Automatic Envelope Address Robotic to make it look human

I sign dozens of personal letters every week and would like that entire step to happen without me hovering over the page. The goal is a compact desktop robot that grips a normal pencil and reproduces my handwritten signature in a mixed cursive/print style. Once I supply the signature file, the unit should run fully on pre-programmed actions—no voice control or remote steering—so I can drop a letter onto the platform, press a single button, and watch it sign.

What I need from you
• Mechanical design for the pen-holding arm and paper positioning system (servo or stepper driven is fine, as long as it is precise and gentle on the paper).
• Embedded control code that reads a stored path and executes it smoothly at natural writing speed. I am comfortable with common maker-grade hardware such as Arduino, ESP32 or Raspberry Pi, so feel free to choose whichever fits best.
• A straightforward way for me to upload or replace signature paths in the future (e.g., simple USB transfer or SD card).
• A short demonstration video or live test confirming the robot can sign at least three A4 sheets with an ordinary HB pencil without tearing or smudging.

Acceptance criteria
– Signature stroke matches my mixed cursive/print sample within a 1 mm tolerance.
– Consistent line weight comparable to a human hand using light pressure.
– Cycle time under 15 seconds per letter.
– All project files delivered: CAD, gerbers/STLs, firmware source and a basic usage guide.

If this sounds like a challenge you can bring to life, let’s talk parts selection, timeline and milestones so I can start sending perfectly “hand-signed” letters on schedule.