Box2D: how do I make one body passively attached to another?

Question

I'm trying to use joints in Box2D to have one body passively attached to another. For example:

[B][A]

Goal: When A attaches to B, B is always to the left of A. Other bodies should still collide with both B and A but I don't want B to have any physical effect on A. B shouldn't "weigh down" A.

Problem: B always "weighs down" A.

I've tried multiple joints. I've tried setting B's mass to zero. I've tried setting B to ignore gravity.

How do I make this work?

Answer 1

OK, I'm dumb.

Setting the Mass to 0 defaults the setting to 1.

Set the Mass to 0.001 worked.