Nice!

can't wait to see how it turns out.

IK is not “Interactive Kinetics”, it is “Inverse Kinematics”. “Forward Kinematics” is when you use the joint angles and lengths to calculate the position of the end effector, “Inverse Kinematics” is the opposite where you take the required position of the end effector and use that to calculate the required joint angles.

You also need to be careful with those breadboards. Breadboards are made for low voltage and low current uses, not for things like stepper motor drivers. Breadboards have a low current rating (apparently 500 mA to 1 A but that depends heavily on breadboard and wire quality) and I would recommend not going anywhere near that limit. If you just have a bad connection or run the current too high for too long it can melt the board and that can lead to more things getting shorted as the metal strips are only separated by plastic. Breadboards just aren’t made for running motors on them. They also have a lot of capacitance and inductance compared to other options. I would suggest you buy yourself some strip or perf board and use that instead. Another option is to buy an arduino CNC shield, you don’t need to use it with an arduino and it breaks out the step and direction pins so you can just connect those to your driver board but it has adequately sized traces for the power supply and has a fuse. You could use multiple of the CNC shields with no issues if you need more than four stepper motor drivers. Or you could just buy a 3D printer mainboard and connect that through USB or serial or write your own firmware for it.