Page 1 of 2 12 LastLast
Results 1 to 10 of 13
  1. #1
    New Member
    Join Date
    Dec 2011
    Location
    South East Asia
    Posts
    1
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Mylar mirror for Simulator Cockpit

    Hello everyone!

    On a Cross Cockpit Collimanated Display System, what would happen to the Mylar Mirror if the vaccum is left un-operational for a long period of time say more than 1 Month, will it damage the Mirror?

    Also does anyone have some kind of document which specifies the storage and the optimal operational conditions for MYLAR, such as temperature and humidity ?


    Regards

  2. Likes carlee007 liked this post
  3. #2
    150+ Forum Groupie Atomic_Sheep's Avatar
    Join Date
    May 2010
    Location
    Melbourne, Australia
    Posts
    166
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Mylar mirror for Simulator Cockpit

    Pretty sure you're overthinking this whole thing. What happens to your shoes if you don't wear them for a month? They get dusty, that's about it. As long as you don't leave it in direct sunlight in the middle of a desert, it should be fine. Not 100% sure but the useful life of the kinds of coatings that mylar mirrors have is generally 20 years or so at which point they lose their reflectivity (not sure whether its due to oxidation or because the material itself starts to break up, ruining the smoothness of the surface... either way it's oxidation that causes the problems). In terms of optimal conditions, you can probably find the specs for mylar on the internet i.e. what the operation temeperature is for the material. Other than that, obviously when it's hotter, you'll need less vacuum pressure than when it's cold etc etc.

  4. Thanks Tesla3D, christianeme thanked for this post
    Likes carlee007 liked this post
  5. #3
    150+ Forum Groupie
    Join Date
    Apr 2010
    Location
    Auburn, WA
    Posts
    204
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Mylar mirror for Simulator Cockpit

    The mylar won't be damaged by being left in the relaxed state.

    I haven't noticed a significant difference in required vacuum between hot days and cold days, but then I haven't measured that directly. The main issue Gene and I have had with temperature is that the adhesive we used gets soft when it gets hot, letting the mylar move on the frame.
    Lessons learned:
    - Use the thinnest mylar you can get your hands on - it will require less vacuum to draw down, so will put less shear stress on the adhesive.
    - give yourself plenty of edge margin. We've got 3" all around, and it's barely adequate. The pull-away happened in one spot where the edge is 2-3/4".
    - Keep things cool. Hot adhesive is weak adhesive.

    If it does get dusty, be very careful when cleaning it. the aluminum coating scratches very easily. Draw it down just far enough to take out the slack, then use an air duster to blow off the loose dust. if it's still dusty, use plain water in a sprayer, soak up the runoff as it runs to the bottom of the mirror, then blow it dry. DON'T wipe it.

  6. Thanks Tesla3D, Efe Cem Elci thanked for this post
  7. #4
    300+ Forum Addict



    Join Date
    Feb 2007
    Location
    California, USA
    Posts
    406
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Mylar mirror for Simulator Cockpit

    Mylar itself is very tough stuff. Back in the day, mylar was used as a drafting film and for developing circuit board art work because of its durability and dimensional stability.

  8. #5
    150+ Forum Groupie Atomic_Sheep's Avatar
    Join Date
    May 2010
    Location
    Melbourne, Australia
    Posts
    166
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Mylar mirror for Simulator Cockpit

    If chip packets are anything to go by, should be strong enough to easily withstand wiping, not sure though as I haven't ever touched the stuff but the manufacturing process is the same as far as I know.

  9. #6
    150+ Forum Groupie
    Join Date
    Apr 2010
    Location
    Auburn, WA
    Posts
    204
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Mylar mirror for Simulator Cockpit

    A chip bag is probably about 2 mil or thicker. Unless you have a really strong vacuum and insanely strong adhesive, you'll need much thinner mylar. We're using 0.5 mil.

    While the mylar itself is tough, the aluminum coating that makes it reflective is VERY easily scratched. Even a soft cotton cloth will leave visible marks if you aren't very gentle. Moreso, if the mylar is drawn down to proper shape, it is very close to its yield stress. At this point, it doesn't take much force to put a permanent 'dent' in the mirror.

    Take my word for this; I speak from experience.

  10. Thanks Efe Cem Elci thanked for this post
  11. #7
    150+ Forum Groupie Atomic_Sheep's Avatar
    Join Date
    May 2010
    Location
    Melbourne, Australia
    Posts
    166
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Mylar mirror for Simulator Cockpit

    Point taken.

  12. #8
    300+ Forum Addict
    Join Date
    Apr 2008
    Location
    Graham, WA
    Posts
    323
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Mylar mirror for Simulator Cockpit

    If you sneeze at 1mil wrong, you'll mar it. Even a dampened paper towel can leave scratches in it. The one thing I've found that works well is a Swiffer dry duster. It doesn't mar the Mylar, but you need to be damn careful that the plastic handle never comes in contact with the Mylar because that WILL mar it.

    g.

  13. Thanks Tesla3D thanked for this post
  14. #9
    10+ Posting Member
    Join Date
    Jan 2012
    Location
    Canada
    Posts
    12
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Mylar mirror for Simulator Cockpit

    I just had a thought about how to keep the noise down; use the shop vac to drop the pressure down to where you want it, then switch to one double-acting cylinder or two single-acting cylinders hooked up to one or two high-torque motor(s)/linear actuator(s) to maintain the vacuum. If you use a large cylinder, you won't need a lot of speed, just torque.

  15. #10
    10+ Posting Member
    Join Date
    Jan 2012
    Location
    Canada
    Posts
    12
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Exclamation Re: Mylar mirror for Simulator Cockpit

    DOH! Why didn't it occur to me before? YOU DON'T NEED MYLAR! Alsa Corp. makes amazing chrome paints, Mirrachrome and Killerchrome. You could make a rough mirror form in sections, add an inch or so of plaster (or w/e), have a CNC rig mill each section down to the exact shape, then finish and paint the assembled sections.

    P1030219_L.jpg

    REALCHROME-VS-MIRRACHROME-lg.jpg


Page 1 of 2 12 LastLast

Tags for this Thread