Ftyjtk

So say a bank robber walks into a bank and hands the teller a note saying simply "please give me $1,000" (or maybe even just verbally saying "I need $1,000 please") and if the teller accepts, which they probably would because they're supposed to comply with the robber, he takes the the money, otherwise if they refuse, he leaves.

How is this different than say people asking for charity donations in the street? He just politely requested money without making any threats.

As a concrete example, consider Missouri v. Coleman, where Coleman handed a teller a plastic bag and said "I need you to do me a favor. Put the money in this bag", and later as the manager approached, said "Ma'am, stop where you are and don't move any farther". Coleman was convicted of second degree robbery: but the appeals court found that he had not acted foribly, so his conviction was overturned. Instead, the court entered a conviction for the lesser offense of stealing which is when one

Appropriates property or services of another with the purpose to
deprive him or her thereof, either without his or her consent or by
means of deceit or coercion

The act may also be termed "theft", as in Washington state. The thief is acting deceptively and thereby gaining control over property.

Generally, the law would not just look at the robber's literal words, but at how a reasonable person would understand them in context. And it will assume that the robber meant them to be understood in that way. Here, a reasonable person would understand such a note to be a threat of violence, so the law will assume the robber meant it as a threat.

Likewise, a mob boss who tells his associates to "take Joe for a ride" will not be able to avoid prosecution by insisting that he only told them to provide him with a pleasant sightseeing tour.

How is this different than say people asking for charity donations in
the street?

Context is everything.

Obviously, someone asking for charity donations on the street will present themselves as a legal charity, like the Salvation Army, etc. If you meant "charity" in the sense of someone panhandling Panhandling | (Merriam-Webster), most if not all people will take the asking for $1000 as an absurd request and keep walking. It's possible that someone may take offense and the police may deem it an attempt at mugging or stealing, depending on jurisdiction, and see user6726's answer.

But to walk into a bank and ask for $1000, the context is completely different. That's because a bank is where the money is. You don't usually walk into a bank for anything other than a financial transaction, either a legal or an attempted illegal transaction. As the (apocryphal) saying goes, Willie Sutton (Wikipedia) robbed banks "Because that's where the money is".

So while it's possible that a polite bank robber trying to not be aggressive may get away with robbery under a lesser charge, anyone in a bank requesting an illegal withdrawal - by any means - is still a bank robber, and 99% of the time, a jury and judge will see that.

You can't have it both ways. Either the person used words that cause the teller to fear that violence will occur if the money isn't given or they didn't. If the former, it's a threat. If the latter, the teller won't give them the money.

If their words caused the teller to give them money because the teller feared violence, and this was the intended result of their words and not totally unexpected, that's the definition of using a threat of force to obtain a thing of value.

The lack of use of force means, of course, that it's not a violent robbery. But if the teller feels threatened, it's a threat. If the teller doesn't, they won't give the person the money.

Robbery is theft carried out through force or the threat of force. The most important part of your hypothetical is that you're saying the person asks for money without making a threat (and presumably without force).

If that is the case, the person is not a robber and the transaction is not a robbery. It is, like you said, the equivalent of a request for a charitable donation, and it is legal.