Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum About jack to knuckle alignment...

When I try to adjust the jack position using a slotted screw driver, the letoff dowels are in the way. The screwdriver shaft is too thick to fit in the narrow spaces between the letoff dowels. I can't gain access from the top of the dowels either. This is in a Yamaha G7.

I have run into that myself. Whoever thinks being a piano technician is easy is kidding him/herself.

Some tools are thinner than others. You need a new tool.

Pwg

Sometimes let-off dowels are attach to a rail screwed under the hammer rail, you can see small screws between hammer flanges or sometimes the hammer flanges had a notch for the screw, if removed you can take out a section of let off dowels, i suppose that you are doing jack alignment before let-off.

This is funny I'm currently doing a DIY piano action regulation and stumbled upon the same problem two days ago and invented my own tool which I described in the digital piano forums, thinking that professional here have a special tool for that but it seems my solution might help.

So, basically I purchased a set of very thin and long screwdrivers that are made of an alloy that's not very hard and I could cut and file them. On the right is an unmodified screwdriver, in the middle is one that I cut through with a hacksaw and then extended each "horn" by inserting another screwdriver in the slot. (And on the left is a capstan and jack button tool that I made by sharpening another screwdriver and then twisting it)




So, with this tool and since it's a bit widened, it's possible to insert it between the jack buttons at an angle and still turn the screws. I basically aligned all the jacks under the knuckles and it was very helpful. Here's how it looks:


For whoever is interested, I also made my own key dip block from a white keytop and a woden block, as well as aftertouch gauge from a 1mm thick plastic:

Thank you for all the responses here! Could anyone please point me to a link where I could purchase the tool? Maybe I could buy one before I try to make my own tool.

I clicked on that picture and then something ugly happened to my computer. A warning that my computer is blocked and I should call a phone number witihin 5 minutes. It pretended to come from windows support center. Be careful!

Sometimes you can manually lift the whippen to the point where the adjuster is accessible just above the dowels.
Other times, if you are doing many, you can remove the whole hammer rail with the hammers and dowels attached. All the adjusters are completely open then.

Or the wippen rail. Either way, you may have to adjust the jacks at the end of each section by removing their wippens first.

Pianotek tool #JJS-1 is a good tool.

HOWEVER...
They also sell a tool for a combination handle: JCH-19 that is useless as a jack adjustment tool because the shaft is much too big. It turns out its perfect for spade type let-off screws that you find on some asian pianos. I believe that is what it is intended for, but is mislabeled in the catalog.