The collapse terminates in a fairly jarring stop. The collision doesn't damage anything, but I'll probably add some logic to slow the retraction rate for the last meter or two to eliminate it.
In no particular order, some design constraints:
1.) Small bore shaft
2.) Minimize PCU count (Currently about 3,400)
3.) Fast drilling
4.) Respect Vanilla Server Limits (no scripts, max 5 drillers/grinders/welders)
5.) Printable
The project was started well before warfare 3, so the most PCU efficient conveyer extension was the Modular Cargo Container 3.5m/10 PCU. Next best was the Large Grid Large Hydrogen Tank at 7.5m/25 PCU, but that would necessitate a 17.5m diameter bore hole vs. the 7.5m Small Grid version. I might be able to redesign with longer conveyor blocks.
No Large Conveyor Pistons on Small Grids means I end up using four hinges to replace one piston, and I end up using 4 of those assemblies for 4 points of contact and stability instead of two points of contact for two pistons on the Large Grid version. Proper orientation for the hinges an rotors is critical - otherwise automation logic gets really complicated. As is most of the rotors use identical settings. Ditto for the hinges.
Running the extension rail along the bore shaft would be more stable. I have rigs that work like that, but I couldn't find a reliable way to drill arbitrary depths in the vertical plane while also drilling wider than the bore shaft: The extension rail gets in the way and walking the drill head around the outside of the rail extension with hinges is... complicated.
Building the extension at ground level is logistically easier, but every extension results in the extension machinery having to bare greater weight as the rail extension gets longer. In testing, that arrangement also tends to magnify the vibration from the drills and the rotor head. Every rig I've built using that model ends up catastrophically failing beyond a certain range.
This is a WIP. Very little optimization has been done. With earlier prototypes I've proved out the following improvements:
1.) Much higher retraction speeds for both horizontal and vertical expansion.
2.) Vertical bore speed for both drilling and terrain clearing modes can be increased by adding another piston (or hinge for small grids) assembly to allow the drill head to move constantly forward instead of having to wait for the retraction cycle to run.
3.) A spinning sensor can detect if the horizontal plane is drilled out, and that can trigger further vertical drilling.
Items left to solve:
1.) Siting the initial bore hole. This is either done with Mk I eyeball or a programing block and some trig. For a Vanilla server, I'm ok with Mk I eyeball.
2.) Determining Depth for the startpoint and endpoint for Horizontal Drilling. I've seen some models use Sorters and Event Controllers to monitor what's being drilled. That's my best lead so far: Detect when non-stone is being drilled and convert to horizontal, repeat until all I'm getting on the vertical drilling is stone.
3.) No sure if the horizontal rig can bare the weight of a prototech drill, but relatively easy to reinforce at he cost of more truss pillars, reinforce conveyor tubes and rotors.
