  Force control enables hands-on teaching and physical collaboration, with the
potential to improve ergonomics and flexibility of automation. Established
methods for the design of compliance, impedance control, and \rev{collision
response} can achieve free-space stability and acceptable peak contact force on
lightweight, lower payload robots. Scaling collaboration to higher payloads can
allow new applications, but introduces challenges due to the more significant
payload dynamics and the use of higher-payload industrial robots.
  To achieve high-payload manual guidance with contact, this paper proposes and
validates new mechatronic design methods: standard admittance control is
extended with damping feedback, compliant structures are integrated to the
environment, and a contact response method which allows continuous admittance
control is proposed. These methods are compared with respect to free-space
stability, contact stability, and peak contact force. The resulting methods are
then applied to realize two contact-rich tasks on a 16 kg payload (peg in hole
and slot assembly) and free-space co-manipulation of a 50 kg payload.
