Left dumbfounded trying to create a simple square platform.

[Dropbear67]

I spent hours last night trying to build a chassis for a rover out of girders and structural pieces. None of the "snap" points seem to make any sense. The structural pieces only have snap points on the end of them. It would be a simply dev change to put them on all three sides of the end so that we can easily do right angle snaps and make a rectangle. Something that should be so easy is so hard. Also trying to layer the flat square plates over the top of a structure like that is nearly impossible. It all seems to come from a lack of sensibly placed snap points.

I took apart one of the stock rovers in a sandbox to try and see how they have done it. One chasis has three long structural pieces side by side but they're not "snap" joined. They just seem to magically sit there.

I'd love to see some love given to this area of the game.

[Superfluous J]

Craft in KSP are in a tree structure. Every part is connected to one other part, until you trace back to the root part.

This means there is no such thing as an attached square made of 4 parts. It can look like a square, but one of the 4 vertexes will be not connected and when put under any stress (like say gravity) they will flex apart. You can (and we all do) get around this with struts, or with autostruts.

As far as mount points, you do not need to use them with many parts. When placing a part, if you put your mouse cursor on the side of the already placed part, most parts (including structural parts) will radially attach. Try it with say a fuel tank and a girder. Place the tank, then select the girder and put your mouse cursor (not the girder) against the tank. Then click.

Any more assistance will likely require a picture of what you're doing.

[Rocket In My Pocket]

This mod will address some of you issues with the nodes by adding more, I highly recommend it! But.. it's not going to fix the "tree" structure inherent in all KSP crafts as @5thHorseman described.

 

Edited June 30, 2019 by Rocket In My Pocket

[RealKerbal3x]

ReCoupler may help...

 

[Tweeker]

Snap them into the existing nodes, then rotate and offset them. 

 

[r4pt0r]

I dislike some of the build things too. Xenon tanks and the Micronode should have radial attachment enabled so I can slap them onto the sides of things without having to place a girder first.

[The Dressian Exploder]

57 minutes ago, r4pt0r said:

I dislike some of the build things too. Xenon tanks and the Micronode should have radial attachment enabled so I can slap them onto the sides of things without having to place a girder first.

That is so true!

[Tweeker]

And  you should be able to mount mystery goo in-line. 

You could build a nice little sounding rocket.