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Thread: Wood Screw Alignment?

  1. #1
    Tin Can's Avatar
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    Wood Screw Alignment?

    Last night I removed 20 tiny screws from a old Japanese studio camera

    Very heavy duty ART, wonderfull woodwork and fabulous fittings

    ALL flathead only, with all slots aligned perfectly

    Most interesting all had the same torque!


    How do they do that?


    I am very familiar with modern Torque to Angle stretch bolts
    Tin Can

  2. #2

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    Re: Wood Screw Alighment?

    Quote Originally Posted by Tin Can View Post

    How do they do that?

    Very carefully


    Glad to help…

  3. #3

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    Re: Wood Screw Alighment?

    I remember taking apart a Leica IIIF...backing out the small machine screws underneath the inner bottom works-cover. Those screws did not wiggle one bit for the entire length of their travel! I'd later heard that Leitz would often, with the aid of a very fine grinding compound...lap-fit those screws so they'd fit perfectly! Metals were compatible so no issues with variable expansion/contraction coefficients, which would help allow for this precision.

    Very cool though - in the case of wood screw slots orienting consistently with the same torque!

  4. #4

    Re: Wood Screw Alighment?

    Here's a youtube video of Christopher Schwarz explaining how to "clock" screws.

    https://www.youtube.com/watch?v=n8pplD3sd-Y

  5. #5

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    Re: Wood Screw Alignment?

    A friend does hi-end classic car restoration, and most of his customers have a fixation to have ALL engine bolts perfectly aligned in a row... It requires that the shoulder of all the bolts have to be machined perfectly so they all match, but put them back in in the wrong order and watch the owners squawk!!! :0

    Steve K

  6. #6
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    Re: Wood Screw Alignment?

    Bad idea

    Most modern head bolts are stretch to angle

    I am positive I have installed more than any other human

    Factories install all bolts at once to angle

    I would never bow to a rich fool that may ruin an engine



    Quote Originally Posted by LabRat View Post
    A friend does hi-end classic car restoration, and most of his customers have a fixation to have ALL engine bolts perfectly aligned in a row... It requires that the shoulder of all the bolts have to be machined perfectly so they all match, but put them back in in the wrong order and watch the owners squawk!!! :0

    Steve K
    Tin Can

  7. #7

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    Re: Wood Screw Alignment?

    Ha! Sounds analogous to a guy I knew, who, after having applied sheathing to his DIY house-build, then applied his house-wrap, but did so with the "Tyvek" logo facing inwards, as he did not like the look of it facing outwards. Thing is...Tyvek (and Typar, etc.) is formulated to act as a breathable, one-way moisture barrier - and by running it backwards, any moisture exterior to it gets sucked inwards! So a double-fools errand...seeing as such a barrier is designed to be covered up by a final (clapboards, etc.) layer. Then again...when I built a house pretty much by myself back in the early 1990's - I was, by the time of having run my Tyvek, so exhausted and financially strapped that I'd wished that house wrap could be available simply printed with a "clapboard" design! Would need to replace this every few years...but its relatively cheap and goes up quick.

    As for those engine head nuts...yes, that is sacred ground. For my 944, its torque to 15lbs...then go back and tighten each nut in a specific pattern/sequence - first to 90 degrees (angular) then wait fifteen minutes, then another 90 degrees. This is especially true if the bolts have been replaced as that "waiting period" gives those bolts time to stretch, but I still follow this even if I re-use the old bolts - which is generally OK (if a first rebuild) for my car's overbuilt/underpowered engine, especially if it had been properly maintained, nor had never been overly stressed or abused (tracked or raced in the case of a 944). Otherwise, the "bi metal" arrangement of steel bolts in an aluminum/silicon ("Alusil") engine block can indeed create some headaches (as it does, more frequently, on the earlier air-cooled 911 engines, which are subject to a bit more heat).

  8. #8
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    Re: Wood Screw Alignment?

    Ford and Roush

    Spec all TTA as one usage, we recycled all

    Lots of bolts!

    We also had our internal machine shop grind top and bottom all bolts to a special surface finish, flatness, RA and exactly parallel top and bottom

    Next thermocouples inside the gasket, with lead shot in holes

    We also used expensive motion sensors in small holes

    Then we use a single spindle TTA power wrench too heavy to hand hold

    and way more

    I used to fly to Detroit and San Antonio with all the gear on a purchased seat
    I was there for Gulf War 1 to supervise Mil spec our products
    They all failed and shipped anyway
    Tin Can

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