Neck Pull-down

[Brad H]

I have never tried one of these and would appreciate any comments from those who have.  I have the top off on a violin whose projection is 2mm on the high side.  Here is what I am contemplating.  

-  Remove 0.5mm(?) from the back side of the table neck cut out.

- Glue the table in its normal position from the bottom block up to, but not including, the upper blocks on each side

- After the glue has dried, apply a force on the neck/FB to lower the projection and glue the rest of the seams and the upper block. (here is where I wish I had one of those upper block gluing clamps to ensure good contact between table and block).

Any comments or suggestions?

 

[duane88]

Take off the fingerboard and plane the neck down to lower the projection. I've never been a fan of pulling the neck down.

Either a little off the neck and a little off the board, or a reverse wedge would be my suggestion.

[~ Ben Conover]

What projection do you have now and what are you aiming for.
if the neck thickness and over stand allow it, you could just plane a little off the neck. 


 

[Brad H]

Yeah, I don't have enough wood to plane the neck to lower the projection.  And I have already done all I can with the FB.  Current projection is 29mm.

13 minutes ago, duane88 said:

I've never been a fan of pulling the neck down.

Are you concerned that the pull-down won't stay down?

[Jerry Pasewicz]

7 minutes ago, Brad H said:

Yeah, I don't have enough wood to plane the neck to lower the projection.  And I have already done all I can with the FB.  Current projection is 29mm.

Are you concerned that the pull-down won't stay down?

What is the overstand, where is the violin from, and how old is it?

 

 

[~ Ben Conover]

New violin ? It might come down 1.5 in a year. 

[Brad H]

It is a German factory 1920's(?) violin.  The overstand is just under 5mm from table edge.

[~ Ben Conover]

Well, you could proceed as you intended perhaps use closing clamps to hold the lower bouts in place, so that you can glue the top on in one go, or get it right if it doesn't work first time.....since your guestimate of 0.5mm off the table neck mortice may not be exact. 

if the table is in good condition at the neck root then you may not need a special under the f/b clamp anyway....you could also use a wedge under the f/b I spose. 
Your call. 

[Jerry Pasewicz]

9 minutes ago, Brad H said:

It is a German factory 1920's(?) violin.  The overstand is just under 5mm from table edge.

Sorry to hear that.  I have never liked, or have done, neck pull downs.  Maybe someone else has expertise with these.

[Brad H]

 

13 minutes ago, ~ Ben Conover said:

Well, you could proceed as you intended perhaps use closing clamps to hold the lower bouts in place, so that you can glue the top on in one go, or get it right if it doesn't work first time.....since your guestimate of 0.5mm off the table neck mortice may not be exact. 

Good suggestion.  I'll start with maybe 0.25mm and see what that gets me.

Thanks for all comments.

[David Burgess]

1 hour ago, Brad H said:

I have never tried one of these and would appreciate any comments from those who have.  I have the top off on a violin whose projection is 2mm on the high side.  Here is what I am contemplating.  

-  Remove 0.5mm(?) from the back side of the table neck cut out.

- Glue the table in its normal position from the bottom block up to, but not including, the upper blocks on each side

- After the glue has dried, apply a force on the neck/FB to lower the projection and glue the rest of the seams and the upper block. (here is where I wish I had one of those upper block gluing clamps to ensure good contact between table and block).

Any comments or suggestions?

 

There are lots of options for either raising or lowering the "neck projection". Without having the violin in my hands and considering all the variables, I couldn't say which would be best.

[chungviolins]

If the arch is high, then neck reset is the best option.

5mm overstand is too low if the arch height is 15 or so.

[chungviolins]

I do reverse, pulling neck up.

Pulling down doesn't work like pulling up.

[Marty Kasprzyk]

Make a new bridge 2 mm higher.

[nathan slobodkin]

I have done this kind of pull down and aside from the difficulty of cutting back the top with the violin assembled (not an issue in this case) I have never seen any problems with it. I  would try to do your final gluing of the top with strings tuned to tension while measuring  neck pitch as would also be done with a neck being pulled up. However if there are other problems such as an apuis that is too low you might just bite the bullet and reset the neck.

[Brad H]

Thanks for all the input. 

1 hour ago, nathan slobodkin said:

aside from the difficulty of cutting back the top with the violin assembled

Yeah, that does sound difficult.

 

1 hour ago, nathan slobodkin said:

I  would try to do your final gluing of the top with strings tuned to tension while measuring  neck pitch as would also be done with a neck being pulled up.

I can see the benefit of doing this on the pull down.  But, for the pull up, it would seem to make the task of getting the shim in place more difficult.

[nathan slobodkin]

Brad ,

Specially made sideways dogleg chisel can get under the finger board. Still a real pain but doable.

The shim goes in first before the instrument is strung up then glue applied, instrument tuned to tension and clamps applied. If this is not done the neck will tend to drop again over time. Rene's method. I'm surprised Jerry did not encounter neck pull downs at Rene's I know I did several. 

 

[Jerry Pasewicz]

1 hour ago, nathan slobodkin said:

Brad ,

Specially made sideways dogleg chisel can get under the finger board. Still a real pain but doable.

The shim goes in first before the instrument is strung up then glue applied, instrument tuned to tension and clamps applied. If this is not done the neck will tend to drop again over time. Rene's method. I'm surprised Jerry did not encounter neck pull downs at Rene's I know I did several. 

 

I may have mis-stated, when I have done them it was only a matter of removing the previous shim.  As a matter of fact, we use ebony for projection raises so the removal is easier, cleaner, and there is no doubt where the shim ends and the top begins when the neck is finally re-set.

In the same vein, button clavettes are oriented so medullary rays match the back and not the neck for the same reason.

[Brad H]

I did the pull-down, the violin is strung up again, and the FB projection is now 28 mm.   At this point,  I can not perceive any problems with the procedure.

[nathan slobodkin]

1 hour ago, Brad H said:

I did the pull-down, the violin is strung up again, and the FB projection is now 28 mm.   At this point,  I can not perceive any problems with the procedure.

Cool!

[baroquecello]

A very silly question. What is the Problem with a somewhat high projection? A low projection makes bowing difficult, and sometimes is detrimental to the Sound, but a high projection shouldn't cause the Player Problems, should it. Does the increased pressure on the belly cause structural damage on the Long run, or does it choke the Sound? Why wouldn't one just leave it as it is and hope for a 2 mm drop over the Course of the coming centuries?

[nathan slobodkin]

Definitely bad for sound . Maybe too much downward tension maybe because of overly high bridge but usually an overly tight thin obnoxious sound.