Page 1 of 3 123 LastLast
Results 1 to 10 of 28

Thread: Flex mounts - solid base fixing?

  1. #1
    Join Date
    Feb 2008
    Location
    East Sussex, England
    Posts
    5,244

    Default Flex mounts - solid base fixing?

    Ok, so I've got a lot of flex mounts, some of Dave's and some of Rob's, and all of them exhibit a tendancy to move on the baseplate when adjusting.
    No matter how hard I bolt them down (whilst ensuring no threads are stripped!), I still sometimes get an involuntary 'letting go' as I try and tweak one of the axis, resulting in the beam being way off. the ones from Rob seem to be a bit worse as they have a 45 degree cut at the back, which leaves less metal to metal contact between the baseplate and foot.

    So, is there a tried and tested way to fix these down better? Once they're in place, they don't really need to move, so I'm thinking epoxy, maybe solder of some sort to hold them fast and solid. Am I the only one who experiences this?
    Frikkin Lasers
    http://www.frikkinlasers.co.uk

    You are using Bonetti's defense against me, ah?

    I thought it fitting, considering the rocky terrain.

  2. #2
    Join Date
    Dec 2006
    Location
    Essex, UK
    Posts
    8,647

    Default

    do what the Chinese do, glue! ;-)
    Eat Sleep Lase Repeat

  3. #3
    Join Date
    Feb 2008
    Location
    East Sussex, England
    Posts
    5,244

    Default

    Any suggestions? Hot melt ain't going to do it, epoxy of most sorts has a habit of not keying properly and cracking off. Cyano perhaps?
    Frikkin Lasers
    http://www.frikkinlasers.co.uk

    You are using Bonetti's defense against me, ah?

    I thought it fitting, considering the rocky terrain.

  4. #4
    Join Date
    Dec 2006
    Location
    Essex, UK
    Posts
    8,647

    Default

    there is an engineering solution but it took me ages to work it out and I don't want to give away my design.

    maplin do a good two part epoxy, I really like it
    Eat Sleep Lase Repeat

  5. #5
    Join Date
    Feb 2008
    Location
    East Sussex, England
    Posts
    5,244

    Default

    Maybe flexmounts need a slightly longer foot/slot, so you can get a pair of screws in there. I've thought about drilling small holes each side into the baseplate and inserting pegs to lock it up solid.

    Given that you've thought up a solution, it is apparent that its not just me who's encountered it, which is heartening.

    Is that a long set epoxy, or a 'rapid'? I find the 2hr+ ones work much better.
    Frikkin Lasers
    http://www.frikkinlasers.co.uk

    You are using Bonetti's defense against me, ah?

    I thought it fitting, considering the rocky terrain.

  6. #6
    Join Date
    Dec 2006
    Location
    Essex, UK
    Posts
    8,647

    Default

    when you have two very smooth machined surfaces sat on each other they are going to slide

    theres a far easier solution but its in the design of the mount, not the surface it sits on.

    they do a range from like 30 seconds to a few hours I believe
    Eat Sleep Lase Repeat

  7. #7
    Join Date
    Dec 2008
    Location
    veenwouden
    Posts
    2,558

    Default

    My suggestion would be do a re-design, manufacture 100 pieces and do a groupbuy. That way you help others aswell. There must be a metalshop arround the corner.Maybe even Andy can do the metalwork for you so its a win-win-win situation for you , andy and the rest of PL that are joining the gropubuy. Problem solved


    Interested in 6-12W RGB projectors with low divergence? Contact me by PM!

  8. #8
    Join Date
    Dec 2006
    Location
    Essex, UK
    Posts
    8,647

    Default

    I don't need to do a group buy I have enough mounts for what I need and I have my own design.

    im more than willing to help others out, but when you spend a lot of time and effort perfecting a design why give it away?
    Eat Sleep Lase Repeat

  9. #9
    Join Date
    Dec 2008
    Location
    veenwouden
    Posts
    2,558

    Default

    My suggestion would be do a re-design, manufacture 100 pieces and do a groupbuy. That way you help others aswell. There must be a metalshop arround the corner.Maybe even Andy can do the metalwork for you so its a win-win-win situation for you , andy and the rest of PL that are joining the gropubuy. Problem solved
    Did i write Andy-con should give up his design and do a groupbuy?

    Northy can/should a re-design and you can mill it. He wants to solve his problem and with a groupbuy he also can help others. You make some money, he is doing the groupbuy and solve his problem aswell.

    Relax man, grab a beer!!!
    Last edited by edison; 10-10-2014 at 06:05.


    Interested in 6-12W RGB projectors with low divergence? Contact me by PM!

  10. #10
    Join Date
    Dec 2010
    Location
    DC/VA metro area, USA
    Posts
    554

    Default

    Norty, I haven't played with this mounts, but just thinking out loud... have you tried roughening up the mating surfaces to prevent slippage? A really rough sandpaper is a good start. Adhesives need places to bind; polished surfaces reduce their bond strength. You might could get away with working on just the mount itself if you cut some sharp grooves in the bottom, say with a dremel. This would give the mount some bite to resist torque during adjustment. Imagine if the bottom of the mount looked like a file... I don't think it would go anywhere. If you could drill a hole in a hardened steel file (masonry, carbide, or cobalt bit), you could just put a piece of file between the mount and the baseplate, but that would mess up your height a bit.

    Also, are you using a washer between the screw and the mount? A flat washer will reduce the torque applied to the mount and lessen its tendency to turn during tightening. A star washer under the flat will fix really reluctant cases, but may be overkill in most situations.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •