Mason & Risch was one of the top five Canadian companies. They did, however, like all other manufacturers experience weakness in some of their design features. Mason & Risch had a series of instruments built with a design called the interlocking pin block.

This was the traditional build in the upper framework, but instead of the lag bolts that run through the pin block and out the back plank, they had a series of wedges interlocking the back plank and pin block together across the top of both planks. Unfortunately over time the tremendous weight of the instrument at concert pitch gradually began to pull the upper framework apart. I began to see pin block/ rear plank separations in the mid nineteen eighties and by this point in time very few of the pianos built with the interlocking pin block assembly will be stable. Cnc Symulator Heidenhain Fanuc. One clue is the series is mostly in the five digit serial numbers beginning with number 1XXXX. The second clue will be the decal work on the plate inside with will state; “Patented Interlocking Pin Block Assembly” or something like that. The third clue will be loose tuning pins in the upper part of the block. There will also be the usual statement M&R had on their plates which was “Great is the Privilege of Achievement.” If this instrument is one in that series then I would recommend removing the top bi-folding board to inspect for a separation there.

If there is the remedy is to clamp the top end together, remove the six inch screws one by one and drill through to the back with a long bit or bit and brace, then install 5/8 lag bolts with a nut on the backside. Or ditch that one and find another. Nice cabinetry on that one with the detailed front board and the double legs which are called Corinthian columns.