christiandaelemans
Active member
nvm….. undid a connection and put another one in the wrong place. put it all back together, worked better than most times for a moment, now it’s just like how it was to begin with. has the pitch pot gone bad?
cjacek
Analogue Enthusiast
Yeah, to tell you the truth, without looking at the unit closely, it'd be hard to diagnose something like this. It might be something simple which was overlooked or something much more complex. Hard to say as it is.
christiandaelemans
Active member
christiandaelemans
Active member
could this be a problem with the pinch roller? only rubber component i haven’t replaced.
cjacek
Analogue Enthusiast
The pinch roller definitely looks to be slipping and will cause speed fluctuations. I'm not sure if this will fix all your problems but it should stabilise the tape speed if the rubber (of the roller) is not slick but rather grips well. Try this first: examine visually and with your finger if the rubber on the roller is hard or sticky. If it's hard, try to dip a piece of cotton pad or lint free cloth in some 99% alcohol (squeeze the excess out so that it doesn't drip) and clean the rubber on the pinch roller. You want to be seeing black residue on the pad or cloth. Do this several times. This will expose new rubber on the rubber roller and should grip a lot better (but don't do this if the roller is sticky already and falling apart). Touch the rubber - it should become more "grippy" as you clean). Then you want to also very carefully and thoroughly (using maybe a cotton q-tip and alcohol or even piece of cotton pad or cloth), clean the chrome capstan shaft until it shines (looks dirty). This should (at least temporarily) give the pinch roller some service life and give you an idea if it work better, as far as the speed is concerned. Record some new content to test how it plays back. My hunch says it will be better or perhaps fixed.
cjacek
Analogue Enthusiast
.... and that plastic thrust adjustment screw I mentioned earlier, just make sure the large capstan fly wheel spins easily and also has a tiny bit of "give" up and down, cause if it is too tight, it might strain the motor.
cjacek
Analogue Enthusiast
.. but do the roller rubber and shaft cleaning first, as I suggested earlier.
christiandaelemans
Active member
yeah, the pinch roller is very smooth and has little to no grip when i touch it. is it supposed to be slightly sticky? also, i don’t have 99% alcohol (i should probably get some since i’m now in analog world lol), but when i get some and want to clean it, how do you suggest i get inside there? i’m unsure how to take off those 2 odd looking screws that hide the heads, but i’m guessing that would be the best place to get in there from. thank you for giving me some hope that i haven’t had in a month!!! can’t believe i’m going to actually get this guy alive again.
cjacek
Analogue Enthusiast
Ah yes those two damn strange screws. There was a special tool for it but I recall once I just used two pointy wooden kebab sticks (no joke) to kind of insert one and the other (into those two tiny holes of each screw) and I basically unscrewed each one. Took some time but I manged it. I used wooden sticks because I had them and they wouldn't scratch anything. But honestly you can just use anything. You basically want to get something in there to unscrew those things and gain access to the head / pinch roller area for easier cleaning. As far as the pinch roller, from your description, looks like it can benefit from the cleaning treatment I mentioned. The thing with pinch roller rubber at that time of manufacture was that some of the rubber disintegrated over time, into a gooey mess (sticky) and some of the other rubber didn't fall apart but rather turned hard. It had to do with the curing process at the time I guess. Point is that if yours is the way you describe (smooth, no grip, rather hard) then you're lucky in this regard. Lucky because you can actually restore it without replacing it, at least for now. There is usually stuff specially made for rubber restoration, strong stuff but in your case I think it could be easier, faster and maybe safer (at least for testing purposes) to get some alcohol (denatured alcohol is fine too) at a local store (but NOT rubbing alcohol, it has too much water). It should recondition the rubber on that roller when properly done, by removing the top slick layers.
cjacek
Analogue Enthusiast
... or maybe try really sticky adhesive tape on those screws and turn it. Haven't tried that myself but could work too.
cjacek
Analogue Enthusiast
... shouldn't be sticky but rather "grippy" after ward (the rubber roller I mean, after cleaning).
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cjacek
Analogue Enthusiast
..the whole point being to remove some of the slick / smooth layers up top the rubber (to expose good rubber down below) and the alcohol will do that along with some careful scrubbing.
cjacek
Analogue Enthusiast
..also when cleaning the roller, do so manually, turning the roller with one hand while cleaning with the other, ideally in the direction the tape travels, to get equal removal of the top rubber layers and have control. And of course the capstan shaft.
cjacek
Analogue Enthusiast
... and while you're at it, also the two heads, carefully with a q-tip and alcohol, in the direction of tape travel.
sweetbeats
Reel deep thoughts...
The pinch roller is technically called the capstan idler. It doesn’t drive anything. The capstan shaft is what drives tape in PLAY mode. The pinch roller, if slick or hardened, needs to be replaced. Making the surface more rubbery or “grippy” may temporarily help, but if the rubber is hardened it is hardened all the way through. And the roller doesn’t work by gripping the tape…because it’s not a driven roller. It’s a passive idler. It works by pressing the tape against the capstan shaft and when the rubber is in a serviceable state it deforms around the capstan shaft which wraps the tape around part of the circumference of the capstan shaft. This creates enough of a contact area and high enough friction coefficient for the metal capstan shaft to grip the tape and move it. The roller should not be hard or slick, nor should it be tacky. It should feel like…rubber. The capstan shaft should spin freely. When you had the belt off did it rotate freely? Like you spin the flywheel and it keeps spinning for a bit? Are you sure you have the right belt?
Honestly it’s so hard to tell what all might be happening, and it makes me nervous to get that engaged because you shared you had something connected incorrectly. There’s no telling what that connector does or if you may have damaged something by having it hooked up wrong. There is nothing safe about being hasty when working on something like a 244 or similar.
Maybe your motor drive circuit is failing. When the capstan motor is spinning can you grab the pulley and make its stop? Like does it feel weak or does it spin strong and it’s a fight to make it stop? It should be the latter. And if it spins too slow even when it’s not under load then there is likely some problem higher up with the DC servo that drives the capstan motor.
You can ask questions like “is it this?” Or “is it that?” But realistically understand we have no way to know. You’re not presenting a common problem, and none of us have the machine in front of us on a workbench with equipment to diagnose one what’s going on. I’d start with answering cjacek’s questions about the capstan thrust adjustment, and also get yourself a copy of the service manual. Next I’d replace the pinch roller. If the other rubber was bad so is the pinch roller. Period. Then see where you’re at. I thought I still heard squeaking in the video you posted. Did you clean the capstan shaft bearing bore and the shaft and apply a thin coating of proper lubricant? The dust washer looks filthy.
Honestly it’s so hard to tell what all might be happening, and it makes me nervous to get that engaged because you shared you had something connected incorrectly. There’s no telling what that connector does or if you may have damaged something by having it hooked up wrong. There is nothing safe about being hasty when working on something like a 244 or similar.
Maybe your motor drive circuit is failing. When the capstan motor is spinning can you grab the pulley and make its stop? Like does it feel weak or does it spin strong and it’s a fight to make it stop? It should be the latter. And if it spins too slow even when it’s not under load then there is likely some problem higher up with the DC servo that drives the capstan motor.
You can ask questions like “is it this?” Or “is it that?” But realistically understand we have no way to know. You’re not presenting a common problem, and none of us have the machine in front of us on a workbench with equipment to diagnose one what’s going on. I’d start with answering cjacek’s questions about the capstan thrust adjustment, and also get yourself a copy of the service manual. Next I’d replace the pinch roller. If the other rubber was bad so is the pinch roller. Period. Then see where you’re at. I thought I still heard squeaking in the video you posted. Did you clean the capstan shaft bearing bore and the shaft and apply a thin coating of proper lubricant? The dust washer looks filthy.
christiandaelemans
Active member
i bought a pinch roller rubber earlier today, i’m intending on replacing the whole rubber. i may take it up to a dude in nothern maryland to take a look. as for the capstan motor, i did that yesterday to see whether or not the motor is still wobbling while playing, and it definitely fought back. was not wobbling either, was just fighting the good fight. felt strong. the squeak i believe is from the needle that goes into the right cassette reel hole. it used to squeak very loudly, and before the pitch became totally unreliable, the transport section would literally twitch and make noise, and eventually every time it did so the pitch would change. now it just runs slow and does it without making noises.
my incorrect connection was me leaving the connection (male) unplugged that’s on the bottom corner of the transport area, kinda low down near the pitch control, while having its connector(female) plugged into the left corner’s smallest plug. that all sounds like gibberish, but basically, when undoing the transport, you need to take off a smallest plug, a wide plug, and a medium plug (left to right) on the bottom to be able to take it all out. i accidentally left the smallest of the 3 unconnected, while the pitch control (i think it was the pitch control, could have been the tape count) connector (female) was plugged into it. i took it apart again and connected it correctly after that, and i don’t believe i damaged any function because everything is working the same way it did before, just as incorrectly. though i guess i can never know, there’s a thing they say about learning things the hard way.
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sweetbeats
Reel deep thoughts...
I’ve learned a lot of things the hard way. Like roaching a mint Tascam 58 by plugging something in offset by one pin. That’s why I get so testy when I perceive somebody is being hasty. I fear the smoke.
Listen…you bought just the rubber donut to replace the old rubber on the pinch roller? Each to their own but that is the worst way to refresh the pinch roller. It’s the cheapest way for a reason. The reel table drive tires and belts are not critical to the performance of the tape in the tape path at least not directly. The pinch roller is. Those replacement pinch roller tires ensure less than factory spec performance in the area of wow and flutter. I never recommend them. If you can’t afford the best option which is a new roller from Athan Corporation then at least look into a precision rebuild of the original roller by Terry’s Rubber Rollers or look for a new OEM replacement with new core. That’s my advice and you can take it or leave it.
And when you say needle that goes into the right cassette reel hole are you talking about the take-up reel table spindle? The roundy trident-shaped thing that turns the right tape reel? Nothing on the transport should squeak. If it does it should be rectified…disassembled, cleaned and properly lubricated. Lubriplate 105 is my lubricant of choice for these types of things.
Listen…you bought just the rubber donut to replace the old rubber on the pinch roller? Each to their own but that is the worst way to refresh the pinch roller. It’s the cheapest way for a reason. The reel table drive tires and belts are not critical to the performance of the tape in the tape path at least not directly. The pinch roller is. Those replacement pinch roller tires ensure less than factory spec performance in the area of wow and flutter. I never recommend them. If you can’t afford the best option which is a new roller from Athan Corporation then at least look into a precision rebuild of the original roller by Terry’s Rubber Rollers or look for a new OEM replacement with new core. That’s my advice and you can take it or leave it.
And when you say needle that goes into the right cassette reel hole are you talking about the take-up reel table spindle? The roundy trident-shaped thing that turns the right tape reel? Nothing on the transport should squeak. If it does it should be rectified…disassembled, cleaned and properly lubricated. Lubriplate 105 is my lubricant of choice for these types of things.
cjacek
Analogue Enthusiast
Cory (sweetbeats) provides some excellent info and is absolutely correct that ideally you need to replace that pinch roller but all that I was suggesting, before putting more money and time into that machine, is that it is worth trying to restore some of the grip back into the pinch roller so that it doesn't slip, while squeezing the tape between it and the capstan shaft (which by the way should also be cleaned well) in order to see if the speed stabilises. I have successfully done this to hardened pinch rollers in the past on recorders which had speed issues and it did help, only as a temporary thing of course and eventually had to get a new roller because it's never gonna be as good (even after cleaning) as new rubber. I'm totally with Cory on this but all that I was suggesting is trying this "quick fix" and seeing if it helps, before putting more time and money into a machine which, as Cory pointed out, is hard to diagnose in its present state.
sweetbeats
Reel deep thoughts...
That’s a good point, Daniel…I understand what you were suggesting and I agree that would make sense to try that first.