Pre-programmable single thread overseaming machine for attaching insoles. Machine is equipped with step motor driven front cup for differential feeding, which ensures the feed cup and front cup work to the millimmeter. In addition, the programming of the differential allows this versatile machine to build in 10 different steps of up to 50 % of fullness into the seam as required. Extra gathering can be done by the optional pneumatic gathering system. This system ensures always having even results of the Strobel contruction.