He had built nine humanoid robots so far, but all of them were demonstration models.
Literal
He [topic-は] until-now [at-に] 9 bodies [possessive-の] human-shaped robots [object-を] manufactured-[progressive-していた][but-が], that all [topic-は] demonstration models was.
人型ロボット 'humanoid robot.' ９体 uses the counter ~体 for bodies/humanoid figures. デモンストレーションモデル is a loanword compound. ~ていたが 'had been doing... but' sets up a contrast between quantity and purpose.