What is the difference between 端, 縁 and 先っちょ?

Question

I struggle to visualise the differences between 端, 縁 and 先っちょ after reading many examples and definitions online:

The approximate english translations are very similar:

端: end, tip, point margin (synonyms: 端っこ)

縁: rim, brim, edge brink

先っちょ: end, tip, point (synonyms: 先、先端)

I don't understand the difference between these sentences (some might be incorrect)

1. がけ端 vs. がけの縁 vs. がけの先っちょ

2. ベッドの端 vs. ベッドの縁 vs. ベッドの先っちょ

3. 鉛筆の端 vs. 鉛筆の縁 vs. 鉛筆の先っちょ

Another word I found is 際, but I'm guessing this is rarely used.

Probably a related post:

縁＆端: Are these readings still relevant?

I would like to know the contexts and when it's appropriate to use each word.

Answer 1

I think 縁＆端: Are these readings still relevant? 's best answer is a good explanation.
I added a diagram because you said it was hard to understand the nuances.
My response is more about the nuances of actual use than an explanation of regular grammar.

「端」 simply refers to the end, it is used in conjunction with 「先」 to indicate the 「先端」.
In this case, 「先」 and 「端」 are synonymous.
(When combined with 「末」 it means 「末端」 -> 「末」 and 「端」 are synonymous ,etc.)

The red part represents the "先" and "端".
The green part represents the "縁".

In the dictionary, 「端」 and 「縁」 are almost synonymous, but in common usage, the above nuance is used with more awareness.

example

• 端 : It refers to both the end of object.

  • 紐の端
  • テーブルの端
  • 箱の端はざらついています。
  • 街の端には郵便局があります。

• 縁 : It is the brim or rim. You can think of it as the unsharp end of an object.

  • 椀の縁
  • 窓の縁
  • 窓の縁に雪が積もっています。
  • 濡れたグラスの縁をなぞると音がしました。

• 先 : It is the part of the tip from your point of view.

  • 指の先（指の先っちょ）
  • 棒の先（棒の先っちょ）
  • ペンの先が刺さりました。
  • 先の方に何か見えます。