Tonebars and deflection

[french guy]

Hello all
I'm about fitting my tonebars , and the way I use for mount
my mandos permit to work that way .
Look at the pics attached .
The back is Not mounted , but neck , sides and top are all togheter.
Here is the project I want to test as John Garrity have done
there 1 or 2 years ago.
I put two calipers on the bridge and give tension until
pitch is OK, then I let the system during 2 /3 days ( stability) , then take the pitch again , and when it's good , I work on the tonebars , with the gouge until the calipers react .
( I try to write short because my modem is not OK )
I think I will see a first deflection , during the tension of the strings and this deflection will come from the edge of the top .
I think I will go over thez real pitch ( maybe # for exemple
G/G# D/D# A/A# E/E# , just to have a safety margin .
I must say also that the actual action is higher than the reality.
The second deflection will be given when I pull wood from my tonebars .
I'm very interested by your differents opinions

[french guy]

one pic closer

[french guy]

And the back

It will be dificult to work on tonebars that way , but I MUST
try.
Now I let you , I go back to my mando , put the tension .
If , tomorrow morning my mando is explosed , I keep you informed .

[ShaneJ]

Very interesting idea, Jean. Keep us posted on the results.

[sunburst]

I can't help asking; How does it sound?
You must have at least plucked the strings while it was in the jig.

[french guy]

Ok , yesterday evening I've try to put tension and all
go right until the tailpiece explode , I was extremely
stressed during 2 seconds , but no damage to the mando .
I think I must consider seriously the 160 lbs tension
of the strings .
however , I've heard the sound product and I wonder
if the back is really necessary http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif
I can say that I have made an "open-back mando" http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif
maybe a good instrument for old time ( LOL )
Seriously , I have seen the first deflection during I gave tension to the strings . I've start with the couple D strings , then with the A strings , the calipers react ,
then the couple G strings , and when I tuned the E strings
the test was immediatly stopped . I'll build a stronger
tailpiece next evening , and test again .

[Skip Kelley]

Cool idea! Keep us posted Jean.

[french guy]

hello all
I'm about update my webpage and it take a while
follow the link below to have infos about what I'have doing
this last WE.
http://perso.wanadoo.fr/jl-mand....rs.html (http://perso.wanadoo.fr/jl-mando/construction/tonebars/us_tonebars.html)

this page is not linked with the rest of my site yet.
but I'm pressed to give you infos
I'm trying now to find a system to give the FFT window
as window popup in my webpage , and not find yet .
I try to explain and explore this idea .
Let me know what is your opinions

[John Bertotti]

Everyones ears and tastes are different. I actually like the tone of the before G strings better all the rest The after sounds fine. I wonder what the assembled instrument will sound like with the same test notes? I also wonder how changing where you thin the bars will affect the tone. like more deflection on the treble side and less on the bass or any variation of the theme. Cool test. Thanks for sharing. John http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif