Tandberg 6000X Stiff Operating Lever in Play Position

[DMcMahon]

Could not resist it, so took it apart, as you say very easy, and all clear now. I just had to remove 1 securing bolt for the transformer to move the transformer a little bit to get more finger access to the pulley. The top of the pulley has the integrated hexagon plastic nut.

The depth/length of the threaded section at the end of the table shaft sits a fraction above the top of the central boss that the shaft rotates in, so even if the pulley is fully tightened down, it does not make full contact with the top of the boss and there is fraction of vertical up/down play of the shaft, therefore allowing the table and pulley to rotate.

The clutch material is not as bad as I thought it was from a side view of the table, but still does not look good. I think I have got some cork that will be the right sort of thickness.

I will refit it, as it is first, to test it to benchmark how good/bad the clutch operation is before I attempt replacing the material, otherwise if I just fit new cork and operational results are bad then I will not know if it is due to the new cork or whether there is another issue.

[ricard]

Originally Posted by DMcMahon

The depth/length of the threaded section at the end of the table shaft sits a fraction above the top of the central boss that the shaft rotates in, so even if the pulley is fully tightened down, it does not make full contact with the top of the boss and there is fraction of vertical up/down play of the shaft, therefore allowing the table and pulley to rotate.

That's interesting. On the machines I've serviced I've always had to back of the pulley (or nut) a turn or two from the deepest position or it would be too tight. Perhaps they've got better tolerances on these 70s machines compared to the 60s machines with which I'm more familiar.

[DMcMahon]

After re-assembling it all back together, it now appears to have a lot more springy shaft play up and down (quite strong) with pulley fully wound down, maybe have disturbed something in the bottom half of the reel table.

Will have to have a fresh look at it another time.

[DMcMahon]

Having another fresh look, I cannot believe it is a year since my previous Post on this !

Found a new quite major issue, when the Joystick is moved to Play position the Pressure Roller does not contact the Capstan shaft, there is > 1mm gap.

The Pressure Roller arm is moved by a nylon roller (that travels up a channel) that is driven by a metal elliptical arm that the Joystick moves.

At Play position there is still more movement possible in the channel but the elliptical arm will not move the roller any higher in the channel. Manually pushing the elliptical arm up more does not help because the arc of the arm does not allow more contact with the roller.

There does not appear to be any obvious wear on the roller, elliptical arm or Pressure Roller so hard to see what the issue is, maybe some mechanical misalignment somewhere.

As stated in earlier Post virtually impossible to see/access the parts below the top plate and looks like it would be a mammoth task to remove the top plate parts.

I think I will compare to one of my other similar Tandbergs to see if can spot any differences that might explain the issue.

Has anybody seen similar before ?

David

[ben]

If you can manually push the pinch roller arm so it touches the capstan, then the problem is likely in the joystick. In one case, the cables from the counter bulb were fouling the linkage - check it.
There is a little bell ringing at the back of my mind as to another cause for this, will give it some thought after having a cup of tea!

[DMcMahon]

Thank you Ben for that input. It is diffiuct to clearly see but from a quick look the counter bulb cables are not fouling the linkage.

The shaft of the Joystick appears to be fully moving as far as it can (not quite into the end of the metal cutout) but even if it could move further I don't think it would help because the elliptical actuator is already at its highst point (contact wise with the roller).

Really would like to get the top plate (headbridge plate) off to check everthing, but despite removing more screws and bits and pieces the top plate is still solidly held by something in more than one place I think.

I think the only way forward is to compare to a good/working unit to see where the difference lies, hopefully my 2 other Tandbergs (3000X & 1200X Series will be good).

David

[DMcMahon]

After locating my 3000X (model 3041X) did quick comparison, but unfortunaetly looks like the 3041 has the same issue, the Pressure/Pinch wheel wil not reach the capstan (although gets closer) when in Play. Like the 6000X the Pressure roller arm can be manually pushed up to make the Pressure roller contact the capstan and drive the tape.

Like the 6000 no obvious adjustment or excess wear on the associated components. The elliptical actuator seems somewhat different in that the end curved profile that contacts the roller is turned upwards and shaped to fit the roller (as against the 6000 where the curve profile continues in same direction).

So disappointing, was hoping to see a difference that would explian why the 6000 is bad.

Not yet located my 1200X to compare to.

[DMcMahon]

Found and fixed the problem on the 3041X. While checking the various mechanisms found a sprung loaded lever was not rotating on its shaft due to hard/dried up grease.

This lever moves another spring loaded lever which in turn moves another sprung loaded lever which moves the position of the Pressure Roller.

The first lever that was gummed up is operated by the Start/Stop mechanical switch, switching it to Stop moves the Pressure Roller back from the Capstan shaft, i.e. just a mechanical Pause or Temporary Stop.

After cleaning and re-lubing working very well now, sort of obvious now that I have found it.

Am hoping it will be somewhat similar on the 6021X although I think the Start/Stop mechanisms are not identical.

[DMcMahon]

The 6021X Start/Stop is completely different. The Start/Stop switch is electrical and operates a solenoid that moves a mechanism that pushes up the Pressure Roller arm when Start is selected to move the Pressure roller to the capstan.

So looks like the issue was that I did not have the switch switched to Start ! however a new problem now, when switched to Start, the Pressure roller does now contact the capstan but struggles sometimes to rotate due to the pressure roller deforming, looks like the pressure roller has had it (too soft).

Will see later what it is like with tape.

[DMcMahon]

Loaded a tape on the 6021X and Play does mechancally work but the Pinch/Pressure wheel definately needs replacing as it is soft and deforms.

As they are expensive I need to see if the rest of the unit functions OK before considering getting a replacement Pinch Wheel. I will borrow the Pinch Wheel from the 3021X (same part number) to do further testing.

But it does not look easy to remove the Pinch Wheels. I assume you have to pull the Pinch Wheel pin/shaft out, but there is little of the shaft to grip onto and there is a double spring arrangement and washers that I am sure will be fun getting back in correctly on re-assenbly.

Rewind works but is noisy (and very squeeky when stopping), FFD does not work, sort of works if I press the Take Up spool down, need to revisit the Take Up reel table springy vertical play from Post 23.

[Welsh Anorak]

A related problem I have is that the joystick on mine won't stay in the 'free' position - it slowly returns to stop. Any idea why before I have to dismantle it further?

[ben]

Originally Posted by Welsh Anorak

the joystick on mine won't stay in the 'free' position - it slowly returns to stop.

I had one like that - it was counter bulb wires! Some rerouting and a cable tie cured it. Also I have another with a similar problem but I suspect mechanical wear.

[DMcMahon]

Removed the Pinch Wheel from the 3041X to use as a donor for the 6021X, it was just a case of pulling out the shaft which was a bit fiddly.

Removed the bad Pinch Wheel from the 6021X and also removed a few other gummed up bits for cleaning and re-lubing. Also cleaned and relubricted the Joystick assembly and various bits driven by the joystick, generally now Joystick operation is a lot easier than it used to be.

Getting the Pinch Wheel parts back together is proving difficult as expected, getting the 4 washers (2 thicknesses) in place on the shaft and the double spring arm in the tiny slots in the shaft with the Pinch Wheel in place fighting against the spring pressure is proving a test of patience.

Not 100% sure about the correct position of the washers, literal interpretation of the 3000/1200 drawing (the 6000 manual does not have a similar drawing) appears to show the washers either side of the spring (on both sides) but this does not feel right to me.

It was impossible to see the position of the washers during the Pinch Wheel removal on the 6021X, on the 3041X on one side the washers were either side of the spring but on the other side the spring was on the outside of the 2 washers.

I am trying to refit it with the spring on the outer side of the washers on both sides.

[ben]

You might have to make some kind of tool to assist in a situation like this. You can bet they had one in the factory!

I haven't yet had the need to do one of these pinch rollers but I'm dreading the day!

[ricard]

The washers should indeed be on either side of the spring. The ones immediately on either side of the pinch roller are there to stop the pinch roller scraping against the spring, and the outer ones are there to stop the spring scraping against the pinch roller arm. Some machines even have a fifth washer made of some white plastic material (as opposed to the others which are some form of fibre material), which goes on the underside, but I'm sure exactly where, I think it was directly below the pinch roller to act as some form of axial bearing. I usually leave that one out as it's bad enough getting the other four in the right place!

I'm at a loss to understand how they were supposed to be efficiently mounted in the field. At the factory as Ben says they must have had some tool or jig, and besides it could be done before fitting the whole pinch roller arm assembly into the machine. But I've never seen any reference to any special tool to make field replacement efficient.

I've got a screwdriver which I've made a little notch in the side of, which helps hold the spring out of the way while working, and a friend of mine has made a little clamp out of a piece of metal folded into a 'U' for the same purpose.

The procedure I use is to first pull the spring to it's normal operating position and hold it there (with the aid of some tool; here is where a clamp comes in handy as it frees one hand from having to hold the spring which otherwise necessitates the rest of the procedure to be executed using only one hand), then push the outer washers into place, the spring normally pressing outwards against the pinch roller arm housing so as to hold them. Then, using tweezers I lay the washer on the underside of the pinch roller in place, then carefully lay the pinch roller in place without disturbing the washer, by pressing it upwards as far as possible. After that, the washer immediately above the pinch roller is maneuvered into place, and finally the shaft is pressed through the whole assembly. I then have a good look to see that the washers are in the correct place before finally maneuvering the shaft into it's correct position so that the slots in it engage with the spring.

I have no idea if this is the best way to do it but I can't think of anything better. I wholeheartedly concur that it indeed is a test of patience. (It's like it's a compensation for ease of which a main belt change can be effected on these machines! ).

[DMcMahon]

Thank you ricard for clarifying the correct position of the washers, so the drawing is correct, it does make sense now.

Luckily it does not have the fifth white washer.

I need to get back to it after doing other things, hopefully my patience reserve has been well topped up.

David

[DMcMahon]

After more attempts still struggling refitting the Pinch Roller parts, particularly the rear washers, they keep dropping/falling down, have been trying using bent over piece of wire from the rear to hold the washers in place.

Would be a lot easier if the Pinch Roller assembly was off the machine. Have tried to remove it but unable to budge the strong circlip that holds the assembly onto mounting shaft.

Will get there eventually.

[ricard]

Are you attempting to mount the washers while the machine is standing up? I always have the machine lying on its back (but have never tried the other position though).

I wonder if it would help using small dabs of grease to help hold the washers in place, as long as one doesn't get any on the rubber surface. Never tried it though, precisely for fear of that.

[DMcMahon]

Mostly yes because find it a little easier to see it but have tried it horiziontal as well. Have now tried a bit of grease but still finding that the rear washers move when attempting to get the sping inbetween them.

After numerous attempts ran out of patience and decided the only practcial way I was going to do it was to remove the Pinch Roller assembly first. So had another go at removing it and after some fun got it off, the Bias Head assembly was particulrly difficult to extract from the assemby, which was necessary to be able to lift the Pinch Roller assembly off its mounting shaft. Also good to get the asembly off because it is somewhat stiff rotating on its shaft.

David

[DMcMahon]

Aftr many painful iterrations got the Pinch Roller fitted with the washers in the correct place, during this one of the Turbax fibre washers got broken so replaced.

Presently trying to put the Pinch Roller assembly back together, not easy getting the Bias head bits and associated bits all back together correctly.