FDS Disk Bares All!

[Stephen]

I have a disk that is in rough shape and already shows signs of separating. With a little extra time on my hands I decided to open it up (spoiler, there wasn't any surprises).

For your viewing pleasure:
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Compared to the patent photos:
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Truthfully, my primary goal was to confirm measurements of the disk surface. After a little super glue everything is back to normal and the disk will continue to serve as my "write tester".

[P]

Pretty cool that it still works! Thanks for sharing!

[theoakwoody]

How hard would it be to 3D print the shell and repurpose the internals from an unformatted 3.5" disk cut down to size?  Probably wouldn't work but would be nice to have new disks available.

[Stephen]

How hard would it be to 3D print the shell and repurpose the internals from an unformatted 3.5" disk cut down to size?  Probably wouldn't work but would be nice to have new disks available.

I don't think the hub from a 3.5" floppy will work. If the dimensions are comparable then it should be possible.

As far as 3D printing disk shells, it will depend on the design. I can make a 1:1 copy of the disk shell in 3D but maybe someone else will want to optimize it for 3D printing (e.g., FDM).

It's a fun idea

[P]

It is indeed. If it would work, one problem we would be facing is that new 3.5" disks are also harder and harder to get your hands on. I have no idea how the magnetic film is manufactured.

[-N2]

if it were possible would it be worth building a knock off of the original FDS drive using a common 3.5" 1.44MB PC Floppy drive? one with something like an Arduino it it to handle the interface between the Famicom RAM module and the Floppy drive itself. 

[P]

I don't think that would work, at least not mechanically considering that the QD-drive doesn't use a stepper motor like a conventional FDD do. I don't know if the magnetic head could be used though.

[Skawo]

Thanks for this post; it gave me the confidence to try surgery on a junk Metroid disk.

The disk had big scratches on the inside and a line where it appears something hit the disk and created a crease in it.


I actually managed to load and dump the disk once, only on my best of the best FDSes, but it made weird noises and gave a terrible FDS Stick score. I thought to try to rewrite it, but, sadly, it would not do it properly, and so it never loaded afterwards.

The Roland QD I had came to the rescue, and after swapping the insides, and a little bit of superglue like you said, the disk now works like new.

I can also, thus, showcase how a regular QD disk looks inside:

Unsurprisingly, not a whole lot different.


Kinda wondering the same thing about maybe cutting out another floppy to size, but I dunno how I would replace the spindle. Supposedly, there is a tutorial on the back of some magazine that told how to make an FDS Disk out of a 5 inch floppy, but I cannot for the life of me find this info anywhere again.

[ericj]

Supposedly, there is a tutorial on the back of some magazine that told how to make an FDS Disk out of a 5 inch floppy, but I cannot for the life of me find this info anywhere again.

Is this what you're referring to?

[Skawo]

That one I did find.
I dunno, I swear I saw some forum post somewhere that said you could cut out a new magnetic disk, but maybe I misread it.

[Stephen]

The disk had big scratches on the inside and a line where it appears something hit the disk and created a crease in it.

I suspect it may be possible to repair those creases with two heated / weighted plates. I have some experience  making heated tools so I plan to revisit this at some point.

[Skawo]

That'd be nice. Dunno if this particular disk is salvageable, though. It's not just the crease that's the problem, I think, as there's a load of scratches and splotches on it.

Speaking of, I have another faulty disk that behaves really strangely; it loads properly most of the time but then suddenly it stops doing so. Flipping the disk over and reading side B helps to make side A work again. Sometimes side A just works again after ejecting it and reinserting a few times.
FDS Stick score fluctuates on it from being a near perfect 0.9-1.0 to as far up as 3.5, with the graphical representation increasingly messed up.

My only idea is that maybe something's stuck on the inside that occasionally makes it harder to turn the spindle? Not really able to detect that when turning it with my fingers, but the effect's probably slight. I mean, if the magnetic surface itself was the problem, it wouldn't fluctuate from being perfectly readable to completely unreadable and back, right?

Thoughts?

[Stephen]

My only idea is that maybe something's stuck on the inside that occasionally makes it harder to turn the spindle? Not really able to detect that when turning it with my fingers, but the effect's probably slight.

This is the exact conclusion I reached. I found some disks have sticking points; I usually hold the spindle and give them a few spins to see if I can find it. If I do then I usually go back and forth over that spot with force, moving the spindle closer and further from the center of the cutout.

Be mindful that this can introduce scratches depending on what exactly is in there.

[Skawo]

Hm, well, maybe just opening it would be safer, then? Hopefully it'd be obvious once I could see the inside.

EDIT: Decided to go for it, and, well, indeed, the problem was self-evident inside. Part of the backing has unglued from the plastic and was rubbing against the disk. Not entirely sure if it can be easily stuck back down, though, as any excess height I add will naturally rub against the disk all the time.

EDIT2: Added a miniscule amount of double sided tape to stick the thing back down and then cut off the hair that was coming off the backing. It seems to work, although I'm hesitant to glue it back together yet. Will wait and see.

[theoakwoody]

This thread is amazing.  I really hope you guys figure out how to Canabalize other magnetic disks and drop them into new 3d printed fds shells.