Thanks Thanks:  0
Likes Likes:  7
Needs Pictures Needs Pictures:  0
Picture(s) thanks Picture(s) thanks:  0
Page 1 of 2 12 LastLast
Results 1 to 15 of 24
  1. 31st January 2014, 02:48 PM #1
    sinjin
    sinjin is offline Senior Member
    Join Date
    Jan 2004
    Location
    Melbourne
    Posts
    466

    Default Maximum timber thickness

    Simple but tricky question. If i had a plank of timber 12mm thick and just by chance it had a 1mm bow right in the center.
    Board length doesn't matter...say 1000mm for argument sake.
    I need to plane the board dead flat and also dead parallel what would be the maximum thickness i could get the plank
    when it is finished. This is a theoretical answer not from a practical point of view. Would the board end up being
    11mm thick or 10mm thick.
    Sinjin
    Reply With Quote Reply With Quote
  2. 31st January 2014 02:48 PM # ADS
    Google Adsense Advertisement
    Join Date
    Always
    Location
    Advertising world
    Posts
    Many





     
  3. 31st January 2014, 02:51 PM #2
    AlexS's Avatar
    AlexS
    AlexS is offline Dehydrated Hydrographer
    Join Date
    Jun 1999
    Location
    Westleigh, Sydney
    Age
    77
    Posts
    9,549

    Default

    In theory, 11 mm, but in practice, something less.
    Visit my website
    Website
    Facebook
    Reply With Quote Reply With Quote
  4. 31st January 2014, 02:57 PM #3
    Wongo's Avatar
    Wongo
    Wongo is offline GOLD MEMBER
    Join Date
    Nov 2003
    Location
    Sydney
    Age
    53
    Posts
    8,879

    Default

    a bit over 10mm
    Visit my website at www.myFineWoodWork.com
    Reply With Quote Reply With Quote
  5. 31st January 2014, 03:03 PM #4
    Chris Parks
    Chris Parks is offline GOLD MEMBER
    Join Date
    Jun 2005
    Location
    Helensburgh
    Posts
    7,696

    Default

    If I planed it, about 5mm!!
    CHRIS
    Reply With Quote Reply With Quote
  6. 31st January 2014, 03:56 PM #5
    sinjin
    sinjin is offline Senior Member
    Join Date
    Jan 2004
    Location
    Melbourne
    Posts
    466

    Default

    Hmm so far 1 right and 1 wrong..
    Reply With Quote Reply With Quote
  7. 31st January 2014, 04:20 PM #6
    justi227
    justi227 is offline Intermediate Member
    Join Date
    Nov 2012
    Location
    Lennox Head
    Posts
    39

    Default

    Maximum would be 10 as u need to take the 1mm of bow off both sides.
    Reply With Quote Reply With Quote
  8. 31st January 2014, 04:22 PM #7
    Wongo's Avatar
    Wongo
    Wongo is offline GOLD MEMBER
    Join Date
    Nov 2003
    Location
    Sydney
    Age
    53
    Posts
    8,879

    Default

    Quote Originally Posted by sinjin View Post
    Hmm so far 1 right and 1 wrong..
    17mm?
    Visit my website at www.myFineWoodWork.com
    Reply With Quote Reply With Quote
  9. 31st January 2014, 04:33 PM #8
    Wongo's Avatar
    Wongo
    Wongo is offline GOLD MEMBER
    Join Date
    Nov 2003
    Location
    Sydney
    Age
    53
    Posts
    8,879

    Default

    bow.JPG
    Visit my website at www.myFineWoodWork.com
    Reply With Quote Reply With Quote
  10. 31st January 2014, 04:39 PM #9
    elanjacobs
    elanjacobs is offline Taking a break
    Join Date
    Aug 2008
    Location
    Melbourne
    Age
    34
    Posts
    6,127

    Default

    In theory you lose the height of the bow, so you would have an 11mm finished size.

    Take 1mm off the ends of one face to make it flat on one surface. It is now 11mm at the ends and 12mm in the middle. Then take 1mm off the middle of the other face while leaving the ends and it's now 11 at the ends and 11 in the middle.

    As an interesting semi-linked note, if you halve the length of the piece, the bow is divided by 4, not 2 as one might think. Sounds weird, but the maths works.
    Reply With Quote Reply With Quote
  11. 31st January 2014, 04:48 PM #10
    malb's Avatar
    malb
    malb is offline GOLD MEMBER
    Join Date
    Oct 2007
    Location
    Alexandra Vic
    Age
    69
    Posts
    2,810

    Default

    Assuming machining.

    Jointing the concave side first to get 1 side straight and flat would reduce the ends to 11mm, centre of the bow would be untouched so remain at 12mm.

    Then thickness original convex side referenced to what had been the concave side. This would machine high spots at centre and barely touch the low spots at the ends, so slightly under 11mm would be theoretically achievable, 10.5mm might be practical by the time you take a light cut at the bits untouched on either side.

    For hand planing, probably reverse the sequence but similar answers, but you might have better cut control and practically achieve around 10.8mm.


    My 2c.
    I used to be an engineer, I'm not an engineer any more, but on the really good days I can remember when I was.
    Reply With Quote Reply With Quote
  12. 31st January 2014, 05:26 PM #11
    sinjin
    sinjin is offline Senior Member
    Join Date
    Jan 2004
    Location
    Melbourne
    Posts
    466

    Default

    Well done Alex...
    Reply With Quote Reply With Quote
  13. 31st January 2014, 06:24 PM #12
    Rod Gilbert
    Rod Gilbert is offline GOLD MEMBER
    Join Date
    Aug 2012
    Location
    Imbil
    Posts
    1,167

    Default

    I don't know what happened to my post it was there #2 for a while now it's gone ???
    Regards Rod.
    Reply With Quote Reply With Quote
  14. 31st January 2014, 07:35 PM #13
    malb's Avatar
    malb
    malb is offline GOLD MEMBER
    Join Date
    Oct 2007
    Location
    Alexandra Vic
    Age
    69
    Posts
    2,810

    Default

    Rod, the same question was posed with a slightly different title under wood turning forum. Maybe you replied there. I found that thread before this one and also though my reply had gone AWOL. Mind you haven't been back to confirm if yours is there.


    EDIT It is.
    I used to be an engineer, I'm not an engineer any more, but on the really good days I can remember when I was.
    Reply With Quote Reply With Quote
  15. 3rd February 2014, 07:32 PM #14
    sinjin
    sinjin is offline Senior Member
    Join Date
    Jan 2004
    Location
    Melbourne
    Posts
    466

    Default

    yes your right i originally posted on woodturners and tried to shift it to just general..anyway the answer is 11mm.
    Reply With Quote Reply With Quote
  16. 3rd February 2014, 09:03 PM #15
    Master Splinter's Avatar
    Master Splinter
    Master Splinter is offline SENIOR MEMBER
    Join Date
    Dec 2005
    Location
    Canberra
    Posts
    3,260

    Default

    I just don't theoretically purchase theoretically bowed theoretical timber...does that count as an answer?
    Reply With Quote Reply With Quote
Page 1 of 2 12 LastLast
« Previous Thread | Next Thread »

Similar Threads

  1. Maximum thickness
    By sinjin in forum WOODTURNING - GENERAL
    Replies: 51
    Last Post: 7th February 2014, 12:09 PM
  2. Maximum timber span length for pergola
    By Dengue in forum WOODWORK - GENERAL
    Replies: 2
    Last Post: 27th November 2011, 11:13 AM
  3. AS1684 - maximum undersize tolerances for timber used in structural applications
    By doodle in forum TIMBER
    Replies: 1
    Last Post: 27th February 2008, 05:05 AM
  4. Help with timber thickness
    By sbnx in forum TIMBER
    Replies: 1
    Last Post: 22nd September 2007, 08:50 PM
  5. Maximum veneer thickness
    By JB in forum TIMBER
    Replies: 2
    Last Post: 8th August 2006, 02:06 PM

Tags for this Thread

Posting Permissions

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

Forum Rules