Merlin of Mines - Space Engineers

Control a Crane-Like Drill Arm With Mouse and Keyboard

Imagine you want to build a ground-based vehicle with a crane-arm for drilling, and we want to be able to have a cockpit for the crane that lets the engineer rotate it, raise and lower the arm, and extend it. Something like this:

Writing a script in EasyCommands to control the above is as easy as:

:main
set drillCockpit to "[DB] Drill Cockpit"
set rotationSensitivity to 0.25
async controlDrill

:controlDrill
set the "[DB] Drill Rotor" velocity to (rotationSensitivity * $drillCockpit right roll)
set the "[DB] Drill Middle Hinge" velocity to (rotationSensitivity * $drillCockpit downwards roll)
set the "[DB] Drill Bottom Piston" velocity to the $drillCockpit forwards input
set the "[DB] Drill Middle Pistons" velocity to the $drillCockpit clockwise roll
set the "[DB] Drill Front Hinge" velocity to the $drillCockpit upwards input
set the "[DB] Drill Front Piston" velocity to the $drillCockpit right input
replay

Let’s break down how this script works:

:main
set drillCockpit to "[DB] Drill Cockpit"
set rotationSensitivity to 0.25

First, we set up our main function. It doesn’t need to be called main - whatever the first function is will be considered the main one, and that’ll be invoked by default by the Programmable Block.

This main function sets a variable for the drill cockpit name, as we use that many times later, and then also sets a variable for the rotation sensitivity - this is just a multiplier so that our drill arm doesn’t move TOO fast.

async controlDrill

Then, the main function invokes controlDrill in its own thread. This allows controlDrill to do whatever it needs to do without blocking the main program.

:controlDrill
set the "[DB] Drill Rotor" velocity to (rotationSensitivity * $drillCockpit right roll)
set the "[DB] Drill Middle Hinge" velocity to (rotationSensitivity * $drillCockpit downwards roll)
set the "[DB] Drill Bottom Piston" velocity to the $drillCockpit forwards input
set the "[DB] Drill Middle Pistons" velocity to the $drillCockpit clockwise roll
set the "[DB] Drill Front Hinge" velocity to the $drillCockpit upwards input
set the "[DB] Drill Front Piston" velocity to the $drillCockpit right input
replay

The controlDrill function is constantly replaying itself, so its always (every tick) updating the velocity of our rotor, hinges, and pistons based on the user’s input. Note us using roll to indicate the camera (e.g. mouse, or arrow keys), and input to indicate movement (e.g. WASD). A rough breakdown of what this means specifically:

• right/left roll - left and right on arrow keys or mouse
• downwards/upwards roll - up and down on arrow keys or mouse
• clockwise roll - q and e
• forwards/backwards input - w and s movement keys
• upwards/downwards input - c and space movement keys
• right/left input - a and d movement keys

We can obviously mix and match these however we like!

Note that the choice of which direction we specify (e.g. forwards input vs. backwards input) tells us the sign of the velocity. e.g. forwards input would mean that when we press w, we’re increasinge velocity, and decreasing with s. If we specified backwards input, it’d behave in the reverse.

Enjoy your new drill arm!