Re: Using both sides of DS DD disks

[mjmahon@aol.com (Michael J. Mahon)]

George from Michigan wrote:

>Exegete <millers@noneofyourbusiness.com> wrote in message
>news:<3DC29E5E.6030507@noneofyourbusiness.com>...
>> David Wilson wrote:
>> > mjmahon@aol.com (Michael J. Mahon) writes:
>> > 
>> >>The only possible impact to the drive would be the (theoretical)
>> >>re-exposure to dirt trapped by normal rotation on the disk sleeve,
>> >>and now (theoretically) released by counter-rotation.
>> > 
>> > 
>> > True. There is also the possibility of the head pressure pad on a
>> > single sided drive causing damage to the disk surface. Provided you
>> > never turn the diskette over you don't notice it but once you do
>> > you are either trying to record on a damaged surface or worse it starts
>> > to damage the already recorded side 1. There have been instances where
>> > the pressure pad has fallen off a drive.
>> 
>
>> Ah, and now to drift a bit from this thread: I've had pads fall off, and 
>> others that were compressed so much that they weren't putting enough 
>> pressure on the disk to keep it against the head. So, here's my 
>> question: where can someone find replacement pads?
>> 
>> Roy
>> 
>> > --
>> > David Wilson  School of IT & CS, Uni of Wollongong, Australia
>> 
>> 
>
>Hi,
> With drives so cheap replacing one should not be a problem. You could
>reglue the old pad if you still have one. For those that are too
>compress with not enough pressure. You can uncompress them with a pin.
>You can insert it at about a 30 degree angle and lift. You do not need
>to insert it all the way in. Only about 25% of the thickness. You only
>need to fluff it out about 1/8 inch.

Since a new one is only about 1/16", that seems a little much.  ;-)

Actually, it's just moderately high density felt.  This is not hard to
find in sheets that can be punched to produce new pads.  Super Glue
will do a fine job of attaching them after the residue of the old pad is
removed.  There is nothing critical about the material (as long as it
doesn't "shed" excessively) or its thickness (since there is plenty
of "slack" in the spring that presses it onto the top of the diskette.
The main reason for making it as thin as is practical is so that it
does not shear off after extended contact with the rotating disk.

>  On another note some disk do not spin well. That is some require a
>lot more torque than others.

This is a result of compression deformation of the diskette sleeve.

It is easily fixed (with a little practice) by rubbing the edges of the
diskette across the edge of a desk, carefully (especially near the
cutout), so as to spread the sleeve slightly.  One pass with
moderate pressure is usually sufficient. This will greatly reduce
the torque required to rotate the disk.

> Disks with out the metal hub should not
>be used since this also part of the clamping. 

While hub rings do certainly aid in clamping (and, more importantly, in
centering), diskettes without hub rings (which are plastic, BTW, not
metal) work just fine in any properly adjusted disk drive.

-michael

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