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Thread: IMSAI 8080 Paddle replacement results thread

  1. #1
    Join Date
    Dec 2011
    Dallas, TX

    Default IMSAI 8080 Paddle replacement results thread

    My IMSAI 8080 recently sustained some damage (another thread) and luckily survived with only some broken switch paddles. Unfortunately, the paddles are no longer available in the orignal color, aside from NOS or used paddles at exorbitant prices.

    The red paddles are NKK Part# AT4157C and are available and stocked.

    There are white paddles, NKK PN# AT4157B, in stock as well. But mouser only had the light blue paddles, NKK PN# AT4157G, and I didn't check octopart for the white ones. Mouser also has better pricing.

    I figured I'd try dying the paddles and start a thread to record the results.

    I ordered some Rit Dyemore plastic dyes. There were not many colors to choose from, so I got:

    - Denim Blue,
    - Royal Purple,
    - Super Pink,

    I tried a few recipes. For reproducibility, I added dyes in increments of 5mL (1 tsp). The closest recipe so far is:

    32 oz (1 qt, 960 mL) cold water, brought to a boil and reduce to a simmer, just below boiling in a 2 qt pot
    10 mL Denim Blue
    15 mL Royal Purple

    I placed the light blue switch paddles in a small strainer, and swirled them in the hot water, completely immersed, for 20 seconds. Then I removed them and dunked them in a clear cold water bath, and dried them. This is the result:
    Photo Aug 02, 8 08 25 PM.jpg
    From left to right, 1) New light blue switch, 2) Dyed switches, 3) Original IMSAI switch.

    The original switch has a slightly brighter blue color, closer to cornflower blue, and the dyed switches are a tad too navy, but adding much more purple (or pink) seems to be too purple. To replace one switch, you'd have to replace them all, but still the dyed switches are not too bad a look on the IMSAI, and are better than the light blue option.

    I have some white keys on order and will see if starting with a white switch gets closer.

    Has anyone else tried dying the switch paddles? Any suggestions? I suppose it would be possible to dye a set of paddles with each dye for a standard amount of time (20 sec), then photograph them, sample the colors to RGB, then do a singular value decomposition to try to match the color as close as Rit can get.


  2. #2


    How many switches and what colors do you need?

  3. #3
    Join Date
    Jan 2010
    Central VA


    You might try vinyl dye, too. That comes in a bunch of colors. Used to be the product of choice for making beige boxes less beige I bought mine at the local auto parts store, apparently its intended purpose was coloring vinyl interiors in cars.


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