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I was thinking of how hard it is to make a LEGO piano.

I have already tried to use a rubber band but it did not make a good sound when I plucked at it.

My problem is that I want to make a piano but I don't know what to use for the strings. Can someone help?

chicks
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Nerd
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    And also i want to make a piano in which i can actualy play! I want a mini one that is not to big maybey a little smaller than a laptop keybord – Nerd Jun 18 '20 at 22:36
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    got a hunch it might take a wrench... (youtube) – Uli Jun 19 '20 at 00:57
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    @Henrik: Questions only become untagged if they are migrated or all of their tags get deleted. You cannot create a question without tags. – Wrzlprmft Jun 19 '20 at 07:48
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    @Uli That looks like an answer! – jpa Jun 19 '20 at 10:58
  • @mindstormsboi Nerd said "about the size of a laptop keyboard". Let's compare it to a 32 studs baseplate. Let's take a 2x8 plate for each key on our piano keyboard which gives us 16 keys (we'll ignore the black keys for a moment). That's 2 octaves. Is it possible to determine the position of each key over this distance of 32 studs with the EV3 distance sensor? – Uli Jun 19 '20 at 12:11
  • @Uli EV3 has a touch sensor, which is basically just a button. We could bury it under the key and when pressed down it would detect it. Another upside is that it would already provide the mechanism of popping the key back up. – mindstormsboi Jun 19 '20 at 12:13
  • @Uli Only downside is that an EV3 as well as an NXT can only hold up to 4 touch sensors, so you will need duplicate EV3s connected together via USB if you don't want to individually turn each one on/off or something. – mindstormsboi Jun 19 '20 at 12:20
  • I've removed a number of comments from this thread. If I've deleted your comments, it might be good to review this: https://bricks.stackexchange.com/help/privileges/comment and this: https://bricks.stackexchange.com/conduct – jncraton Jun 19 '20 at 14:37
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    @Uli That piano seems to be an xylophone in disguise, I don't think it's suitable. Let's... lets use mindstorms bricks instead. – mindstormsboi Jun 21 '20 at 11:48

2 Answers2

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Donny Chen made a LEGO piano that I believe is just large enough to play. Details are available on LEGO Ideas. You can watch him show it off in a video from Brickvention 2019. He has it motorized in that video.

Piano

From your comments, it sounds like you are interested in not simply having a piano with keys that can move, but one that actually emits proper sound. I think it will be quite difficult to do that effectively using LEGO elements (string, rubber bands, etc). The best that you can probably do to deliver sound using LEGO elements would probably be using EV3 or BOOST. This would be similar to the guitar model from the BOOST set:

BOOST Guitar

jncraton
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    It is possible to tune rubber bands, but not really at that scale – Chris H Jun 19 '20 at 09:32
  • Indeed, you're kinda lucky if you have 17101 and want to make a piano. I can explain how that guitar in the photo works if you don't mind: The guitar handle is covered in colored tiles, and a studded technic beam goes around it. On the other end of the stick, there is a color/distance sensor. When you move the studded beam up and down, the distance sensor detects it and sends this info to the hub, and then the hub sends the same info again to the app to operate it, which means that your device plays the sound. – mindstormsboi Jun 19 '20 at 10:52
  • The colored tiles are not detected in any way, they are just there to help you to remember the correct positions on the stick to play the correct sounds. – mindstormsboi Jun 19 '20 at 10:53
  • Personally I would recommend EV3 instead though, BOOST quickly gets boring and with EV3 you can do many, many more things. The only downside of EV3 is that it gets tricky when you're trying to make big projects like this sometimes.‮ – mindstormsboi Jun 19 '20 at 11:03
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    @mindstormsboi So this "guitar" really has more in common with a theremin than an actual guitar, being based on distance rather than a vibrating string... – Darrel Hoffman Jun 19 '20 at 13:35
  • Ohhhh... thats actauly a very smart idea @Chris H , using lego boost sensors so that they detect when i push something down – Nerd Jun 19 '20 at 13:49
  • And @Chris H it is possible to tune rubber bands at a scale, you just pull it or twist it until you get the right scale – Nerd Jun 19 '20 at 13:51
  • @Nerd Boost app doesn't have piano sounds I think. You can record them but I think they will come out bad, so just use EV3 instead. The rubber strings don't actually matter at this point (too hard to manipulate, you might as well set up fake ones instead), the EV3 can use buttons and when it detects you pressing them the EV3 itself can play the piano sounds. – mindstormsboi Jun 19 '20 at 14:14
  • @Nerd having tried it recently (making a functional "guitar" with a biscuit tin, not Lego) I knew it wasn't going to work well. You're technically correct, but with (fairly thin) rubber bands and using technic to put a tuning peg 12 studs from a bridge the tension one a single band was high enough to pull bricks apart by the time I got near A440. So you'd need a lot of reinforcing for an octave. I also found that rubber bands don't stay in tune for long. A little strumming and they creep/warm up enough that the pitch drops. By "scale" I meant Lego/model proportions, not musical scale BTW – Chris H Jun 19 '20 at 14:38
  • Ok thanks @ChrisH – Nerd Jun 19 '20 at 18:02
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There is this monstrosity as an example on the internet, which proves that you can work with proper metal strings. But your biggest enemy will be the huge tension everything is under. There is a reason that proper pianos have steel frames. As you only want one or two octaves, you can probably do without reinforcing the frame, but wherever the strings terminate will be a single point of failure. Apparently the harpsichord in the example uses some mutilated pieces there (though the only mention of glue is for the lid).

Also note the sound example. In any string instrument, sound is generated by the combination of the string and the resonating body of the instrument itself. In other words, it will always sound "plasticly" and there is nothing you can do about that.

mlk
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