I'm currently in the process of restoring a Sherwood DD-4030C. A problem now is the take up spindle sometimes would not rotate during playback and will give me a tape spaghetti nightmare. Here's how the take up spindle is constructed in this model: The white gear with a shaft goes through the center of the black gear, and the take up spindle cap is attached to the white shaft from the other side. The black gear is what would be engaged during normal playback, and the white gear would be engaged during FF/REW. There is a spring underneath the black gear which is supposed to be pushing it against the wool pad and make the white gear rotate with it. After some careful inspection, I get down to the conclusion that the problem is sometimes the white gear that the take up cap attached to is "slipping". Only the black gear is rotating during playback. What I couldn't understand for now is the purpose of this design. Using a wool pad as friction plate seems to be problem waiting to happen. If the white gear is supposed to be rotating together with the black gear, then why bother making them two different parts? Also, why wool pad? I don't think wool pad have enough friction and will tend to slipping, thus making the flutter worse. For now I couldn't come up with a solution to deal with this slipping problem, can I replace the wool pad with something more abrasive? ========================= One other thing I failed to understand is why the take up spindle cap needs a spring underneath it, apart from potentially popping the cap out.
I didn't read all your texts but I understand the situation kind of. Basically there are three kinds of take-up reel designs, for allowing the take-up reel to rotate at different speeds while everything else runs at a constant speed. The first option is a slipping belt that slips when The reel is going fast and or going slow and so the thing the part that goes out is the belt. The second option is a idler tire that wears out over time and provides the necessary torque for the take-up reel. The third option is a torque converter clutch using a spring and a cloth pad like what you have there and these can be taken apart and the cloth changed and or the spring pressure changed to increase the torque available to the take up reel. As far as how it actually works, everybody has a different way of doing it. The bottom line is that something has to give when the tape is at the very beginning of its life in a cassette. So the take-up reel is running very fast because the reel is small in diameter and when you get to the end of the tape, the take-up reel has to run slow because the reel in the cassette is now large and that's basically it. So something has to give in the take up real speed while everything else runs constant and whatever happened to yours I don't know but you need to put it back together and that's all I can explain for you.
Thanks a lot for the explanation, I did not thought about the mass of the tape reel could affect take up spindle and it has to slip on purpose. There are still many things for me to learn! I understood more about the problem today after some more fiddling. Basically the "retainer" that is supposed to hold the spring in place cracked and detached from the shaft, which makes: 1. The pressure on the wool pad not enough to rotate the shaft and take up spindle. 2. The retainer itself gets into contact with the chassis and creating unnecessary dragging. So I ended up 3D printing my own spring retainer and glued it tight with UV epoxy: Now the take up spindle is working correctly, and W&F lowered a bit more. To be honest I don't know how long my 3D printed part will hold before it fall apart due to the pressure from the spring, but at least I got to print more and repair it in the future when it starts to chew up tapes again. I'd be really upset if I were the one who bought this machine back then with its full price. There are so many important parts like this that are just not build to last and would crack and mess everything up one day.
I like your statement. ( Built to last ) How long is something like this supposed to last? Randomly car tires only last 10 years and you have to replace them. Likewise, the rubber parts in cassette players should only last about 10 years before you have to replace them and then the motors might last twice as long. But then you have to replace them and now you're talking about these little pieces. How long is a manufacturer going to stay in business? If parts that they make last forever then people don't buy more players? Just some thoughts.
Well, for rubber parts or motor I agree it will have wear and tear and needs to be replace or serviced after some usage. But cracking parts? No. Especially something that would end up in disaster if failed. (In this case, tape spaghetti.) You won't expect the rim or engine on your car to crack on you without you doing something really wrong in the first place. At least use some metal in places that is under high pressure like the spring retainer here, even using the cheapest metal would be better than using plastic here.
Agreed. But if the manufacturer is made things that lasted forever, would they stay in business forever? Because I would just buy it once and never have to buy it again LOL
This is a great conversation. I have noticed repeating problems with Panasonic (National) dual-tape mechanisms, specifically in the "clutch" mechanism where the retainer often splits and the spring-loaded remains of that part of the mechanism end up rattling around inside the case (except the metal spring, which gets attracted to the speaker!). I'm almost ashamed to say I have cannibalized perfectly good but "lesser" systems to reuse the retainers in my keepers. There's a different spring-based problem with Sharp "Twincam" mechanisms where a poor piece of design often fails - the very strong spring that assists the whole mech to engage is retained by a humble plastic post that is often found broken, thus not allowing the spring to do its job, and the so machine is effectively useless as a tape deck! My preferred fix is to find, or make from ss wire, a substitute spring with a longer tongue that can be bent around a more substantial part of the mech. It works but a PITA.
I've never had the post broken but I've had that little plastic washer that's supposed to hold everything together broke off and that's poorly made cheaply made.
Regarding the Sharp Twincam I think I have never seen another class of mechanism that has suffered so many times from damage from blunt instruments - which I presume is down to people trying to remove cassettes jammed in the bl**dy thing...
Yes I know all about these. Red sharp wq-t282 And the model with the spectrum analyzer in it WQ-t252 Both of these are for sale, if you're interested or for anybody else is interested.
I would love the red 282 but the cost of shipping out of Texas to the UK would involve a level of household expense discussion that I'm not prepared to initiate. Really sorry.
