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Talk about ugly. This could certainly spoil your day. What you are looking at here is a friction tab from inside a video cassette. It is destroyed so you can't see how it is made or what it does and what happens when it comes loose. But it is getting more important because I am seeing more repairs related to these friction tabs. These problem tabs are located at each of the cassette openings. Their job is to keep the tape from spilling out from inside the cassette during normal handling. They gently press against the tape as it lays next to a pin. It has a surface that is design specifically for this The one above has come loose from inside an older cassette and made it's way to the video drum. (The upper part of the drum has been removed here for a clearer view.) The spinning video head on that round disk was going thirty revolutions per second when it slammed into that loose tab. What's left of it is that black slab sticking out from the demolished head chip. Head disk replacement is over a hundred dollars, higher end units can be expensive, and some are no longer available. While it's not always the common outcome it certainly makes you want to pay attention to the possible risk from using older cassettes. Click on the photo. Here is the culprit up close. In the upper left corner of this photo is a tab that was removed after becoming loose and getting wound around a capstan. In the upper right hand corner is a tab that stuck to the back side of the video tape and somehow made it all the way through and back into the cassette. It is extremely fortunate if this is where it ends up. That would mean that it traveled all the way through the tape path without getting stuck to or lodged against something. Maybe it got attached during winding. Here you can see the textured surface that touched the tape. Look in the center of the photo and you'll see a tape that has been removed so you can look through the left side window and see the tab mounted inside. You can also see that the adhesive has degraded, become bubbly and is coming loose. How do you know if your older cassettes have this potential danger? And what can you do about it? In this article we are going to look at several ways to attack this potential problem. Click on the photo and you will see an illustration of the tape path inside your Beta (Sony late design is shown but others are similar). The tape path is shown in red. The guides are numbered in the order that the tape moves during record and playback. Once a tab comes loose from inside a cassette it can end up anywhere in this path but most show up stuck to the tension arm (number one guide) shown in the lower left corner. This is because the supply side tab is usually the one that falls off while the tape is moving forward. Count your blessings if it stops there. If it moves further things get harry. Click the photo and check out the actual components. Follow the numbered arrows as we look at the places these tabs can end up. Arrow #1 is the number one guide and tension arm. Arrow #2 is the number two guide and arrow #3 is guide three. Arrow #4 is guide number five which is a roller mounted on the tape shuttle. Arrow #5 is the full erase head and arrow #6 is the number six guide. Between the full erase and the number six is the impedance roller. Not a Betas have this. Arrow #7 is pointing to the open area in the video drum where the video heads travel. Arrow #8 is the number seven guide and #9 points to the ACE assembly. Arrow #10 is the number eight guide and #11 is the capstan and pinch roller. Not easily seen because it's hidden behind the roller is the number nine guide which is a roller similar to the one mounted on the shuttle. Last in the line up is arrow #12 which is pointing to the last guide, number nine. Click the photo and the arrows disappear. Click it again the various locations are shown without a tape threaded and without the upper part of the video drum, which is removed. There is only one way to prevent this from happening, and it isn't easy. You have to inspect all your older cassettes. The method is pretty painless but first it's a good idea to familiarize yourself with the construction of the Beta cassette. If your ready to take on this task click the photo. Look at the exploded diagram and take note of these parts. The top, bottom, lid, the two reels and the four screws are the operative parts for now. Next take a suspected cassette and turn it bottom up. Click on the photo. Remove the four screws from the four holes illustrated and set them aside for later. Click the photo.
Using a pointed object, press the locking tab inward to release the lid (it is shown in the cutout on the left). While holding the cassette with the bottom facing down ass illustrated lift the top off the cassette. If your tapes have spine labels on them you can still do this but you will want to lift it up in a hinge-like motion (as shown above). Swing the top completely over or remove it and set it aside. As noted in the photo is it best to open the cassette with the beginning foil leader located across the front (tape fully rewound). This will prevent damage to the tape. Click the photo. Remove the two reels and set them aside in a safe place. Examine the cassette bottom half and locate the two tabs (shown by the white arrows). Click the photo. Here is a close up of both tabs and the glue is giving up. Click photo. Take your thumb and fore finger and press both tabs back down against the inner shell. This will push the tab back against the glue and make it hold for now. You now have a decision to make. Are you going to keep these cassettes or just try to make it through a recording session and then discard them? (You may want to examine the first question in the "Ask MisterBetamax" section before throwing your cassettes away.) If all you want to do is to temporarily prevent the tabs from coming off then you can skip forward to the part on putting the cassette back together. If you want to permanently repair the friction tabs then click on the photo for the next step. We are now going to glue the tabs to the cassette shell. There are several ways to do this. You can use super glue or a plastic filler material, but the least messy and easiest way is to use a two part epoxy paste. Shown in this photo is the type of epoxy that is easy to handle and commonly found at your local hardware store or auto parts place. It might be called a leak repair or radiator fixing compound. It is pre-measured and packaged in rolls the size of wrapped coins. All you have to do is slice off a thin section then cut that slice into small manageable wedges. Be sure to follow the instructions of the manufacturer and knead or mix it into a uniform color before applying. Click the photo. Next press the paste over the tab and covering the hole if it has one. Work it in a little and be sure it sticks to both tab and plastic. Some tabs don't have holes cut in them and with those just make sure the epoxy is on both the edge of the tab and the plastic. It doesn't take much to hold these tabs on, so easy does it. Too much and the mound of paste (chemical name is resin) will get in the way of the cassette reels. Also keep in mind that once the material is mixed you're going to have a limited amount of time to get your repair done, another reason for only mixing a small amount. Click the photo. Here you see a finished repair. Don't worry about appearance or getting tremendous adhesion. Once again it doesn't take much strength to keep these tabs securely in place. Click the photo. After a few minutes the epoxy has hardened and your ready to assemble the cassette. Place the reels back into the bottom half and turn one of them to remove any tape slack (smooth and flat from pin to pin is what you want). Click the photo. Now swing or place the top back onto the bottom making sure that the flip up lid stays in the down position like when it is closed. Press the assembly together so that it is uniform and the tape is flat. Click the photo. Holding the cassette together turn it over and set it down with the bottom up. Check to make sure that the tape is located as shown as shown in the photo. No buckles or wrinkles and between the standoff and the lid. Install the four screws and your done. Click the photo. The left side of this photo shows the repair for a tab with no holes.
On the right is the later design tabs where the problem has been eliminated by a redesign. It now is captured inside a cavity. Click the photo. At this point you may have several questions so let me try to answer them for you. This photo shows why the tabs are needed. They prevent spillage and keeps the tape flat across the front at times when the tape inside might actually be loose inside the cassette. The situation above is worse than normal. (If the tape were to spill out or billow in the front it could cause a miss-load and result in damage to the tape or the VCR.) Click the picture. How do you wind a tape forward so you can look through the inspection window and see the tabs without fast forwarding your Beta and putting it at risk? The answer is to use a tape winder, this will eliminate dragging a tab through you machine. You'll need one that has fast forward and won't damage your tapes. This gives me a prime opportunity to shamelessly promote buying a winder from me, seen here on the left. Another option would be to use a Sanyo Beta VCR as your winder. Their VCRs don't thread the tape into the path during rewind and fast forward. How do they do this and where does the tape go? Click the photo to see how the tape travels inside a Sanyo during winding. This completes our discussion, but there is one last thing. If you pop out a spring or a piece falls out during your repair operation and you need to know where it goes, you can click on the picture again. Here are all the parts identified and in the right place. Click the photo again and the arrows and words will go away. Did VHS have this same problem early on? You betcha. There is an alternative way to overcoming this loose the tab delimma. To see another option click here. |