Violin Forum/Message Board

[okawbow]

I have a cello that I made about 6 years ago. The saddle has broken loose 2 times now. The last time, the ebony it'self split.

Am I doing something wrong? Or, is this a common problem. I made a new saddle, and made it wider and slightly lower this time. Will it hold, or do I need to go wider still?

http://www.flickr.com/photos/20524843@N03/4760329233/

[Janito]

The saddle is too high and the shape is wrong. As a result the tailgut is a strong tendency to pull it forward.

[okawbow]

The saddle in the picture is 5.5mm high above the top. Is that too high?

This cello has an 88mm tall bridge on a fairly high arch. The saddles that broke were a little higher. I'm worried about making the saddle too low, as the cello has a wonderful sound and ease of play.

[Janito]

My apologies, an optical illusion made it appear very high.

I still think the shape is not right. A correctly shaped saddle should sit in its slot with no glue because the tailgut force is directed with a vector that keeps it is place.

[rs]

The height of the saddle on a cello, according to Strobel, should be 12.5 mm from end block to top of ridge. I don't work cellos much, (if I can help it!) so I just looked up the measurement.

Two things that might help. One is the gut should be a tangent to the saddle. This means, it should not form an angle of any kind as it comes off the saddle but should simply exit the curve of the saddle in a straight line much as the pavement is a straight line, or tangent, exiting the curve of a tire. It will help to move the peak/ridge of the saddle closer to the tailpiece instead of the peak being in the center. This will means the maker should shape the curve towards the tailpiece such that the gut/line exits like a string wrapped around a pipe and not from the center of the saddle.

The second thing is the end pin looks too far extended. If it is set a bit deeper to where the bead is almost in contact with the rib, it will approach the saddle more erect. This means the line/gut will come in contact with the saddle lower, that is, closer to the ribs, and not higher. It is the LOWER contact, not higher that keeps the saddle in place, because the lower contact prevents the saddle from rocking over. Also the more the contact area, line to saddle, the more the force is distributed. Both of the above ideas will greatly improve this area of contact.

One other thing, the line looks a little long, but it would need to be measured from tailpiece stop (the ridge on the tailpice to contact the strings) to bridge. Strobel gives this distance to be 120 mm.

Janito is right, the saddle should function without glue.

Hope this helps.
_________________
Randall Shenefelt

[okawbow]

Thanks Paco,

It may not look like it in the picture; but the gut contacts the saddle evenly from the peak to the bottom. I think the other saddles were too high, and had less contact area with the end block. This one looks like it would stay in place without glue. I may try setting the end pin in more later, but I don't have a reamer for that. I had to fit it in place with a file and chalk.

I measured the distance from the bridge to the tailpiece stop, and it is slightly more than 120mm. I tried the set up at first with the tailpiece all the way back, but it played better with the gut a little longer.

[rs]

I still would try advancing that edge a bit towards the tailpiece. If it is off-center, it gives alot more curved surface for the line to rest in, it rests better, and doesn't want to rock. That's just what I think.

As for the measurement, I understand what you are saying on that one. There are a few things I do simply because I know others will be weighting what they see with what they expect to see. Some of them are crucial, some not, but people think they are. A few measurements I try to keep at all costs because intrinsically they matter; nut to top, nut to bridge, tailpiece to bridge and that sort of thing, on violins anyway. The bridge to tailpiece is the least important in that group, I suppose. You gotta go with your own feeling on that, and with the results that you are after.

That is a pretty varnish on the cello.

All the best. Hope this helped
_________________
Randall Shenefelt

[Jack H.]

Is it FLAT where it is glued tot he bluck? does it fit perfectly at the edge of the top? the curved part that the tail gut goes over should be about 2/3 of the width. might need more curve. do you glue it down with a clamp?