Marimba!

  1. Screwdriver

    Screwdriver pre-moderated

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    Ok, so it's a xylophone really but marimba(!) is such a nice word, that's what I am gonna call it. Not too much time for this because I am making a Chrissie prezzie but since I have to pop into the house to Sketchup the process, I'll fire off some updates.

    Kept these old window frames for years because they look like mahogany (could be cedar??).

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    This was the cut I was worried about but it went really well. This wood is lovely to cut. No real grain to speak of.

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    I need to make these bars:

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    ...and working in fractional inches is a nightmare so I did a quick table in Excel.

    Have to work with what you've got so this is what I have, minus all the holes.

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    Sketchup helps with the cut selection. Sneak preview of the marimba included

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    And I have just enough material to work with.

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    Righty ho. Back to the shed....
     
    Parm, mrsbruce, Hopefuldave and 6 others like this.
  2. Domdom Forum Supporter

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    That’s fantastic. I do rather envy those with such capabilities.
     
    ukracer likes this.
  3. Screwdriver

    Screwdriver pre-moderated

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    Reality bites!

    Found some inconveniently placed holes in my stock. Also discover I had two 25" pieces I hadn't modelled. Update to account for holes and damage...

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    ...and just looking at the cut list now, I think I better start with that heavily populated 23" incher. Just in case it doesn't quite fit.
     
    slim_boy_fat likes this.
  4. Screwdriver

    Screwdriver pre-moderated

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    Never again! Inches and fractions should be consigned to the bin where they belong! I made an assumption (not checked yet) that the resonant frequency will be the precise value in fractional imperial notation so that 6 ¹³/16 is a more accurate way to hit a G note (because there's a line on the ruler) than say 173.0375. I now no longer care. I am going decimal and be damned.

    The plan was, tidy up one end square, mark it then mark the length and cut 1/16 long. The problem is, I had already been scribbling on these sticks and I am not used to fractional inch measurement. So I messed up the 9 ¾ which came up short, then started cuttting down the 9 5/8 before realising the one marked 9 5/8 was actually the 9 5/16 (which I had already cut to 9 3/8).

    :doh:

    Now try saying that out loud and making sense of it because this late in the day, I'm damned if I can!

    In my defense it's dark and I'm supposed to be getting ready for drinkies (I haven't had any eaties yet either).

    So I got this far and put it to bed until tomorrow.

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    What is quite magical though is how musical these bits of wood are already. It should come as no surprise given the target but even so, I fetched this old window frame out of a skip, cut it into bits and now suddenly it's playing tunes!
     
    julianthegypsy, Seadog, Parm and 2 others like this.
  5. Mark 2

    Mark 2 Forum Supporter

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    Is this a bass end sound or are these dimensions based on the mass of the wood?
     
  6. Screwdriver

    Screwdriver pre-moderated

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    The tone of a struck piece is dependant on the length of the wood. I think the support points needs to be a node of vibration and the ends are some precise figure like 23.5% of the length away from that or somesuch. I think the mathematical theory has to be balanced against practical experience so the numbers which "work" might not necessarily be the exact physics of the theory. I suspect that has something to do with the shape and thickness but it's the length which decides the tone.
     
    Parm likes this.
  7. Parm

    Parm Let The Games Commence

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    Look good but those strange numbers are making my head hurt
     
    selectedgrub likes this.
  8. Ali

    Ali Member

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    Looks really good, all the best presents are made at the 11th hour.

    That spreadsheet idea is fantastic, I don’t think its ever crossed my mind its possible to use fractions in a spreadsheet, shows what I know.

    Sincerely hope there is a video of you playing jingle bells on it to finish off the thread.
     
    barking mat and Screwdriver like this.
  9. Screwdriver

    Screwdriver pre-moderated

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    I thought they would be easy to work with but they are so similar I find it tricky to work out which is bigger, especially since I am cutting them 1/16 longer than the finished dimension. Or 1/8th I think.

    The immediate problem was using a verineer gauge to measure it for the best accuracy (obviates my comment about lines on a rule) but that doesn't do fractional inches.). 0.8127 you could guess is 13/16 (!) but not if you made the 8 13/16ths piece 1/8 longer than required, then just double check it with the vernier and find it has an even different number scribbled on it from a previous incarnation.

    I'll be using mm and be damned, probably put each on in it's own bag or pouch too because making it is easy, it's the logistics of keeping track of an item when you have to keep rubbing off the marked surfaces that's the problem.
     
    barking mat likes this.
  10. eLuSiVeMiTe

    eLuSiVeMiTe Member

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    Masking tape for marking and notes.
    Would have converted to mm before SketchUp let alone marking.
    Alright if you use it daily and grew up with it but it's alien to me.

    Nice project.
    One for my list
     
    Screwdriver, Gragson and Ali like this.
  11. Screwdriver

    Screwdriver pre-moderated

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    Once you've gone to the trouble of writing them down it's easy using the spreadsheet. First column is your "general" list, copy it to a second column and make that a "number" so it converts to decimal inches, then a third column x25.4. At that point I should have gone metric and given each bar a distinct name and not try to work out which one was the 9 7/8 or the 9 5/16, especially when the stock pieces are overlong anyway.

    It really did my head in and I am pretty sure I have one <unnameable> piece missing and two <unnameable> bars the same length. Grrr...

    Luckily, I started from the long end so if I made one too short, I could still use it to make a shorter piece. But that backfired on me when I didn't erase the previous marking! Confusing as hell. I need a lie down just thinking about it again.
     
    eLuSiVeMiTe likes this.
  12. ukracer Forum Supporter

    5653 5653 997885 668765653

    I wonder now many will recognise that string?

    What is much more spooky...as I just started typing in that it started playing on midnight mass..........stunning.

    The only other coincidence I had similar was someone at work asked for the TV to be turned over.....I complied and after I stepped back Physically tuning the TV upside down, the image was the right way up........the program was a wildlife program the animal was being filmed upside down.......very spooky.
     
  13. Screwdriver

    Screwdriver pre-moderated

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    I didn't but Google knows all. I might be boring and make this one up with the "correct" Orff notation (ABCD etc.) I was going to use letters and numbers to make this instrument into a game. I chose 13 bars (so I could have the whole alphabet in two rows) not realising it's a standard "Orff xylophone". TBH I'll be more than happy if I can get it done in time. Now I have seen a proper marimba, I really want to make one of those. Maybe just have it as a doorbell. :D
     
    ukracer likes this.
  14. Parm

    Parm Let The Games Commence

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    I bought a 10 quid vernier of eBay a while back. It displays fractional inches. Would have been perfect for this
     
    julianthegypsy likes this.
  15. Screwdriver

    Screwdriver pre-moderated

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    Sort of defeats the object I suppose. Only going fractional because I can match a line on a ruler. In reality, if I need 163.5125mm I probably shouldn't be chopping it up on a bandsaw!

    Pencil line and score with a kiridashi :D

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    Bandsaw makes a surprisingly good cut, though unsurprisingly this particular one is the worst of the lot!

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    Laid out on some rebar to test...



    There is a bum note I think and it might even be the one highlighted by god.

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    Some fun tuing now though I should think it will come down to a dodgy bit of wood. just need to work out which one is wrong.
     
    galooph and Morrisman like this.
  16. Parm

    Parm Let The Games Commence

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    Now the million dollar question, just why are you making this?
     
    barking mat likes this.
  17. Screwdriver

    Screwdriver pre-moderated

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    Christmas present... (for a friend who I am seeing in a couple of days - it's for her little boy).
     
    Parm, galooph and eLuSiVeMiTe like this.
  18. eLuSiVeMiTe

    eLuSiVeMiTe Member

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    Beaten to it by seconds.
     
  19. TechnicAl

    TechnicAl Member

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    Thats nice......but she will love you....bong, bong, bong....unless, of course, he can actually play it:laughing:
     
    slim_boy_fat likes this.
  20. Screwdriver

    Screwdriver pre-moderated

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    I think "too late" was going to be the retort anyway... :D
     
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