QRS PNOscan II Installation Manual - page 15
P N O s c a n
P N O s c a n
P N O s c a n
I I
I I
I I
I n s t a l l a t i o n M a n u a l
I n s t a l l a t i o n M a n u a l
I n s t a l l a t i o n M a n u a l
Manual Rev. 1.18
15
QRS Music Technologies, Inc. / Technical Support - 800-247-6557 / www.qrsmusic.com
G] Setting the Proper Key Scan Assembly Height
Now that the proper Key Scan Assembly’s front to back and bass to treble position is secured to the track,
and with the track secured to the key frame, the proper height of the optical sensors can be set. It is very
important for good performance that the distance between the sensors and the key bottoms is set
correctly. Depending on the model of piano you will find that the sharp keys generally dip lower than the
natural keys. For this reason we will use the sharp keys as our point of reference for our height adjustment.
Use the included shims to establish the correct height. More shims can be added under the rear of the
mounts to adjust the angle of the sensors to match the key angle.
1. Place a few sharp keys across the keyboard. Don’t place any above the mounting screw positions.
2. Loosen the #4 x 3/4" mounting screws and add the necessary shims as you establish the required
height measurements across the keyboard. See Figure 18.
3. Add shims under the Track Mounts to set the gap from the Optical Sensors to the bottoms of the sharp
keys at about 0.060” [the thickness of two credit cards].
4. Add extra shims, the smaller size, to tip up the rear of the Key Scan Assembly to conform to the slight
angle of the keys.
By fully dipping the sharp keys and measuring the gap between the sensor and sharp key bottoms you
can establish the vertical setting of the Key Scan Assembly. Use feeler gauges or a known thickness of
cardboard to measure the gap. The typical credit card is 0.030” or should be considered the smallest gap
you would allow. Two stacked credit cards would create the ideal gap. The typical business card would
create only one fourth of the minimum required gap.
When pressing a key for measurement use just a medium force to ensure you are pushing into the
felt dip washer.
Use care when establishing this vertical setting that the key cannot strike any part of the Key Scan
Assembly. The most likely place where this can happen is at the connectors, located at three
places on each of the Key Scan Boards. In many cases adding more shim to the back side of the
scan rail mounts and less to the front during height setting, will help achieve a good gap distance
while avoiding contact with the rail assembly.
In rare cases you may need to notch the bottom of the key in the connector areas to eliminate
contact. This must be considered for allowance of action wear in which will cause the keys to dip
deeper after break-in.
Sharp Key-Depressed
Figure 18
Set the gap from the Optical Sensor to the Sharp
key at 0.060” about the width of two credit cards.
Thick shim
Thin shim
Add more shims at the back so that the
key sensor boards are parallel with the
depressed key.