The shuttle block slides into position as the threading ring rotates during threading. It travels in a trackway and comes to rest in a locked position next to the full erase head. It is shown here looking from the back of the VCR towards the video drum. There are two guides, number four and five, mounted on the shuttle and both are adjustable. On the right is the number five roller guide. The height dictates the location of the tape as it enters the video drum. It is critical to the smooth and correct travel around the drum. It also has a tilt adjustment (not shown) that removes curl and keeps the tape flat. The most common roller problem is dirt and oxide build up. This must be removed by the cleaning process during refurbishing. This roller turns on miniature caged bearings inside so there usually isn't a surface wear problem. The bearings can wear out over time, noticeable by a clicking sound or roughness. This can sometimes show up in the picture as shaking or vibration. This failure requires replacement. The number four guide on the right is stationary but its hight is adjustable. It positions the tape on its way to the number five guide and it is constantly being polished by these surface of the tape as it moves by. It can develop a flat spot but the bigger problem is oxide build up at the bottom. This is the area where the tape exerts the most pressure when coming from the three and four guides. This must be cleaned away and the flat spot corrected during refurbishing. To keep the shuttle block held in position when threaded it is pressed against a metal boss under the threading trackway. To do this it is spring loaded using a torsion bar or push-rod assembly that fits between the ring and block. Click on the photo to examine this clever apparatus. To see the shuttle positioned in the unloaded (parked) position click on the picture. This is the cassette pocket where the shuttle and pinch roller reside before threading takes place. Everything is tucked away nicely inside this small area. In this position the shuttle rests under a plastic plate that protects it from the cassette lid should a mishap occur. Click again to remove see the components without the terms, arrows and plate. To see it in the in the Threaded position click here. To go back to the THREADING RING AND SHUTTLE BLOCK panel click here To examine the guide locations click here and to see the loading process click here (mpeg movie) ©Misterßetamax go to homepage