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Topic: Innerds of Resonator Guitars |
Alan Brookes
From:
Brummy living in Southern California
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Posted 6 Jul 2007 5:15 pm |
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Does anyone know where I can find photographs of the interiors of resonator guitars ? I don't want to take a can opener to one !
Or, failing that, a diagram ?
(Yes, I know I can buy a construction diagram from Stewart-MacDonalds but I'm thinking there must be some photographs on the internet somewhere.) |
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Brad Bechtel
From:
San Francisco, CA
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Posted 6 Jul 2007 5:17 pm
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Do a search for "dobro cone" in Google Images and you'll come up with many examples. Other search terms such as "dobro blueprint" or "resonator guitar insides" work as well.
_________________
Brad’s Page of Steel
A web site devoted to acoustic & electric lap steel guitars |
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John Rosett
From:
Missoula, MT
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Posted 7 Jul 2007 3:00 am
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| They're not that hard to take apart and put back together. I recently got a cheap dobro at a pawn shop, and replaced the cone and spider. I'd never done it before, and it took about 15 minutes. Take off the strings, take off the coverplate, and lift out the spider/cone assembly. Just be sure to get the spider nice and square to the strings when you put it back together. |
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Rockne Riddlebarger
From:
Cincinnati, Ohio, USA
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Posted 7 Jul 2007 5:15 am
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| Hi Alan, There are good photos of the magical innards of resonator guitars in Tom Wheeler's book (remember those?) THE GUITAR BOOK page 40...Rockne |
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Billy Gilbert
From:
Texas, USA
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Posted 7 Jul 2007 12:26 pm
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Take a look at "Resophonic Outfitters" web page or Beard Guitars.  Billy |
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Greg Booth
From:
Anchorage, AK, USA
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Alan Brookes
From:
Brummy living in Southern California
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Posted 7 Jul 2007 6:25 pm
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| Greg Booth wrote: |
| Beard sells this 34"x44" full size blueprint for 10 bucks. |
Thanks Greg. I blew it up as much as I could, and it seems to confirm what I am trying to find out, that the cone rests on the back of the guitar without a circular wooden strut.
The reason I'm interested is that I'm about to build an 8-string lap steel with a resonator and a Hipshot Trilogy. I want to build it so that the Trilogy is attached to a solid body, as are the tuners, so that all the lengthwise tension of the strings is taken by solid wood, with a steel brace, and only vertical tension is taken on the cone. This is to avoid the phenomenon of cone drop, where changing the tension on the strings makes the cone sink into the bridge, putting the other strings out of tune. It's a phenomenon most noticable on the banjo.
I think I can overcome it on a lap steel, whereas a Trilogy on a regular-bodied Dobro, where the top has already been weakened by the enormous hole, has been shown by several previous attempts by others to prove an impossible problem to compensate for. |
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Howard Parker
From:
Maryland
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Posted 8 Jul 2007 6:13 am
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| Quote: |
| that the cone rests on the back of the guitar without a circular wooden strut. |
==>Not correct. On this design the cone is suspended in a "soundwell", which in addition to housing the cone is the main structural element.
Without the soundwell or posts or top bracing (like the Beard E) the top will cave, in no time at all....
You should probably spend the $10 and look at it up close.
hp
Full disclosure...I am the Beard business guy.
_________________
Howard Parker
03\' Carter D-10
70\'s Dekley D-10
52\' Fender Custom
Many guitars by Paul Beard
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Greg Booth
From:
Anchorage, AK, USA
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Posted 8 Jul 2007 8:42 am
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My impression, gained from changing tunings a lot, is that it is the cone flexing that causes the detuning, not the guitar. The feet of the spider rest on a raised rim of the cone which flexes. Even if you totally stiffen the system lengthwise I think you will still have detuning with the changes in string tension. Any thoughts, Howard?
_________________
Greg
Kathy Kallick Band
www.youtube.com/user/aksliderdobro |
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Howard Parker
From:
Maryland
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Posted 8 Jul 2007 9:31 am
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Hey Greg...Long time no see 
I think in theory you are correct. I would point out that the "flex" is bound to happen anytime you exert pressure with the steel bar...which is always.
I maintain that the changes are so small on a typical scale length that it requires virtually no compensation by the player. You figure that there is typically only 1/16 inch total flex built in to the top of the cone (spider bridge), that is 1/32 inch between the rim of the cone and the edge of the "shelf". That distance is by design and used by many luthiers, allowing for cone flex and eventual movement (over decades) of the top...
This is all fodder for us coneheads.....
Cheers,
hp
_________________
Howard Parker
03\' Carter D-10
70\'s Dekley D-10
52\' Fender Custom
Many guitars by Paul Beard
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Alan Brookes
From:
Brummy living in Southern California
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Posted 8 Jul 2007 11:55 am
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| Howard Parker wrote: |
| ...Without the soundwell or posts or top bracing (like the Beard E) the top will cave, in no time at all.... |
Thanks Howard. I shall be building a soundwell: in fact the soundwell will be the only part of the instrument that's not solid. I thought of using something similar to a banjo pot. I don't mind spending the $10, it's just that what I'm proposing to build is so different from a Dobro or National that I'm not sure that it would do me much good.
I have two Dobro-type resonators, one wood and one brass, and a National TriCord. I haven't taken them apart, but I've shone lights inside and held mirrors. There's not much you can see. |
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Alan Brookes
From:
Brummy living in Southern California
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Posted 8 Jul 2007 11:59 am
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| Howard Parker wrote: |
| ...I maintain that the changes are so small on a typical scale length that it requires virtually no compensation by the player. You figure that there is typically only 1/16 inch total flex built in to the top of the cone (spider bridge), that is 1/32 inch between the rim of the cone and the edge of the "shelf". That distance is by design and used by many luthiers, allowing for cone flex and eventual movement (over decades) of the top... |
This is what I've long thought. It gives me inspiration to continue. |
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Chuck Fisher
From:
Santa Cruz, California, USA * R.I.P.
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Posted 8 Jul 2007 8:53 pm
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| keep us updated on your experiments, please. |
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Alan Brookes
From:
Brummy living in Southern California
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Posted 8 Jul 2007 10:52 pm
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| Yes Chuck, I will. I made a cardboard mock-up this afternoon to check out how it will go together. I'm also working on a lap steel with palm levers, and I'm converting an 8-string Multi-Kord to regular pedals. |
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