1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Electronics Finally finished my nex UV-box!!!

Discussion in 'Modding' started by Turbokeu, 8 Mar 2006.

  1. Turbokeu

    Turbokeu Minimodder

    Joined:
    30 Jul 2002
    Posts:
    347
    Likes Received:
    2
    This project started beginning of july 2004: Tracing a suited flatbed scanner (I bought three of them through eBay before I found the perfect one). This one is a Microtek, model Contest, for 15.50 Euro. It's my preferred model because it has a descending front panel allowing me to mount the display/keyboard PCB:

    [​IMG]

    The search for a Philips tanning device (I bought 1 through eBay, 3 through a local store):

    [​IMG]
    [​IMG]
    [​IMG]

    Dismounting of the unneeded parts on the inside of the scanner:

    [​IMG]

    A little measuring to see if it fits:

    [​IMG]

    The original PSU of the scanner:

    [​IMG]

    New PCB based on the original power inlet and switch:

    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]

    In the meanwhile I cut/filed/drilled/bent new aluminum profiles to support the original lamp/starter sockets of the Philips tanning device:

    [​IMG]
    Again, checking if everything fits:

    [​IMG]

    The position of the lamps has to be a bit adjusted:

    [​IMG]

    The original connections on the back side have been covered with a sheet of anodized aluminum:

    [​IMG]

    (To be continued)

    CD :)
     
  2. Turbokeu

    Turbokeu Minimodder

    Joined:
    30 Jul 2002
    Posts:
    347
    Likes Received:
    2
    Finally finished my nex UV-box!!! (part 2)

    March 2006: Finally I had the courage to finalize my new UV-box. The cabling is now finished, PIC-PSU, PIC16F84-timer and display/keyboard are mounted:

    [​IMG]
    [​IMG]

    Inside view of the cover with the display/keyboard PCB. The original glass plate has been covered with (expensive) 3M-film to diffuse the UV-light:

    [​IMG]

    Inside views - unneeded parts of the chassis have been removed with a jigsaw:

    [​IMG]
    [​IMG]
    [​IMG]

    PIC16F84-timer with buzzer (on the left) and PSU (on the right):

    [​IMG]
    Mains entry connected:

    [​IMG]

    2x9V transformer for the PIC-timer:

    [​IMG]

    230VAC LED circuitry to feed the original green LED on the front:

    [​IMG]

    Display in minutes/seconds, status LED for the UV-lamps and one of the 3 push buttons:

    [​IMG]

    Before ;):

    [​IMG]

    After:

    [​IMG]

    I just now have to expose some test-PCB's to determine the correct exposure time.

    CD :)
     
  3. Hazer

    Hazer In time,you too will be relixalated

    Joined:
    14 Apr 2003
    Posts:
    957
    Likes Received:
    2
    Nice.
     
  4. SteveyG

    SteveyG Electromodder

    Joined:
    23 Nov 2002
    Posts:
    3,049
    Likes Received:
    8
    I remember those first pictures from all that time back when you first posted them!

    How come you've chosen to diffuse the glass like that? I've not seen an exposure box that has required the need for that, or are the tubes too close to the glass?
     
  5. Turbokeu

    Turbokeu Minimodder

    Joined:
    30 Jul 2002
    Posts:
    347
    Likes Received:
    2
    Do you? ;)

    My old UV-box has a 'milky' glass plate which works very well.
    As I had that 3M-film laying around (leftovers from the company logo on the windows of our office) I decided to use it.
    As a flatbed scanner is much more compact (height) than the old wooden UV-box the UV-tubes are also much closer to the glass plate.
    If it doesn't help it doesn't hurt either...

    I still have to make some test exposures to find out the correct exposure time and check the quality of the light diffusion over the whole glass plate.

    Anyway I keep my old UV-box for large PCB exposures (like my 4.0" LED display board).

    CD :)
     
  6. Hybr1d

    Hybr1d Bаnned

    Joined:
    13 Dec 2005
    Posts:
    883
    Likes Received:
    0
    Sweet, very creative :)
     
  7. Turbokeu

    Turbokeu Minimodder

    Joined:
    30 Jul 2002
    Posts:
    347
    Likes Received:
    2
    I had some time to proceed to some test exposures with my new UV-box.

    Above: Bungard sheet with which I never failed a PCB.
    Under: Velleman sheet with which I never succeeded to make a PCB... :duh:

    [​IMG]

    Close-ups of the Bungard sheet:

    [​IMG]

    [​IMG]

    Everything from 150 to 210sec and even 240sec of exposure is okay (60seconds of development in NaOH).


    Close-ups of the Velleman sheet:

    [​IMG]

    [​IMG]

    Everything from 150 to 180sec and even 210sec of exposure seems okay but there are remaining copper leftovers on the etched part (development was maybe too short - 90sec in NaOH - anyway I don't like this Velleman sheet, it's sh*t, I can't manage to obtain a perfect PCB...)

    CD :)
     
  8. ChriX

    ChriX ^

    Joined:
    30 Aug 2001
    Posts:
    2,651
    Likes Received:
    4
    Wow that is a really nice project, well done. :)
     
  9. Mafney

    Mafney What's a Dremel?

    Joined:
    23 Nov 2005
    Posts:
    85
    Likes Received:
    0
    Agreed, you have done some really nice work. Keep it going!! :thumb:

    Good luck with all your future projects as well.
     
  10. Macaba

    Macaba What's a Dremel?

    Joined:
    4 Mar 2006
    Posts:
    107
    Likes Received:
    1
  11. bigal

    bigal Fetch n Execute

    Joined:
    8 Oct 2004
    Posts:
    609
    Likes Received:
    0
    [topic jack]
    haha, when chris origionally started this like 2 years ago i stole his idea (and his PIC timer project ;) and whipped my own version up in a couple of weekends (needed one for a paid job)

    [Link to pics]

    ironically, the PCB i made up for the timer was one of the best PCBs i ever made, i still get probs if i try and do a too big PCB in this thing... I am planning a oven style one next, as i beleve they are more effective. (and you can use a vacuum to hold the transparency down, which is much more civilised.

    Also i replaced the whole glass im my scanner with sandblasted glass from a local glazer.

    Brilliant timer project BTW, thoroughly reccomend it!

    -Alex

    BTW: i am a cheap skate and allways use the economy rapid PCBs (probably why they come out so poor most of the time)

    [/topic jack]
    yours is infinatly more civilised and better made, mine looks like a monkey made it, which is not too far from the truth!
     
  12. mattthegamer463

    mattthegamer463 What's a Dremel?

    Joined:
    26 Nov 2004
    Posts:
    2,804
    Likes Received:
    1
    Um, im sort of confused. What does the UV light do to the PCB? I may build one of these if it proves useful to me.
     
  13. Turbokeu

    Turbokeu Minimodder

    Joined:
    30 Jul 2002
    Posts:
    347
    Likes Received:
    2
  14. Turbokeu

    Turbokeu Minimodder

    Joined:
    30 Jul 2002
    Posts:
    347
    Likes Received:
    2
    Hi Alex,

    The main thing is that it works!

    About the issue with bigger PCB's: put a blank sheet of white A4 paper on top of the glass, power the tubes and check uniformity of the UV-light through the whole surface of the sheet.
    If not, add a (or modify the) reflector under the tubes.
    I used the original preformed reflector from the Philips tanning device.
    Although it works I can see some small linear zones on the A4-sheet were the luminosity is a little less bright.
    It seems that the reflector is too directive in some areas.
    I will probably replace it by a blank sheet of 0.5mm thick aluminum.

    The quality of the photosensitive PCB sheet is indeed very important.
    The Bungard sheet has a very large tolerance in the exposure time, that's why I only use this one.
    As you can see in the above pics I have quite bad results with the Velleman sheet.
    (Bungard and Velleman are the two brands commonly found overhere).

    Also, do not skimp on the developer. I use those little KF 35gram bags to mix in one liter of warm tapwater.
    I tried using cheap NaOH pellets with very varying results.
    A well exposed PCB can easily be ruined by a bad development.

    On the following PCB the smallest clearance between tracks is 10mil, without problems!
    [​IMG]

    CD :)
     
  15. bigal

    bigal Fetch n Execute

    Joined:
    8 Oct 2004
    Posts:
    609
    Likes Received:
    0
    i am now using pure caustic soda for this, as a friend gave me a huge tub of it origionally bought from RS, seems to work ok...
    I think the problem is probably caused by the Eco type board from rapid, i should probably pay the extra few pence and get the non econamy version...

    My scanner version just has a sheet of tin foil as used to wrap food underneither the tubes as i couldent get enough distance from the glass with the origional reflelector. I do think a oven type enclosure with the tubes 8" - 1 foot away from the board..
     
  16. JCG

    JCG What's a Dremel?

    Joined:
    1 Dec 2005
    Posts:
    396
    Likes Received:
    0
    It looks nice , already saw it on GoT ;)
     
  17. Macaba

    Macaba What's a Dremel?

    Joined:
    4 Mar 2006
    Posts:
    107
    Likes Received:
    1
    Well you say that, but my college use the eco board, and they get beautiful results. They use a standard UV box, show in this:

    http://www.rapidelectronics.co.uk/r...CAT_CODE=30343&STK_PROD_CODE=M29467&XPAGENO=2

    The designs are printed on transparencies in a laser printer.

    The etchant used is:
    http://www.rapidelectronics.co.uk/r...&CTL_CAT_CODE=&STK_PROD_CODE=M29448&XPAGENO=2
    And the tank used is:
    http://www.rapidelectronics.co.uk/r...CAT_CODE=30343&STK_PROD_CODE=M29473&XPAGENO=2

    I'm not sure which developer is used. Perhaps you could try that clear etchant? It usually takes only 4-10 minutes to get a nicely done board.
     

Share This Page