Philip Rahm International

How to Change or Adjust a Fischbein Rotary Knife

A Fischbein rotary knife is an essential piece in the brand’s entire automated bag closing sewing machines. Once the bag is stitched up, the blade makes a quick, clean cut that separates the stitched thread from the rest of the thread loaded in the machine. The blade has to make many cuts every minute, so proper mounting and maintenance is necessary for producing consistent performance. It may be necessary to exchange the cutting edge periodically for different applications. Whenever this is required, there are few easy steps to follow when mounting the new blade to ensure that it works the way it is supposed to.
 
The company’s 100, 101, 200 and 201 bag closing equipment models are all compatible with one of three blades.The thread pusher extension kit includes a Guillotine style cutter (also called a shear blade) that operates using an air powered pneumatic cylinder. The clipper or scissor blade is another option and is ideal for applications where crepe tape will be used. With a powerful set of jaws, this blade effortlessly cuts through thread and tape in one fluid motion. The Fischbein rotary knife is the third option and operates with a swinging blade powered by a pneumatic drive. During operation, the blade swings through and slices off the run of thread before any excess can be threaded from the machine.
 
The swinging blade is held on with a stationary panel that is screwed onto the machine.Before the blade can be changed out or adjusted, the sewing head will need to be removed from the machine so that the operator can access the panel. A few metric screws hold the panel on and can be removed fairly easily. Once it is removed, a new blade can be slid into the device. Before putting the machine back together and switching it on, though, it is best to adjust the panel slightly to provide the perfect cut angle.
 
It may seem natural to keep the panel parallel to the swinging action of the Fischbein rotary knife, but this will produce a suboptimal cut. Instead, the panel should be set at a slight compound angle next to the blade.The blade should be set closer to the top of the panel by a single degree or a little less, and the cutting edge of the panel should be set in a half degree or so closer than the ready edge. When done right, the blade should meet a tiny bit of resistance as it swings into the cutting position. This can be verified by manually pushing the blade back and forth through the cutting area, which should be slightly difficult to do. This setup will help the blade shear off the thread more easily than a parallel cut.
 
Once the panel and blade are in their desired positions, the sewing head can be reattached to the machine and the device put back into operation.If the panel is set correctly, it should be clear once the blade starts producing more precise cuts.