[Coco] Diskette Flipping Question

[Gene Heskett]

On Thursday 13 September 2012 10:48:18 Retro Canada did opine:

> Hi,
> 
> I just got a 36-3029 drive unit using it with a FD-500 interface in my
> Coco3. It works nice, but I noticed that I cannot flip the disk to use
> the other side, since this drive is single sided. What is the problem
> ? Do I need to make another alignment hole on it ?
> 
> The apple //c and C-64 don't have this problem I can flip and use both
> sides with no problem.
> 
> Thanks,

Perhaps the write protect notch isn't cut out on the other side of the 
sleeve?  These controllers also use the index hole when formatting, so that 
will need to be mirrored in the sleeve.  Remove the disk itself while 
punching the mirrored index hole in the sleeve of course.

I can't think of any other reason it shouldn't work.  There may be a 
difference in turning force required since the fuzz inside the sleeves 
tends to bend over in the normal direction, and reversing the disk spin 
could make a difference enough to cause slippage if the clamp rosette has 
shrunk with age, or the clamp spring is weakened from being left open for 
years.

With these drives at the age they are, we are somewhat stuck, leaving them 
open when empty puts tension on the clamp spring, which could weaken over 
the years, and closing them when empty puts pressure on the usually nylon 
rosette, whose petals will then cold flow, effectively shrinking it until 
it no longer precisely fits the disk hole, allowing the disk to be spun off 
center and likely damaging the edges of the hole too.

A classic chicken vs egg for us.  I leave them open since I can always put 
a bit of stretch back into the spring, but making the nylon rosette un-warp 
itself isn't feasible.

Another factor might be the belt condition in belt drive models.  Those 
belts are made out of unobtainium today, but I have managed to rescue a 
cdrom drive whose tray drive was slipping that I needed a while back, by 
cutting a small piece out of it, and super-gluing the butt ends back 
together.  5 years later that drive is still working!

Cheers, Gene
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