Compound Gear Train

digraph gt {
  rankdir=LR;
  graph [bgcolor=transparent];
  node [shape=circle, style=filled, fontname=Inter, fontsize=10, fixedsize=true];

  M [label="Motor\n1500 rpm", fillcolor="#dbeafe", width=1.1];
  G1 [label="G1 z=20", fillcolor="#fef3c7", width=0.8];
  G2 [label="G2 z=60", fillcolor="#fef3c7", width=1.2];
  G3 [label="G3 z=18", fillcolor="#fef3c7", width=0.7];
  G4 [label="G4 z=72", fillcolor="#fef3c7", width=1.4];
  O [label="Output\n93.75 rpm", fillcolor="#dcfce7", width=1.1];

  M -> G1 -> G2 [label="3:1"];
  G2 -> G3 [style=dashed, label="same shaft"];
  G3 -> G4 [label="4:1"];
  G4 -> O [style=dashed, label="same shaft"];
}