Upright piano regulation

[mfield1203]

Hi there, first post to the forum so hopefully it's all going to work!

I am putting up this post to get some advice about the regulation procedure for an upright piano that I have. I know that I could call in a tech but that would cost more than I am willing to spend (I'm a student!) and the piano I have isn't some expensive model that's new from the showroom; it's an old Collinson & Sons, straight strung, 85 key upright from around the 1950s I believe, so it doesn't matter to me if I accidentally break something during the learning process - plus I have a spare action and ivory keys from a similar piano that was demolished so I can get away with getting replacement parts easily :) Anyway, enough rambling, back to the main point! I have watched a series on YouTube by Howard Piano Industries (Steve Howard) that shows how to regulate the action within an upright piano - Steve's videos have been a massive help, however I have a few problems which the videos do not seem to address.

I have picked 5 keys to regulate as a sample (Middle C, C#, D, D# & E). I have removed any lost motion in the keys by adjusting the capstans. I have set the hammer blow distance to 46mm by putting some felt between the hammer rail and the back rail (the part that moves the hammers closer to the strings when using the left-most pedal - I don't quite know how else to explain it) and have tried to set the let-off to 3mm by ajusting the small regulation button. This is where the problems occur. When I press the key softly to measure the let-off, the hammer falls against the string and bounces slightly. I've tried adjusting the let-off regulation button many times to no avail. The keys play just fine when struck at normal velocity but for some reason, playing softly produces a double strike and the hammers seem to fall dead against the strings and limit the string from sounding slightly. I would also like to know if the parameters for the regulation are ok for a standard upright?

Any help would be greatly appreciated - I am trying to get some playability out of it since it seems to hold it's tune fairly well (I'm no expert by any means but have tuned with Tunelab) so would like to atleast make it semi-good standard for the average player.

Many thanks in advance,

Mitch.

[vernon]

As it's straight strung don't expect too subtle results.
Take out the keys and make sure all the felts under are the same and sound.Remove damper rail.Make sure the action is firm in it's mounting and can't move to and fro or up and down.
bend all the checks back slightly with your thumb to avoid compromising the next moves.
Adjust the set-off to 1/8th inch.by raising the section with your finger. Made sure the jacks don't bind on the slap rail if there is one. Also that the thin slap rail is not grossly warped.
Replace keys and remove lost motion. Check touch(dip) is 3/8th inch.Play notes firmly and push in the checks in with your thumb so the hammers check about 5/8 " from the string.
Replace damper rail and adjust lift as best as possible as the damper lift rail will probably be warped.Ensure dampers are resting on the strings and not on the small button on the end of the damper wires.
Bob's yer uncle.

[Colin Nicholson]

some good advice there from the expert....

Is the piano action over-damped??

Just a couple of guides (may be helpful).... if the hammers are double striking (I call it 'bubbling') when playing softly, try removing a card washer from under the front key's baize washer.... if there are any card washers? OR bash the baize washer with a hammer onto a solid floor to squash it slightly. Check the key dip (distance when pressing down on the key) is about 9.5mm.... increase it to 10mm if needed. If all fails, you might need to replace the hammer balance leathers if worn, or/and the back check felt.... to get a uniform touch. You sometimes have to throw measurements out the window if the action materials are worn, and just rely on adding/ subtracting key frame washers, and bending the odd wire here & there for a better result.

Make sure the key frame is not thick with dust.... if there is compressed dust on the front baize washers, this may reduce the key dip and cause double striking. Also check that the keys are reasonably level.

When I was taught.... I was told the standard hammer distance (blow) was 47mm. (It might make a difference) It's important you get the ratio 5:1 correct first before doing set off/ lost motion/ checking etc. So if the key moves down 9.5mm.... multiply 9.5 by 5 to get the hammer blow.... works out at 47.5mm, but also depends on how deep the hammer felt grooves are? .... the tip of the hammer felt / outside edge is not the part that comes into contact with the strings.... if the grooves are about 1-2mm, then adjust accordingly.

Lost motion...... always allow a tiny bit of movement from the back check first, before the hammer moves.... so the back check 'winks' slightly first (hammer not moving).... this allows the jack to slide back under easily.... if the two are moving at exactly the same time, then wind the capstan clockwise a tiny amount.... so to avoid any jacks catching.

Hammer checking is about 16mm (metric!) from the string .... stick your index finger between the gap.... should be about right. If it still double-strikes, remove another washer.... and so on.

Set off.... sometimes depending on wear & tear, the button felts will be dented slightly as they press on the jack knuckle (toe).... so when you turn the screws, the dent changes position, and often the toe rides on the 'uphill' of the dent.... so don't expect perfection here.... and if the leathers are worn, or back checks misaligned with the leathers.... some prelim action repairs may need to be done.

Make sure the hammer reaches about half its travel (c.25mm) to the string before the damper starts to lift off. Bend the damper spoons (if under-damped) or gently wind in the lift rods (if over-damped) so there is a small gap between the end of the lift wire wooden dolly and the top surface of the undercarriage.

Get that ratio right first.... for all keys & hammers and you should see a difference.

[vernon]

I just said all that!
Forgot to warn that turning the set off buttons sometimes presents an unused bit of felt that produces the opposite effect!.
That's the problem about giving DIY advice as with experience we check things and do things subconciously without realising it's experience that guides us.You can;t fit all the bits into a book.
Colin, as you know, if a customer phones up with a problem, by the end of the conversation you problem know the answer.
Recently, a customer told me his piano that I'd sold him 2 months previously( a lovely Kawai) had 2 sticking notes.
me; " Are the keys sticking down or the hammers sticking up?
answer; keys sticking down.
me Are they two adjacent white keys?
answer. Yes.
me Then you've dropped something between them.
answer Certainly not.
I called in the passing a removed several large biscuit crumbs. 2 minutes . problem solved. No charge!

me; Keep the children away with their snacks.
answer; Thay are not allowed near the piano with snacks.

Wee Win kie strikes again