What the Dragon A400 Prepares Before Assembly
A tube cutter does the work that used to happen at the bench: shaped ends, holes and marks, so the assembly starts from parts that fit.
Tube and pipe assemblies used to begin with a saw and a grinder. The machine that replaced that work does more than cut square, and understanding what it prepares explains why the assembly stage goes differently.
It shapes the end
The plasma torch on the Dragon A400 cuts to a programmed shape rather than a straight end. Saddle cuts, cope joints, holes and notches come off the same program, so the shape of a joint is defined before the pieces reach the bench.
The practical result is a gap that is controlled. A saddle cut produced from the drawing on every piece means the tenth frame closes the way the first one did, instead of being fitted individually.
It puts features in the same pass
Holes and notches are cut in the same program as the end preparation. Bracket holes land where the drawing puts them relative to the end of the tube, rather than being marked by hand from that end. On a run, that positional relationship repeats without anyone measuring it again.
It marks the piece
The head carries a pneumatic engraver and a marker, so assembly marks can be applied as the part is cut. Member numbers, orientation and match marks are the difference between assembling a frame and solving it.
It is a cutting machine
Three things it does not do are worth stating plainly. It does not bend, so every bend in a tube component is a separate operation. It is not a tube laser, and it cuts by plasma, which suits the wall thicknesses and joint shapes tube work needs. It does not weld, so the shaped pieces still become the assembly in a separate step.
What goes to the welder
Cut tube with shaped ends, holes in position and marks on the piece. Fixturing, weld sequence and joint type belong to the assembly step, and where a joint repeats on every piece the cobot cell can follow a programmed path rather than a hand lead.
What to send for it to work
Profile sizes and wall thickness per member, cut lengths, the joint each end makes, hole positions referenced to a face, and quantity per member. Preparing tube components for a welded frame lays that package out in order.