anyone who worked at Micon in Basingstoke in the mid 1980's ?????
     
  2. davenn

    davenn Moderator

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    Sep 5, 2009
    greetings and welcome to the electronics point forums :)
    i have a wee few yrs to go till retirement this way ;)

    look forward to see you joining in the discussions

    Dave
     
  3. CocaCola

    CocaCola

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    Apr 7, 2012
    Welcome, one question I have to asked is it really worth the time and effort to fix these old CNC controls when you can refit the machine with new electronics very reasonably?

    I understand that sometimes it's about the challenge, and that is all good and fine, I'm just curious if that is the case or if there is some real need to mend vintage outdated CNC circuits?
     
  4. AWEMawson

    AWEMawson

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    Aug 23, 2012
    The control (Numericon 850 made by Micon) is by present day standards very limited. However my plan is to get it going, so that I can evaluate the servo amplifiers and other controls ( hydraulic tool turrent, ait operated chuck etc) under real conditions before I re-fit it with a PC based (probably MACH3). Having said that in practice the 850 is perfectly adequate for my needs despite being light years behind the Heidenhain on my CNC Mill and the Fanuc on my Wire EDM machine.
     
  5. CocaCola

    CocaCola

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    Apr 7, 2012
    You have a Wire EDM, now you perked my interest :) Do you do any freelance work, now that you are retired? I asked because I fully know what shop rates are on wire EDM... I used to have a 'cash' hookup that would do my limited stuff after hours or during down time but that connection fell apart and I have been searching for someone that can work with me on more reasonable rates for small or single parts, I know setup and tooling charges are the name of the game for any shop, but many times they just push the cost beyond what is economical for single or low number parts...

    BTW I don't need anything done right now, but that could change in an instant or it might not... But, I could provide a profile if you would like to give a quote, I have had the profile quoted by dozens of shops so 'shop' cost for the part is well documented on my end... It's a long cut out of 2.25" thick aluminum, a single pass is plenty good for my needs...
     
    Last edited: Aug 25, 2012
  6. AWEMawson

    AWEMawson

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    Aug 23, 2012
    Wire EDM

    Wire EDM: It's a typical Andrew project - a technology I've not previously been involved with but would like to explore - acquired semi working but incomplete and in severe need of tender loving care. I've gone through it with a fine toothed comb, sorting it's little quirks and doing the things that should have been done over the years where it was last used. I don't do work for others commercially for a couple of reasons. Firstly I just don't have the time, despite being retired my project 'to do' list seems to get longer not shorter. Secondly the idea of retirement was to not have the pressure of other peoples timescales, and do my own thing for once! Amusingly the previous owner has asked me to run jobs for him several times, but I've always declined for the reasons stated. I think in your case also the postage and time delay of crossing the Atlantic might be an isue!
     
  7. thebluepuppy

    thebluepuppy

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    Sep 7, 2012
    welcome im new too
     
  8. AWEMawson

    AWEMawson

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    Aug 23, 2012
    Well, loads of progress. I've spent the last 6 weeks mapping out the circuits of 6 of the 11 cards in this beast and producing circuit diagrams. This has allowed me to work out the memory mapping of the 8085 based controller, and with the help of my newly acquired HP 1651A logic analyser identify 6 faulty ics. Having changed them I now can input data to the controller and get sensible responses! Now need to put it back into the CNC lathe and see what happens.

    I'm rather nervous of putting the three phase onto the GEC Gem servo drives as they've been sat idle for several years. If it was single phase I'd run it up slowly on a Variac to give the capacitors a chance to re-form - but it's three phase - any suggestions?
     
  9. duke37

    duke37

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    Jan 9, 2011
    You could put a bulb in each phase to limit the current.
     
  10. AWEMawson

    AWEMawson

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    Aug 23, 2012
    OK I'm glad to say time to put this project to bed. I managed to get at the DC bus bars for the servo amps, and slowly bring the volts up on a current limited lab supply. The servo psu deliveres a nominal 150v DC at 100amps so not to be treated casually! I removed the servo amps while this was happening so no motion would occur, and after a few hours connected the three phase. No dramas thank goodness. The controller is now reconnected to the CNC lathe and controls what it should. I had a few issues with the controller subsystem that manages the hydraulic tool change turret (based on a 6502 micro !!!), but that's now sorted. only cosmetic stuff to do now (new polycarbonate window, and clean up the 28 year old paint job) and as I say it can be put to bed. An interesting learning excercise.
     
  11. AWEMawson

    AWEMawson

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    Aug 23, 2012
    For those interested, I finished this CNC lathe project finally last year, and for a bigger challenge found another one in a sorry state to try and fix up. Blog in the link that follows, you'll have to register to see the pictures but it's free and painless and an interesting place anyway!

    Deleted link

    Note from Moderator....
    post SOME ( we dont need all 500) pics in this forum ... please dont force people to have to register on another forum

    thanks
    Dave
     
    Last edited by a moderator: Aug 15, 2013
  12. AWEMawson

    AWEMawson

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    Aug 23, 2012
    Dave,

    At the last count there were 500 plus photographs in that link you deleted showing a sequence of repairs to the electronics units of this complex beast - not practical to duplicate them here.

    ... your loss I'm afraid ... never mind
     
  13. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    Jan 21, 2010
    Fairly pointless anyway. I followed the link and there were no images...

    So not much of a loss for me.
     
  14. AWEMawson

    AWEMawson

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    Aug 23, 2012
    Well that is because you didn't register. :perhaps you didn't read that sentence in the offending post ??? Like many forums to see the pictures you need to log in. I >think< that is what Dave was moaning about ?
     
  15. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,175
    2,690
    Jan 21, 2010
    If that was your first post, it likely would have been deleted as spam and gotten you banned.

    However, since you have a few posts under your belt, we're giving you the latitude to make this a useful thread.

    If your post was in response to someone's question about some part of the repair of a CNC machine, then it would have been fine. But you're soliciting people to go to another forum somewhere and requiring that they join up to see any of your images. Is that fair?
     
  16. davenn

    davenn Moderator

    13,249
    1,746
    Sep 5, 2009
    what part of .....

    please dont force people to have to register on another forum

    did you not understand ??

    thread closed
     
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