Zorba's "Secret" Piano Page
The Pie-Anna!
Caster Replacement
30 October 2011
Warning: This is a VERY dangerous job. Do NOT attempt this yourself unless you know what you are doing AND accept all responsibility for any and all risks associated therewith! The accepted practice in the piano service industry is to lay the instrument on its back, preferably with a piano tilter - not jack it up as done here. In order to do the job as depicted here, you MUST make your own jack in order to very carefully lift the piano a small amount at a time. The piano was NOT particularly stable the entire time it was on the blocks nor was it stable when lifting it with the modified jack! In addition, it was necessary to place additional weight on the jack (i.e. hold it down) as it wanted to lever up from the weight of the piano.
The author assumes NO responsibility or liability for the use or misuse of the information below.
PROCEED AT YOUR OWN RISK.
My latest eBay acquisition: A stringing crank. I'm thinking I'll eventually
restring this thing, found this one from a tuner's estate for a good price.
A small hydraulic trolley jack that has been modified specifically for this job.
Lift one end of the piano at a time. NOTE: Staged picture, as the jack took
the piano's weight, it was necessary to bear down on the back end of the jack
to keep it on the ground, thus actually lifting the piano rather than lifting
the 'ass end' of the jack. VERY DANGEROUS.
Put a block of wood under it. NOTE: The jack was NOT bearing any weight at the
time this picture was taken. VERY DANGEROUS.
Repeat on other side with larger block...
Back on first side with yet larger block.
Largest yet.
And final shim on first side for lifted and level piano!
NOTE: The piano was unstable at this, and every other point
of this procedure. VERY DANGEROUS.
Original cast iron caster.
The recess it came out of. I was unable to photograph the inside of same.
New caster in place.
End on view. Too tight a fit. See text.
Contrast original caster (bottom) with socket for new caster. Same screw pattern!
New socket showing wood bushing to make up the difference in diameter.
Wood bushing in place on socket.
Top view of assembly.
Old (left) and new casters.
Caster in place on floor
While I had the piano on blocks, I drilled a hole in the bottom board
to allow the cord for the music reader computer to exit cleanly.
Cord pulled through.
Music reader pedals in place. The wireless dongle they plug into now fits
under the piano where it belongs due to the slight increase in height.
Warning: This is a VERY dangerous job. Do NOT attempt this yourself unless you know what you are doing AND accept all responsibility for any and all risks associated therewith! The accepted practice in the piano service industry is to lay the instrument on its back, preferably with a piano tilter - not jack it up as done here. In order to do the job as depicted here, you MUST make your own jack in order to very carefully lift the piano a small amount at a time. The piano was NOT particularly stable the entire time it was on the blocks nor was it stable when lifting it with the modified jack! In addition, it was necessary to place additional weight on the jack (i.e. hold it down) as it wanted to lever up from the weight of the piano.
The author assumes NO responsibility or liability for the use or misuse of the information presented here.
PROCEED AT YOUR OWN RISK.
Have you gotten the point that the way I did this is VERY DANGEROUS?
Go back and read the above sentence, and the above warnings again, please.
With all this said, the pictures pretty much explain the job. I was fortunate in that the new casters have the exact same screw pattern as the old - this isn't always the case. The new casters also fit into the old holes - this isn't always the case.
HOWEVER -
I'm going to get to do this over again, as the tops of the new casters just barely touch the bottom wood of the piano, thus preventing them from turning - a fairly common occurrence I'm told. Two ways to fix it: 1) Route out a bit of wood to allow room for the caster to turn, or 2) Install a shim washer under the sockets. I'm going with #2 as it will be easier for my skill set; it will be safer as routing wood from the bottom of the piano propped up on unstable blocking is a good way to get killed; AND I'm not too happy with the tightness, or lack thereof, of some of the caster screws. Need new, longer ones.
It does, however, roll very nice and easy with the new casters; I just can't change direction until I get them shimmed!
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