How to use Weld

[c-sanchez]

I'm trying weld a object in the face of other, But I do not understand how you should do.

So I see the Weld option appears only when an entire object is selected in body selection mode.

I would like to know how to merge the object A with the object B

Using the selected faces.

[micheus]

Weld is used to merge the objects, but they need to be close each other. In most cases we let they touching each other, once the regular command [LMB] uses a very short distance as tolerance. In some cases we can use [RMB] and set this value. This value will be related to the distance between the correlative vertices (the greater).

When the objects are far away as you are showing us one option would be to use Bridge - if there is no problem to create a new "segment" between the two objects. In this case, the action is made by selecting the two opposite faces (as you showed in the picture) and applying the Bridge command.

What is important remember for both cases is that these commands requires the two faces have the same number of vertices/edges.

[oort]

c-sanchez,
You can also use the Put On command in Face mode to make sure the two blocks are touching before using Weld.

oort

[micheus]

Oh!, good tip oort.
I assumed he wouldn't like to move the pieces.

[c-sanchez]

Yeah, Put On and Bridge are the better options for this.
The result with Weld is weird.
Choose Face 1

Choose Face 2

Put On

Weld

[micheus]

For Weld, did you use Out On before?