Ι've been playing 61 keys non-weighted keyboard for 3 years with the sole purpose of learning piano. But as Ι improved, I wanted to learn more and more difficult tracks which included 0th and 6th octaves; however 61 keys were simply not enough. I always wanted to buy a hammered digital piano with 88 keys but couldn't afford it due to financial difficulties. Now, the question is, how long will it take for me to adapt to new hammered keys if I buy a new digital piano today? Will all my efforts until now be in vain? Thanks alot in advance
You are likely to encounter a bit of difficulty with this because weighted keys are harder to push down. Basic keyboards typically have very light keys with minimal resistance and are far less tiring to play.
The solution to this is to treat it the same way as any other strength/endurance problem — back up to the speed or amount of playing where you are comfortable and able to maintain good form, and gradually increase.
I don't think that learning dynamics is as easy as Daniel's answer makes out, but it's not the end of the world either. Playing well requires more than just emotion — you will need to apply focused technique to bring out the volume and feeling that you desire (or is dictated by the composer). However, this largely just requires mindfulness rather than learning a new skillset. The majority of what you've learned on the keyboard should cross over perfectly well.
The transition will not be too difficult if you have the desire and patience to put in the playing time. I own both the type keyboard you have been learning on and the type you aspire to transition to.
There is very definitely a different feel to the keys and the way they respond - both from a tactile (feel) sense and musically (the way the note sustains, how the volume reacts to the velocity of the key depression and release, etc.).
However the fingerings for chords and notes and hand positions will all be the same. So what you have learned to play so far will translate to the fully weighted hammer action keys. But you will need to spend some time playing to get used to the way the new keys feel and respond.
It's very similar to learning to type on a different computer keyboard. Recently I had to start using an external keyboard for my laptop after I spilled a drink on the keyboard and it quit working. All the letters are in the same place in relation to one another and the finger reaches are exactly the same. But the new keyboard has a distinctively different feel. At first it slowed down my typing. But the longer I use the new keyboard, the faster I get. It's just a matter of getting used to how much energy is required to press the keys.
So don't worry - you won't be starting over from ground zero or have to go through rigorous time consuming exercises. Just start playing it as much as you can and over time, you will get used to the difference in feel.
I am sure you will thoroughly enjoy expanding to a full 88 key keyboard. Hopefully you will also find some value in the ability to better control the dynamics of your music using the weighted hammer action piano style keys.
The weighted part just responds to your emotion. It's not like it changes the note or anything. If you feel strongly about a certain measure or measures just play it with more emphasis and the weighted keys will respond accordingly. You'll get it, don't worry. Just don't think about it so hard and it will come naturally to someone who has been playing for years like you. Some keyboards actually emulate weighted keys and play louder if you hit the keys harder. Maybe yours does that and you haven't noticed? Switching to weighted keys will improve your playing overall and give you a "piano player" feel. Like I said, don't worry so much about it, you will find it ease itself into your playing very naturally.