Digital Piano Repairs

[SEGACDX]

I got this Piano a few weeks ago for about 150$ and wanted to fix it up but this bastard is a pain in the ass.

Even though it’s quite will made for something form 92 it’s just hopeless without new parts.

Luckily nothing electronic is broken other than the volume slider but a big part of it is these dam rubber caps the keys sit on!

They cause the keys to stick or squeak making playing it a real unpleasant experience, I have tried greases and oils to lube them up and ether they make it worse or only work for a short while, It seems replacement is the only option.

If anyone can help me get a replacement for these caps I can use this thing and be done with it.

I have uploaded images of the caps.

I can measure the caps if needed.


Images can be found here ---> http://imgur.com/a/tkw1U

[kripton2035]

well a good investment could be a 3d printer ?
or make your own cap providing a 3d file here : http://www.shapeways.com/create?li=home-create

I also bought some times ago polymorph plastic balls that melt at 60°C and are solid at room temp. easy to build things with that
http://stores.ebay.fr/BlrTronics?_rdc=1

[SEGACDX]

I thought about it but it’s not an option, I need something prefabricated.

[G7PSK]

Have you tried some pure silicone spray, not grease or oil formulations just silicone as used in the plastic injection world, onece you have put that on nothing sticks.

[SEGACDX]

I've tried that too, I need physical replacements not temporary quick fixes.

[peter.mitchell]

have you tried takign thew caps off and just putting a bead of silicone/caulking on them?

[dfmischler]

The pictures didn't show me the geometry of how the key activates the switch.  Remember, we haven't seen it live and close up so we need both the big picture of how things go together and the details.  I assume that the key must slide slightly over the "cap".  If so it is probably important to get the right material.  For example, some sliding on a nylon to nylon joint would be practically self lubricating.

Maybe you should provide some pictures that really show us what you are talking about:  a key and "cap" in situ from a useful angle, and a "cap" removed from the switch from the important sides, and big enough to really see it.  We still might not come up with anything useful, but at least we will have been infotained 

[SEGACDX]

I hope this helps.

http://imgur.com/a/KtjG0

[fpliuzzi]

Hello, I know that you stated that you were looking for physical replacements and not temporary quick fixes, but maybe this falls somewhere in-between the two...

The 4th photo you supplied was particularly useful. If the rubber bumpers have expanded with age, it looks like they would wedge themselves into the openings in the plastic keys when the keys are fully depressed. If a key is only rubbing on the two sides of the rubber bumper, maybe you can wet-sand the rubber with a fine grit paper to take a tiny bit of the rubber off to give the part more clearance while the key is sliding up and down on it.

Actually, if the rubber is hard enough it may pay to slightly wet-sand the face, plus the two sides, of the rubber for a better slip fit in that channel of the plastic key.

Obviously, this predisposes that the rubber isn't too soft or overly sticky. Good luck with your keyboard.

Regards,
Frank

[G7PSK]

You might also find that new ones would also be tight as many plastics shrink with age. Would it be possible to make a mould say from plaster of paris and then use a silicon rubber mix to make new ones. The other thing might be to use felt for the job which is what is used on real pianos for key dampers if you go to a piano repairer I would expect that they have a suitable felt or other material for the job. 

[SEGACDX]

I did think of that and I think that may be the best option, Felt should do it but I'll have to put another few days of work into it.

The rubber caps have expanded that is true, I have tried taking off some of the rubber with a soldering iron and most keys work way better but a few just won't stop getting stuck and squeaking!