I have trouble drawing an arrow on a picture
Definition of a leak
- Thread starter Gheorghe
- Start date
There's one in every crowd.
Hi John
As I said, I agree that increasing the spring tension to make a pad seal won't last as long as a good sealing pad with normal tension. I guess it's a matter of degree that would affect how temporary it is. How uneven was it before increasing spring tension, how much was the spring tension increased, how much does and how deep does the tone hole press against the pad, etc. How fast (or slow) the pad will start leaking depends on all of these things.
I also "seat" the closed pads in the same way. I imagine they would seal against light with even less tension on the springs, but the springs have to be set to a certain tension to seal, just like the fingers.
My reasoning for doing the same as you that pads harden over time. They start somewhat soft to reduce noise and to overcome their own slight uneveness. The more accurate the pad is initially, the better it will keep this accuracy when it slowly hardens and loses its ability to that incredibly small accomodation it needs to do.
I would say pads are instlaled to an accuracy of about 0.01mm or better, because if I put my 0.015mm feeler between a pad and tone hole then the leak light shows what I consider a "leak" that is more than I expect to overcome by a finger or a spring.
The pads that I have seen where spring tension was increased to overcome inaccuracy were mostly on new instruments where it was not possible to do anything about it for budget reasons. It is sometimes possible to reduce spring tension in these cases, but not as mcuh as would be optimal. Since the pads sealed with this spring tension and budget was very limited, it was preferred to leave it (and fix whatever was more critical on the instrument). In these cases, I have very rarely seen the problem shown in your drawing. Maybe it happens more when the the difference between pad inaccuracy and spring tension is bigger, significantly more than most cases I've seen (just guessing).
Well...
...I have made the occasional drawing here and there...
...some of them even back in the very early days of computer illustrating, like this one of the Japanese World War II-era H6K Mavis flying boat, churned out in the original release of Macpaint, way back in the early 1980's...
...but they were all laborious exercises with computer graphics stuff. (And, note the irregular curve of the back deck of the flying boat.)
Most of what I've done has been of the "draw a straight line with the aid of an electronic ruler (computer)" sort of thing. I'd no more be able to knock out a quick illustrative diagram of skewed clarinet pads that I could play the oboe...
...I have made the occasional drawing here and there...
...some of them even back in the very early days of computer illustrating, like this one of the Japanese World War II-era H6K Mavis flying boat, churned out in the original release of Macpaint, way back in the early 1980's...
...but they were all laborious exercises with computer graphics stuff. (And, note the irregular curve of the back deck of the flying boat.)
Most of what I've done has been of the "draw a straight line with the aid of an electronic ruler (computer)" sort of thing. I'd no more be able to knock out a quick illustrative diagram of skewed clarinet pads that I could play the oboe...
Those diagrams are amazing. They are far more complex and detailed than anything I have done. My pad and tonehole drawing consisted of using Corel Draw to make a large rectangle and a smaller rectangle which I copied. I rounded the corners, put them in position and then tilted the larger one slightly. Then the upper one was moved up and down. Very basic stuff. Someday I will learn everything one can do with the program. Right now my skill level is at the tip of the iceberg.