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Constant pressure is exerted upon the pinch roller assembly when the tape is moving and this will deteriorate its rubber over time. In the photo above it is easy to see the difference between the rubber of the new one on the left and rubber of the worn, glazed hardened one on the right. The pinch roller is considered to be a consumable item, because it will eventually wear out and reguire replacment. If the rubber is still soft and it only has tape deposit built up, it can usually be renewed by removing the assembly and rolling the rubber at an 45 degree angle across a rough sheet of 80 grit sandpaper, then cleaning it with special solvent. This reguvenates the surface. It has a small caged bearing inside and sometimes it will fail, causing the picture to shake in a erratic manner. This bearing can be tested by removing the roller assembly and rolling it across a hard flat surface, if it is bad it will chatter or run rough. Click on the picture above and you will see that small bearing in the exploded photo in the upper left. The dime is to give you a size perspective. In the main picture the pinch roller assembly is shown mounted on its geared slider. The toothed cresent is what moves it in and out of postion when it is driven by the threading motor transmission. Notice also that the slider assembly has the number nine guide roller mounted on it (right of pinch assembly). It is very similar to the number five guide on the shuttle block. It has the job of drawing the tape out of the cassette during the loading proceedure, in conjunction with the number five guide on the shuttle block (not shown). It also guides the tape back into the cassette. When not in the loaded position the slider and roller sits parked next to the shuttle assembly. After a cassette is inserted and the electronics "knows" that it is down and properly seated the assembly travels out of a triangular pocket located in the cassette shell and draws the tape out along with it. The slide assembly is positioned under pressure against a wedging block near the motor. The tension spring in the slider assembly supplies the required holding pressure. To better picture this, click here. To close this panel and go back to the main page click here   ©Misterßetamax go to homepage |