How does a coil setter/tightener actually work?

I've been wondering about tools such as Schaff's "coil tightener" (3155)


and "coil setter" (175)
.

The coil tightener has a half cut-out that, as far as I can see, fits around the coils, while the tuning pin fits into the hole. I've seen such a tool in action, e.g. in the following video, at 2:10
http://www.youtube.com/watch?v=TK7tkEpEB9g&list=PL550F1747A716EEA7&index=33
The technician hammers on the tool, but I cannot see how the hammer blow would actually be transferred to the coils, because the tool fits around the outside of the coils. It doesn't rest on the top-most coil.

Similarly, I understand that Schaff's coil setter, with an internal diameter of 5/16", does not rest on the top coil, but actually fits over the coils. Sure, it would eliminate overlapping coils, but I can't see it actually snugging up the coils against each other, from the top down.

So what do these tools actually do? What's the use in hammering them, if they don't transfer the blow to the coils?

Hi Mark - the coil tightener actually goes under the coil. A slide hammer is then used to tighten up the coil going up. Sometimes it's hard to get the tool in place in between tightly spaced pins, but when it does go in place it works really well. It doesn't touch the plate, so no marks are made in the gold paint.

The only problem I've had is that that the tool is prone to cracking. I've gone through 3 or 4 of them over the years.

I don't know about the other tool. I've got one that I inherited from my dad, but I've never used it. Chuck

Greetings,
If one strings without a protruding becket, the technique for the most stable coils is to wind them on the pin as tightly as possible, and make sure that they are above the becket hole on the "non-entry' side of the pin. After chipping the strings to up near pitch, the coil setter is used to tap the coil down, leveling it as it tightens the coils against each other. If you want your stringing to be even, this step is just as important as leaving all the pins at the same height.
Once the coils are snugged up, there is still a lot of slack in them, as the string tension is held increasingly by friction on the pin rather than elastic stress of the wire beyond the first coil. The coil tightener has a internal "cone" shape that is designed to mash the top coil inwards, flattening the bend of the becket, and moving some of the top-string's tension farther up into the coil.

In theory, the becket will never see as much tension as the speaking length, since the coils friction lessens the strain, and it isn't possible to put enough tension in the string to bring the top coil's tension up to speaking length tension without breaking the string. There is still anywhere from 100 -200 cents of slack in three coils when the string is brought up to pitch. This will either "bleed" down during the first 5 years of tension, or it can be greatly accelerated with the use of a small pair of Vise-Grip pliers with a small concavity ground on their jaws.

I use mine by setting the grips so that it is just short of locking, which gives me the greatest leverage. I squeeze them down so that they flatten the becket into the hole, and then with heavy pressure still on the coil, I twist the counter clockwise, massaging the coil in a flattening direction. This will usually drop the note by at least 100-200 cents, greatly shortening the break-in period of a new string.
Regards,

...and if left undone, the resulting drop in pitch over the first few years is what so many people think is "the strings stretching".

I use #171 by putting it over the coil and wobbling it around the pin, which pushed the coil closer to the pin. Sometimes I will use it to tap on the top of the coil to push it down, but the tool that I use for that is #3101 (on the previous page), which has a slide hammer which taps down or pulls up. I have modified mine by grinding the sides of it off so it fits better between the pins. Actually, I would like to have another tip on it that would just be a stringing hook, but the proper hardening and tempering is difficult.

Stringing hooks and coil lifters are the main tools that I use. #3101 is used to take out the looseness in the coils that is left when you do the final tightening.

Thanks for all the replies.

Dan, I believe you had the two tools of my opening post confused with the impact coil lifter, Schaff tool no. 3101. But not to worry.

Ed, I didn't know that the inside of a coil tightener is conical. That clarifies things a lot.

BDB, you've mentioned your modification of 3101 before. I'd be very interested in one or two pictures, if you have the time to make some.

Ah, I don't think I am in this one Mark. Maybe Chuck you were addressing?

Has anybody used the coil lifter that Bolduc sells?

Here is a photo.

https://www.facebook.com/photo.php?fbid=...e=1&theater

Jurgen , I tested how much the wire move if the coil is worked with plier, but after my usual way, with becket well inserted.

Did not notice a huge drop , you stated 1/4 tone, not what I experienced.

However, once the piano is up to pitch and tuned , coil setting , from below and/or above, lower the pitch and strenghten /clear the tone.

Even if the coils have been set and hammered once at the end of the stringing job.

Quite right, my apologies, Dan.

Hey Mark - I'm indeed mixing up my tools! I looked at the picture you posted and wondered why it didn't show the rest of it! Well, that explains it. (Someday down the road when you're in your 7th decade you'll understand.) Sorry about the confusion.

The impact coil tightener (or slide hammer, as I always called it) is the tool of choice in my opinion. The one I have was purchased from Schaff in the early '70's and has a bigger weight on it than the new ones the sell. That and a pair of pliers to squeeze the beckett in solid is all you need in most cases to make a really tight, attractive coil. Oh, and a mallet and a flat-bladed medium sized screwdriver to tap down from the top if need be. Chuck

The other tool is to break the becket, it works but I dont like too much the process (to take out the strings)

A good hammer stroke and the becket is broke

A string hook and/or lifter, and a brass tipped blade similar to a flat screwdriver is all I've ever used and the coils end up level and tight. Paying attention to how the coils first take on the pin greatly reduces any massaging needed later. Really, is there a need for a better mousetrap?

'Funny. I inherited the same tool from MY Dad, and finally put it to use as a pin driver with my air hammer. I put a soft steel screw up in it with the head pointing outward. After a few blows the screw head conformed to the shape of the tuning pin top and I had a driver that wouldn't mar the pin. There are probably more elegant ways to do that, but it works for me.

the lighter jab on the coils when the note is tuned is a big help to raise power and clean the tone.

If possible with an inertia coil lifter, but the one I have is not always thin enough to go between the coils.

SO there is some loss only due to the lower coil opening when the piano is bring to pitch and tuned. (plus possibly some stretch of the wire when the coil is impacted.

Just try it for yourself and tell us what you find.

I have one I baught as a "coil becket breaker", possibly from Pianotek, I dont remind.

Here is a drawing of the material I took off the slide hammer tool:



The area removed is outlined in red.

Ah, thanks for taking the time, BDB! I'll keep that in mind if (or when) I place my next order on Schaff.

I'm no stranger to taking my grinder to Schaff's tools. Their bent backcheck regulator, # 472, did not fit in-between the backcheck and bridle wires of a single piano I tried it on, until I ground away most of the metal between the slots.

You can see what the HellerBass package is used for.

The video shows how a guy with perfect self control can install new strings. The one that are emotive use finger and palm protection, or some product on hands to avoid perspiration (as he probably does).

One have to have an extra strong/supple back and bone for such kind of jobs.