This paper describes self-reconfigurable robot CHOBIE that adaptively construct a mechanical structure. CHOBIE modules have slide motion mechanisms and transform the structure by synchronous movements. First of all, mechanical features of the robots are described. Second, as an effective control method for the synchronous robotic system, a new scheme “temporary leader” is introduced. Some experimental results show the validity of the scheme. Third, scalability of the system is discussed. In particular, we focus on problems of synchronous of the modules and amount of data processing in the system composed of large number of modules.