stainless steel 8x11mm film cassette

Discussion in 'Minox' started by jimmy_li|1, Oct 8, 2013.

  1. Ready for the testing
  2. Wow. This looks like a remarkable piece of machining. How do you deal with the light traps though?
    It might me a good idea to paint the inside black to stop any light that does get in being reflected?
    It's great that someone is trying things like this.
  3. Indeed a very good looking experimental piece. Jimmy, I would take this a bit further and see if this metallic object (steel I guess) can be coated or annodized to make it all black. I would stay away of the magnetic powdering or surface painting: the first may (or may not, I am not a specialist)) interfere with the circuits of various cameras, the second may flake off and send the tiny flecks inside the film chamber or into the camera innards.

    Alternatively, I suspect sandblasting it would make it less shiny, and give it a matted appearance and thus, less prone to light reflection. The common issue with shiny / luminiscent material such as steel is that, even with light-traps in place (which can be a pain to attach here, btw), can reflect inside the capped roll, given the innumerable angles light can work its way in.
    Anyways, a very good and proper job. Let us know how you fare when it comes ot actually using it. Thank you for sharing!
  4. Great, unbreakable cassette finally
  5. Jimmy, you make this stainless steel cassette with traditional machinery or with stainless steel 3D printing ?
  6. I believe I can spot traces of milling on the bottom of the take up spool well. Also on the lid of the box.

    But then again, the markings could be of the final polishing. Anyways, I am waiting for someone to post a feedback on using these steel marvels:).
  7. Thanks for Anthony,Julian and Martin:)

    I made it by traditional machine.I guess 3D printer can't make the film entrance part well.
    I am still in the business trip and will find the time to polish it and test the film myself.
  8. Perhaps a rubber coating process, or a teflon-based polymer...somehow? The layer adherence would have to be quite durable and good, in the same time cheap enough for keeping the manufacturign costs to a decent level. I am thinking along the line of the regular teflon polymer used to coat the cooking pots and pans...without scratching the layer on purpose, it may confer the cassette a longer life.
    To sum up, coating would have to be:
    • corrosion resistance
    • good non-stick / non-scratch properties
    • barrier protection to resist aggressive chemicals.
    Plus that the manufacturer can (and probably will) service the cassettes when the coating is off or chipped, for a decent price. Anyways, I suspect the coating will be done in the film wells, not on the outsides of the cassette, for it would be pretty much useless. Plus that the in-out actions, the coating will be worn off much quicker than the insides, which may last longer.
    Jimmy, have you considered patenting this? Because if you did, you might be entering into a spot of trouble. Does anyone know what is the situation with the copyrights on "minox" 9.2 cassettes? Martin? Gerald?
  9. That looks awesome!
  10. I thought metal cassettes were harderto use in the newer cameras like the lx and tlx. Still amazing though
  11. I made a horrible black stain in the SS sink when I poured a developer containing K ferricyanide down the drain. Won't scrub off with pot scrubbers and is still there some years later. :-(
    Wonder if it would work if you meant it to stain black? Sods law says it won't!
  12. On reflection it was Jack Dong's ULC-3 and that had Pot thiocyanate. Sorry 'bout that.
  13. You have already done the difficult work. The easy part is the finish. Stainless is very easy to blacken and it is at the molecular level. There both commercial places and makers of coating kits that are easy to use at home. Since stainless has at least 14% chromium, the blackening "baths" convert the chrome in the stainless into sulfides and they are dark grey to a "light" black color. The luster depends on the surface finish before blackening. A light bead blasting with Aluminum Oxide will give you a satin dark grey/"light" black finish. The finish also reduces the galling that is typical with stainless should keep the spool moving freely. The normal thickness of these coatings is 0.00006 to 0.0001", (that's 1/10 of one thousandth inch) so any concerns about dimensional issues should be moot. Stainless firearms are routinely treated this way and require no fitting or grinding to reassemble after treatment.
    (I also made just a Minox cassette from stainless a couple of years ago to see if it was feasible to make these on my small CNC mill. I only made a block, solid version but it fit in all my Minox's. I found that 303 was the easiest to machine. I would think that this would be helpful in keeping the material in the slit area from work hardening. What material was this cassette made from?)
  14. Hi Win,
    i was using the steel 304.And I met some problem.
    Now I changed the matrerial to Chrome-Plated Brass.
  15. Here is the photos
  16. I bought one stainless steel Minox cassette with stainless steel box
    with one stainless steel Minox cassette for $100 usd from Jimmy Li many years ago
  17. bravo

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