The cutter is sturdy and appears to be very well constructed. I tested it when it arrived and it cuts square and straight whether cutting 1 sheet or many. Part of the key to getting straight and square cuts is to use the pressing bar which clamps down on the paper when the pressing handle is rotated clockwise to lower the pressing bar tightly onto the paper. The instructions are minimal and are not very good translations to English. The "Plastic File" is the long plastic bar in a slot below the blade and is contacted by the blade to complete a cut. Mine is red and it had some reddish oily substance on it which I wiped off with a paper towel; also wiped the slot that holds the bar. The bar is held in place with two plastic thumbscrews in the side of the bar slot and visible from the underside. This bar is what is referred to in the instructions: 2 "Please take out the file circumvolution 90 degree......" The bar can be swapped end for end and rotated on its long axis to get the 8 directions mentioned in (2). There is a clear plastic guard on top of the cutting mechanism assembly which I removed....common sense says keep fingers out of the cutting area when operating the cutter handle. I took a few minutes to tighten the screws holding the blade in place as well as the various nuts and bolts visible from the underside. It is probably a more heavy duty tool than I really need, but I like it and will pass it on to my son when I no longer have need to use it.