how to calculate the width of the bridge for a odd sized viola and tailpiece lentgh?

[eliseveldt]

how do you determine the ideal size lf bridge and tailpiece? 

the bassbar is placed according to weishaars book. the upper bout and lowerbout divided by 7 and a line drawn between the points. but how much should the feet be outside the bass bar? 

 

for the tailpiece im wondering if there is a certain number for. the afterlenght i should account for or if the tailpiece should be a percentage of the body length. 

[Davide Sora]

What are the dimensions of the viola?

[eliseveldt]

20 minutes ago, Davide Sora said:

What are the dimensions of the viola?

26cm lower bout

22cm upperbout 

lob 44.4cm

distance between f holes 10.4cm

distance from top edge to f hole notches 24.4cm

 

[Davide Sora]

I don't have much experience with such large violas, but in any case, I wouldn't go beyond a width of 50 mm between the bridge feet, and with the bassbar no more than 1.5 mm inside the foot. Keep in mind that the division of the upper and lower bouts into 7 parts only serves to establish the inclination, not the position of the bassbar.

For new instruments, it is always best to determine the width of the bridge before gluing the bassbar, placing it relative to the width of the bridge, not vice versa. But since this is a baroque viola copied from the original Stainer, you may want to refer to the original bassbar position and the original bridge width, to get as close as possible to the original sound, if that's your goal.

[eliseveldt]

40 minutes ago, Davide Sora said:

I don't have much experience with such large violas, but in any case, I wouldn't go beyond a width of 50 mm between the bridge feet, and with the bassbar no more than 1.5 mm inside the foot. Keep in mind that the division of the upper and lower bouts into 7 parts only serves to establish the inclination, not the position of the bassbar.

For new instruments, it is always best to determine the width of the bridge before gluing the bassbar, placing it relative to the width of the bridge, not vice versa. But since this is a baroque viola copied from the original Stainer, you may want to refer to the original bassbar position and the original bridge width, to get as close as possible to the original sound, if that's your goal.

thankyou i didnt know the 7 division is only for the inclination. however if i redraw what i did the position of the bass bar falls in the ballpark of where it needs to be with a 50mm bridge. i will probaly stick to that size for now. for the original i couldnt find any plans or drawings so only had some photos and aproximate measurements. 

[The Violin Beautiful]

I’d consider a few things for the bridge size:

1) spacing of upper ff eyes

2) bass bar placement. I’d like the bridge to be 1-1.5 mm outside the bar ideally. I agree with Davide’s comment about bar inclination. 
3) fingerboard width. If the bridge is especially wide, you may end up with the strings closer to the fingerboard edges or you’ll have a string spacing in the bridge that leaves a lot of wood at either side. 
4) projection of the neck. If it’s lower, a wider bridge may end up looking a lot more stubby and you may not have much wood above the heart. Make sure the projection is adequate for the blank

5) c bout clearance. This is related to 5), and it’s also important to have enough clearance for the bow so that it’s not running into the bouts. 
 

As far as the tailpiece, I tend to gauge the size by the proportion to the vibrating string length, not the body length. I would choose a tailpiece that allows the right ratio and comes close to the saddle without touching. 

[MANFIO]

I agree with Davide too. I have no experience with tenors...  the viola jungle is a wild one. I am a viola maker and I use 52 mm bridges for all my viola models from 39 to 43 cm (15.3 to 17"), with an upper a eye distance from 50 to 54, and the bass bar very near the upper eye.

Is it a commission? Violas over 42 cms. are hard to sell, in my experience.

www.manfioviolas.com

 

[eliseveldt]

58 minutes ago, MANFIO said:

I agree with Davide too. I have no experience with tenors...  the viola jungle is a wild one. I am a viola maker and I use 52 mm bridges for all my viola models from 39 to 43 cm (15.3 to 17"), with an upper a eye distance from 50 to 54, and the bass bar very near the upper eye.

Is it a commission? Violas over 42 cms. are hard to sell, in my experience.

www.manfioviolas.com

 

distance between the eyes is 68mm 

maybe a 52mm bridge wouldnt be a bad idea. 

this build is just a curiosity project. a baroque violist suggested it but i dont have any comision for it. i personaly never played this size so went ahead with the project

[deans]

I cannot help with any calculations. But as someone who has owned and played a lot of large old violas, sometimes you just have to try a couple. Yes, a lot of work.  Also a lot of testing time, it takes a while to figure out how to get a good sound out of any unfamiliar viola, and then you're playing with a significant parameter. It can pay off though.

I think it's worth considering that this looks like a period instrument. Many old large violas have evidence of earlier bridges being considerably narrower, meaning that perhaps there was a preference at some time, and maybe you want to lean in this direction. I have old 18th century M-wald viola, roughly the same size as yours, that has markings from a bridge that wasn't much wider than a violin bridge. Now I'll have to go measure. 

This goes for old violins as well, sometimes you have to experiment. One of the setup parameters that's sometimes overlooked.

[MANFIO]

5 hours ago, eliseveldt said:

distance between the eyes is 68mm 

maybe a 52mm bridge wouldnt be a bad idea. 

this build is just a curiosity project. a baroque violist suggested it but i dont have any comision for it. i personaly never played this size so went ahead with the project

Ok, I just make violas. Violas under 39.6 (15.5)  and over 42 cm (16.5) only under commission. 

[Altgeiger]

5 hours ago, eliseveldt said:

this build is just a curiosity project. a baroque violist suggested it but i dont have any comision for it.

There are certainly players out there who would be interested in an instrument like this one. I think viola size is like women's hemlines, and we are entering a new cycle of interest in larger violas.

[M Alpert]

This is interesting! Well done for going for it, looks great!!

As for set-up, I would definitely recommend starting as close to "normal" as you can, despite the size.

@Davide Sora's recommendation about the bridge foot in relation to the bass bar is good. Measure where your bar stands and choose a bridge width which will go just 1-1.5mm over it, and put the post in a similar (normal) relation. 

As for tailpiece length, I recommend shooting for the standard after-length of about 1/6th of the vibrating string length. Generally "baroque" or gut string set-ups seem to work well with a very short or stiff tailgut. So make a tailpiece which will accommodate those measurements.

@The Violin Beautiful also had relevant points about neck projection and c-bout clearance. But I'm guessing those decisions have been made already? In any case, I think don't go too acute with your bridge "string break angle" (not too high a bridge) - rather shoot for a shallow curve on top of the bridge, if you're worried about bow clearance. Most likely this size if viola was used as a sort of bratsch anyway, meaning playing double- and triple-stops and chords. 

Please, someone correct me on that if there's other evidence. 

Once it's set up and played in a bit, you can consider if it needs other solutions in order to improve it.

Let us know!!