Sandbox Tubes

This is a very difficult geomerge!

One way I would suggest is (while not host) place a y-intersept, or other tube, on the ground. Go in the tube, look down, and begin rapidly pressing A. Within a couple clicks the tube will sink into the ground.
Notice: This method has only been proven to work on the SandBox Main Layer

Another method would be to brace with, literally, every tele node and weapon holder you can, and use walls or blocks as foundry doors. Just set the tube to not spawn and interlock the tube and block/wall.

Best of Luck
FSC RedNeck

 

if you are trying to do this in the crypt, turn the tunnel upsidown. if the teardrop goes outside the crypt, the item will delete itself.

 

If you want to try a proven method, just make sure you understand that the geo-tap method will not produce consistent results and will sometimes tilt the tube a good deal. What I do whenever I need to accomplish this particular merge is to simply interlock a wall into the top of the tube like this: __ Then, simply brace the hell out of it and geomerge it as you would any other object on Sandbox. You may have to try a few times to get it, but the end result should be what you are looking for.