Results 1 to 12 of 12

Thread: Armrests? magnets?

  1. #1
    Registered User belbein's Avatar
    Join Date
    Oct 2011
    Location
    Atlanta, GA
    Posts
    2,255
    Blog Entries
    3

    Default Armrests? magnets?

    I've been thinking about arm rests. What has got me sweating is the problem of securing them. One of the instruments I want to put an arm rest on is my Octave, which of course is too thick for most of the readily available brackets. The brackets themselves give me no confidence, and people are always complaining about the arm rests coming off, unless you really tighten them down, and then you have the problem of damage.

    So I'm thinking to myself ... what about rare earth magnets? A ridge along the outside bottom edge of the armrest would align with the edge of the top and keep the arm rest from moving toward the center of the top, and the magnets should keep the whole shebangs from shifting. There might be some compression, but probably no more than with those darn brackets. And maybe there'd be some change in sound, since all sound is electromagnetic anyway?

    Comments?
    belbein

    The bad news is that what doesn't kill us makes us stronger. The good news is that what kills us makes it no longer our problem

  2. #2
    Member
    Join Date
    Jan 2007
    Location
    Boulder, CO & Chesterfield, MO
    Posts
    2,564

    Default Re: Armrests? magnets?

    1st, I've never had a problem with my armrests coming off. They do leave a mark when you remove them, if they've been on for a while. However, playing without one also causes wear.
    I don't think you'd get magnets strong enough to resist movement, and you'd get probably worse wear with that.
    What about an adhesive, guitar-type arm rest if your OM is too big to take the barrel type armrest?

  3. The following members say thank you to colorado_al for this post:


  4. #3
    Registered User Charles E.'s Avatar
    Join Date
    Feb 2007
    Location
    Saint Augustine Beach FL
    Posts
    4,924

    Default Re: Armrests? magnets?

    Interesting idea. It would be easy enough to do a mock up with scrap wood to test it.
    Charley

    A bunch of stuff with four strings

  5. #4
    Moderator MikeEdgerton's Avatar
    Join Date
    Mar 2007
    Location
    40.1646 N, 74.2083 W
    Posts
    24,123

    Default Re: Armrests? magnets?

    If you know anyone that works in an older data center with older Compaq servers the broken SCSI drives yield huge curved rare earth magnets that might destroy some wood but they would hold. I've used them to clamp braces on repairs.
    "Bargain instruments are no bargains if you can't play them". These are the words of J. Garber.

  6. #5
    Registered User Charles Kelley's Avatar
    Join Date
    Nov 2011
    Location
    Gainesville, GA
    Posts
    10

    Default Re: Armrests? magnets?

    Quote Originally Posted by belbein View Post
    And maybe there'd be some change in sound, since all sound is electromagnetic anyway?
    Unless you are playing an electric instrument, your instrument is producing pressure waves in the air, not electromagnetic waves. If you use a pick up in the instrument or a mic in front of it you'd have possible issues with the magnetism in the rare earth magnet. But I do not believe it would be because of the magnetism.

  7. #6

    Default Re: Armrests? magnets?

    You could do magnets.
    I attach a bracket to the mandolin side with screws normal ("perpendicular") to the surface of the sides. Then I use really tiny #2-56 screws to screw up through the bracket into the armrest. Ends up looking like this:
    Click image for larger version. 

Name:	MG_0062-1024x682.jpg 
Views:	92 
Size:	98.0 KB 
ID:	175779Click image for larger version. 

Name:	armrest_2.JPG 
Views:	72 
Size:	71.4 KB 
ID:	175780Click image for larger version. 

Name:	armrest_3.JPG 
Views:	61 
Size:	129.3 KB 
ID:	175781
    Yes, you have two screw holes.
    But the normal chinrest style brackets aren't free from marring instruments, either. In fact, I think this mars the instrument a little on the top and a little on the side, while the normal chinrest clamps mar the top, side (several places especially if you're sloppy with the adjuster thingy) and the back as well.
    Pretty much guaranteed to be able to tell an armrest was mounted, whichever way you slice it.

    But to answer your question, you could use rare earth magnets. These armrests I make barely even need to be screwed on. A couple 1/4" x 1/8" rare earth magnets would work just fine. Do it! I would put it on the side, not on the top, to avoid damping the top.

  8. The Following 3 Users Say Thank You to Marty Jacobson For This Useful Post:


  9. #7
    Member
    Join Date
    Jan 2007
    Location
    Boulder, CO & Chesterfield, MO
    Posts
    2,564

    Default Re: Armrests? magnets?

    Quote Originally Posted by Marty Jacobson View Post
    Click image for larger version. 

Name:	MG_0062-1024x682.jpg 
Views:	92 
Size:	98.0 KB 
ID:	175779
    Wow! That is gorgeous!
    What a cool armrest bracket too!

  10. The Following 2 Users Say Thank You to colorado_al For This Useful Post:


  11. #8
    Registered User
    Join Date
    Feb 2011
    Location
    Conneaut Lake, PA
    Posts
    4,075

    Default Re: Armrests? magnets?

    Have you ever looked at the Weber allin one tailpiece and arm rest assembly? I think it’s a really good idea, but I bought one once and found, at least for me, it was poorly executed. I thought the wooden armrest part of it was flimsy and bendy. I think if someone took that design and made the armrest part of it beefier, they would have something. Of course, then you have the problem of screw holes possibly not lining up in the case of retrofitting. Such a thing would probably be best installed during original construction.
    Don

    2016 Weber Custom Bitterroot F
    2011 Weber Bitterroot A
    1974 Martin Style A
    Fender Octave Mandolin c.2004-2008

  12. #9
    Certified! Bernie Daniel's Avatar
    Join Date
    Oct 2006
    Location
    Cincinnati, Ohio, USA
    Posts
    8,283
    Blog Entries
    4

    Default Re: Armrests? magnets?

    Interesting thread and ideas. Marty's magnetic thing looks nice!

    However, in my opinion there is nothing wrong with the "traditional" clamp-on option.

    I have used and made clamp on arm rests for the entire mandolin family including octave mandolins and mandocellos. You can buy the longer hardware you just have to look for it.

    And if you use cork padding on both contact surfaces (also felt will work but it's not as "grippy") you can easily tighten the arm rest securely and still not produce any damage to the instrument. I've fixed up at least 50 or more instruments and never had any unsolvable issues with it falling off or doing damage?

    Yes I imagine damage could happen if care is not taken e.g., over tightening or with some very soft finishes? But I've never had a problem myself with the violin (viola or cello) chin rest clamps?

    Another option is just to permanently attach the arm rest with silicon cement. I've done this with a couple of mandolins that I've made and it makes a clean looking arm rest that stays in place, and finally it does not seem to damage the finish (lacquer and tru-oil in my two trials). And yes, I realize that wet silicon cement has acetic acid but this seems to evaporate long before any finish damage occurs?).
    Bernie
    ____
    Due to current budgetary restrictions the light at the end of the tunnel has been turned off -- sorry about the inconvenience.

  13. #10
    but that's just me Bertram Henze's Avatar
    Join Date
    Jun 2005
    Location
    0.8 mpc from NGC224, upstairs
    Posts
    9,944

    Default Re: Armrests? magnets?

    I never needed an armrest on my OM and, in fact, thought they'd be needed on the slim body of the mandolin only - up to now, that is.
    Standing corrected
    the world is better off without bad ideas, good ideas are better off without the world

  14. #11
    Bridger Products
    Join Date
    Feb 2003
    Location
    Bozeman, MT
    Posts
    132

    Default Re: Armrests? magnets?

    Bruce Weber, Montana Lutherie, and I prototyped a new tailpiece/armrest concept (similiar to my Weber design but I think better) for his new instruments last Saturday that uses magnets to allow access to the string posts. It worked well and he may have a model to sell in the near future.

    As to Don's observation on the Weber tailpiece armrest. The early ones that I built were quite stiff (enough wood over the tailpiece section) but I can't speak for the later products...

    Vern Brekke
    Bridger Products

  15. #12
    Registered User
    Join Date
    Mar 2003
    Location
    Columbus, GA
    Posts
    1,283

    Default Re: Armrests? magnets?

    Spencer Oliver in Marietta can help you. He made an arm rest for my octave and it's as good as any I've ever seen. It's custom-sized for the mandolin. He's a member here: "Soliver"
    David Hopkins

    2001 Gibson F-5L
    Breedlove Legacy FF; Breedlove Quartz FF
    Gibson F-4, (1916); Blevins Octave Mandolin, 2018
    McCormick Oval Sound Hole "Reinhardt"
    McCormick Solid Body F-Style Electric; Slingerland Songster Guitar (c. 1939)

    The older I get, the less tolerant I am of political correctness, incompetence and stupidity.

Posting Permissions

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