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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
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Yamaha PF 1000 piano , 2002
Do they want repairers to use the included ,single, off-centre steel rod
prop, when the top is open , to slip out of the next to non existant holding position on the floppy drive housing , so they do fatal damage when the whole wooden top with main pcb and display etc, crashes down? A bit of a workup disconnecting wiring looms and screening cover but a hell of a lot safer for collateral damage and personal safety, totally removing the top section. |
#2
Posted to sci.electronics.repair,alt.music.makers.electric-piano
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Yamaha PF 1000 piano , 2002
2 of the keys are sticking, because the plastic has warped with time or
temperature. Instead of internal dimension of 18.7mm the underside open width is now about 18.3mm where it abuts the static pillar and rubs against it. Any recognised safe method of locally heating or something that will accurately realign the plastic and retain reformed shape? the throw on one side is likely different to the other side so needs taking into account. |
#3
Posted to sci.electronics.repair,alt.music.makers.electric-piano
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Yamaha PF 1000 piano , 2002
"N_Cook" wrote in message ... 2 of the keys are sticking, because the plastic has warped with time or temperature. Instead of internal dimension of 18.7mm the underside open width is now about 18.3mm where it abuts the static pillar and rubs against it. Any recognised safe method of locally heating or something that will accurately realign the plastic and retain reformed shape? the throw on one side is likely different to the other side so needs taking into account. I have tried heating deformed keys with a hot air gun, and found it very difficult. If you are very careful you can just about pull things into a different shape if it is fouling something, but I found heating of a large area often reults in the plastic shrinking and the key becoming too short to fit/work at all. Different plastics may have different properties though, these were old Roland keys no longer available. Also there seems to be a fine tolerance between getting the plastic pliable enough to remould, and so pliable it runs into a goo, which you have no hope of moulding back to shape. A temperature controlled oven is probably your best bet,k and you will need a lot of practice on something disposible first. Gareth. |
#4
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Yamaha PF 1000 piano , 2002
Gareth Magennis wrote in message
... "N_Cook" wrote in message ... 2 of the keys are sticking, because the plastic has warped with time or temperature. Instead of internal dimension of 18.7mm the underside open width is now about 18.3mm where it abuts the static pillar and rubs against it. Any recognised safe method of locally heating or something that will accurately realign the plastic and retain reformed shape? the throw on one side is likely different to the other side so needs taking into account. I have tried heating deformed keys with a hot air gun, and found it very difficult. If you are very careful you can just about pull things into a different shape if it is fouling something, but I found heating of a large area often reults in the plastic shrinking and the key becoming too short to fit/work at all. Different plastics may have different properties though, these were old Roland keys no longer available. Also there seems to be a fine tolerance between getting the plastic pliable enough to remould, and so pliable it runs into a goo, which you have no hope of moulding back to shape. A temperature controlled oven is probably your best bet,k and you will need a lot of practice on something disposible first. Gareth. In the next hour I will tackle this. Have something like a 30 amp ceramic connector block with the metal part removed and hole large enough to take a brass cased thermometer wedged inside with key laid sideways on a large PTFE slab. This ceramic small enough to go inside plastic recess and only touch the one face most deformed. Starting at 60 degrees from hot air I will increase by 10 deg steps , measuring with Vernier each time. |
#5
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Yamaha PF 1000 piano , 2002
I had previously swapped the erroneous keys with relatively unused top
actave ones , showing it was a key problem , not guide pillar or pivot problem. They still stick in new position but if I make matters worse its not too disastrous |
#6
Posted to sci.electronics.repair,alt.music.makers.electric-piano
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Yamaha PF 1000 piano , 2002
"Gareth Magennis" wrote in message ... "N_Cook" wrote in message ... 2 of the keys are sticking, because the plastic has warped with time or temperature. Instead of internal dimension of 18.7mm the underside open width is now about 18.3mm where it abuts the static pillar and rubs against it. Any recognised safe method of locally heating or something that will accurately realign the plastic and retain reformed shape? the throw on one side is likely different to the other side so needs taking into account. I have tried heating deformed keys with a hot air gun, and found it very difficult. If you are very careful you can just about pull things into a different shape if it is fouling something, but I found heating of a large area often reults in the plastic shrinking and the key becoming too short to fit/work at all. Different plastics may have different properties though, these were old Roland keys no longer available. Also there seems to be a fine tolerance between getting the plastic pliable enough to remould, and so pliable it runs into a goo, which you have no hope of moulding back to shape. A temperature controlled oven is probably your best bet,k and you will need a lot of practice on something disposible first. Gareth. Oh, and boiling water is not hot enough unfortunately. Gareth. |
#7
Posted to sci.electronics.repair,alt.music.makers.electric-piano
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Yamaha PF 1000 piano , 2002
Gareth Magennis wrote in message
... "Gareth Magennis" wrote in message ... "N_Cook" wrote in message ... 2 of the keys are sticking, because the plastic has warped with time or temperature. Instead of internal dimension of 18.7mm the underside open width is now about 18.3mm where it abuts the static pillar and rubs against it. Any recognised safe method of locally heating or something that will accurately realign the plastic and retain reformed shape? the throw on one side is likely different to the other side so needs taking into account. I have tried heating deformed keys with a hot air gun, and found it very difficult. If you are very careful you can just about pull things into a different shape if it is fouling something, but I found heating of a large area often reults in the plastic shrinking and the key becoming too short to fit/work at all. Different plastics may have different properties though, these were old Roland keys no longer available. Also there seems to be a fine tolerance between getting the plastic pliable enough to remould, and so pliable it runs into a goo, which you have no hope of moulding back to shape. A temperature controlled oven is probably your best bet,k and you will need a lot of practice on something disposible first. Gareth. Oh, and boiling water is not hot enough unfortunately. Gareth. Just short Using my ceramic block method, melting point around 105 to 120 degree C. Opened up one side about .1mm and worse sticking although the "correct" side to compensate , but more convincing now a rotation problem along the key axis. I'd just allowed the key to rotate more. Hopefully such slight melting will be recoverable now real reason of failure found. I'd noticed these keys removed and replaced easier , and didn't seat well, than the good keys so now assumed a wear problem at the pivot end. Found some ball bearings to take measurements from good and bad key recesses with Vernier callipers. Cleaning off the grease inside , a part of the pivot end housing broke away. I've previously repaired Yamaha keys on a different piano that had been kicked over - moulding repacement sections as original flaked off parts missing in the original incident. This one must have been cracked but holding together enough to use /remove/ replace but not locally clean. The other one on very close inspection a short crack visible and stressing remainder opened up more of the crack. Will capilliary superglue and reinforce with "hot melt soldering" in the non contact areas of both key breaks. Crack on one face allowing the key to rotate on the pivot slightly, then rubbing action at the play end. |
#8
Posted to sci.electronics.repair,alt.music.makers.electric-piano
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Yamaha PF 1000 piano , 2002
"N_Cook" wrote in message ... Gareth Magennis wrote in message ... "Gareth Magennis" wrote in message ... "N_Cook" wrote in message ... 2 of the keys are sticking, because the plastic has warped with time or temperature. Instead of internal dimension of 18.7mm the underside open width is now about 18.3mm where it abuts the static pillar and rubs against it. Any recognised safe method of locally heating or something that will accurately realign the plastic and retain reformed shape? the throw on one side is likely different to the other side so needs taking into account. I have tried heating deformed keys with a hot air gun, and found it very difficult. If you are very careful you can just about pull things into a different shape if it is fouling something, but I found heating of a large area often reults in the plastic shrinking and the key becoming too short to fit/work at all. Different plastics may have different properties though, these were old Roland keys no longer available. Also there seems to be a fine tolerance between getting the plastic pliable enough to remould, and so pliable it runs into a goo, which you have no hope of moulding back to shape. A temperature controlled oven is probably your best bet,k and you will need a lot of practice on something disposible first. Gareth. Oh, and boiling water is not hot enough unfortunately. Gareth. Just short Using my ceramic block method, melting point around 105 to 120 degree C. Opened up one side about .1mm and worse sticking although the "correct" side to compensate , but more convincing now a rotation problem along the key axis. I'd just allowed the key to rotate more. Hopefully such slight melting will be recoverable now real reason of failure found. I'd noticed these keys removed and replaced easier , and didn't seat well, than the good keys so now assumed a wear problem at the pivot end. Found some ball bearings to take measurements from good and bad key recesses with Vernier callipers. Cleaning off the grease inside , a part of the pivot end housing broke away. I've previously repaired Yamaha keys on a different piano that had been kicked over - moulding repacement sections as original flaked off parts missing in the original incident. This one must have been cracked but holding together enough to use /remove/ replace but not locally clean. The other one on very close inspection a short crack visible and stressing remainder opened up more of the crack. Will capilliary superglue and reinforce with "hot melt soldering" in the non contact areas of both key breaks. Crack on one face allowing the key to rotate on the pivot slightly, then rubbing action at the play end. IMHO you'd do a lot better buying new keys and charging the customer for them, but whatever floats your boat I suppose. Gareth. |
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