Vertical vs horizontal operation

[ricard]

A friend of mine asked me if there was any preferred orientation (vertical vs. horizontal) regarding his Revox B77. I can't remember ever hearing about any preference from a performance point of view, providing the machine is designed to operate in the required orientation - indeed, professional machines often seem to be mounted almost flat, at a slight angle, I'm thinking because it makes it easier to reach everything.

So I'll put the question up here - are there any reasons to operate a machine like the B77 in any specific orientation?

[stevehertz]

If there are feet on two surfaces, then the manufacturer is clearly enabling the machine to be used in either orientation. In theory I suppose one may offer greater longevity than the other, but not one that concerns the manufacturer. You're good to go on both.

[Graham G3ZVT]

Originally Posted by stevehertz

In theory I suppose one may offer greater longevity than the other, but not one that concerns the manufacturer. You're good to go on both.

Motor armatures, capstan spindles and pulleys will have some slop in their bearings, and I would want gravity to bias them towards the lower thrust bearing, so operation at exactly 90 deg ie upright, might be slightly detrimental to performance due to these items, particularly the capstan/flywheel, axially "wandering".
Hope that makes sense.

[Radio Wrangler]

Because of the use of three Papst outer-rotor motors, there isn't the easy way out of having a single-ball thrust support so there is no advantage to being flat on their back.

A nice slope will be fine.

David

[williamsunique]

On the odd occaision I have measured wow and flutter with a deck in both positions. The figure was always slightly better in the horizontal position. This was with decks that were designed to be used in either orientation.

Paul

[barrymagrec]

I once read that Norman Leevers didn`t think it was possible to make a tape deck work optimally in the vertical position.

Having said that plenty of Leevers Rich tape machines were supplied for rack mounting.

Vertical operation is a pain for editing of course but hardly anyone does that anymore, beyond sticking leaders on.

[brenellic2000]

As Rambo1152 eludes, a thrust bearing on a horizontal deck's motor, relying on gravity and uniform centrifugal forces (such as a wrist-watch balance wheel) is easier to design, maintain and lubricate (thus longer lasting) than the far wider/larger weight supporting roller bearings on a horizontal shaft - for which additional end bearings are required.

Whether in reality it makes any significant or operational difference to a tape deck is another matter!

[TIMTAPE]

Originally Posted by ricard

... - indeed, professional machines often seem to be mounted almost flat, at a slight angle, I'm thinking because it makes it easier to reach everything.

For transferring tapes optimally, horizontal allows optimal viewing of the tape, tape heads and guides as the tape plays through. It also allows much easier cleaning access to the tape path, and you can actually see if all the dirt has been completely removed from each component.

Speaking of viewing and cleaning the tape path, the A77 was a shocker. The B77 was improved but still not great. In both models visual style trumped functionality. The higher specced A700 and PR99 retained an "ugly but accessible" headblock.

Reels have flown off a vertically oriented deck due to failure to lock the reel retainers. It can happen to anybody. With horizontal orientation, the reels should at least stay put from gravity alone.

[DrStrangelove]

[QUOTE=TIMTAPE;1551661]

Originally Posted by ricard

Reels have flown off a vertically oriented deck due to failure to lock the reel retainers. It can happen to anybody. With horizontal orientation, the reels should at least stay put from gravity alone.

You haven't lived until you've seen a 10" spool of half inch computer tape do that in high speed rewind.

I hated those machines.

[Kentode]

The capstan of the Revox B77 has two domed washers ( items #6 in the picture) which apply preloading, l would expect this to remove any endfoat, whether in a vertical or horizontal position.

[Alphonse01]

Hi Kentode,

in the diag given, the belville washers (6) shove against the Low Friction Washer (5). The Low Friction Washer shoves the collar (3) against the Sintered Bronze Bearing (Not Shown). The Thrust Bearing on the capstan shaft (4) is in the gap in the centre of the collar. There is some small endfloat. If there were no endfloat at all, the thrust bearing would be gripped and the resultant drag would play havoc with speed and Wow/Flutter figures.

I personally prefer the vertical position as the reel motor bearings will the have radial forces to deal with. If the machine is horizontal the weight of the reel will be an axial force which the roller bearings will not be as hardy.

All a matter of opinion/taste of course.

Alphonse01

[Kentode]

Thank you, Alphonse for the explanation of the other components in the capstan motor, that makes sense.

The B77 comes with feet on the back and base, so presumably Revox considered it was capable of operating in both directions.