Design is very good. The Manufacturing process lacks the quality that was put in the design. Parts that slide together do not have any starting taper for easy assembly. Lot of burrs on every cut or hole. I had to rework the bearing end of the roller because the shaft was rubbing on the plastic insert and would not turn freely (the plastic mold is in need of maintenanc, the OD wobbles in the mating part and there is not enough clearance for the shaft on the ID) Instructions are written by someone that English is not their native language and it showed. Instructions were printed in such low resolution and small print it was very difficult to follow. Pictures or drawings were also in low resolution therefore details were not distinguished. If you wish to see execelent instructions, visit some old “Heath kit” instructions. They were crystal clear in their days. Time will tell if the product will last. Overall I am happy with the product so far. Part quality in this day and age seems to only have lip service. Everyone sings the tune, but can’t walk the walk. So my expectations are low to begin with.