Directions to obtain an even touch in Blüthner grand pianos with Erard action.

The basic measurements of a Erard - Roller action is based on a touch depth of 10 mm and a blow of 47 mm For precise adjusting the following procedures have to be gone through:

1. Lining up of the action parts
The screws of the hammer flanges and those of the whippens should be tightened. Then the hammers are to be spaced under the middle of the strings. Now the whippens have to be aligned with the hammer shank, keeping the saddle in the middle of the capstan. Little deviations can be corrected by putting strips of paper behind the whippen flange on the appropriate side .The hammers have to travel parallel when being moved up and down. A correction is possible by putting a strip of paper under the flange right or left of the screw.

2. Fitting of the key frame
The key frame has to rest snugly on the key bottom . This is controlled by tapping on it. The hollow lying parts have to be flattened . The gliding bolt screws should just touch the key bottom. To control their position press with your fingers on the hammer rail. If the keys move downwards there is still a gap between the regulation screws and the bottom.

3. Regulating the action
The upper edge of the jack should recede 1/ 10 mm from the repetition lever. There is a screw to adjust this.

To give the jack the maximum attack on the roller the backside edge of the jack should be in line with the back side of the core of the roller.

The keys are levelled to a height of 71 mm measured from the key bottom.

The let- off is adjusted by turning the let- off dolly to make the hammerdrop away at 1,5 mm from the strings.

The dip of the end keys in every section is adjusted to 10 mm by putting paper washers under the touch baizes. Then the blow of the corresponding hammers is adjusted by turning the capstans so that they are released when the key just touches the baize.

The action is now taken out of the instrument and put on a flat surface and the remaining hammers are brought to the same height as the trial hammers.

Then the action is put back again and the key dip regulated for the remaining keys by comparing the feel of the touch. All hammers should only release when the key just touches the baize. Thus also the dip of the sharps is regulated.

The back-checks are evenly spaced on the middle of the hammers. The surfaces of the back checks should be parallel to the hammer mouldings. Then the back check is bend so close to the hammer to stop it on the middle of the felt of the back- check.

The repetition spring can either be regulated with the screw at the end of the repetition lever ( long spring ) or it has to be bend up or down with a hook.

The hammer being caught by the check should slowly move up when the key is released.

The drop screw is adjusted to let the hammer fall back 3 mm from the let- off point.The action is put on a flat surface and the hammers are turned up approximately 3 mm to feel the after touch. This will be about half a turn of the capstan.

The damper wires have to travel lightly through the guide rail. The keys should lift the dampers when being lifted 5 mm. This can be regulated by letting the wires go deeper in the damper block, or by bending the spoons if there are any.

The lift is adjusted with the capstans underneath the damper levers.

The damper check rail should allow 1 mm space for the damper levers when the black keys are pressed down.

To adjust the side way shift of the action when pressing the left pedal turn the screw on the right side in the key bottom. When the pedal is pressed the hammers should touch the strings in between the grooves which are formed by the blow of the strings.

The damper lift is correct, when the double wedges are 1 mm above the strings when the pedal is activated. It can be adjusted at the stop screw on the pedal lever.