[Coco] FD-502 replacement drives

[Mike Delyea]

Try it with just 1 drive installed.  Obviously I don't know the origin of
the drives and case but is it possible it was a single drive at on time and
someone added a second drive later?

On Mon, Dec 18, 2017 at 8:48 PM, Gene Heskett <gheskett at shentel.net> wrote:

> On Monday 18 December 2017 17:56:17 John Mautz wrote:
>
> > Gene,
> >
> > The drives move freely and make the normal head movement noises.  I
> > just get a ?IO ERROR when reading the disk. (Dir works on my 501
> > setup).  I cleaned the heads as you described with same result.
> >
> > Thanks.
>
> Humm, I wonder if the rosettes, the white nylon gizmos used to clamp the
> disk have collapsed from long storage in the closed position, which has
> been a problem for me when first using a drive I've not used before, and
> that would reduce the grip needed to spin the disk, and affect the
> auto-centering, which would allow the disk to run eccentrically. Are any
> of the disks showing damage such as a folded edge on the centering hole?
>
> Looking at the rosette from the side, there should not be even a hint of
> the fingers folding back. The original idea was that they would be
> pushed in 2 or 3 thou such that its a tight fit within the socket of the
> spindle when closed.  But years of closed pressure against the outer
> flange face, which gradually bends them back to where the disk can seat
> off center a few thou. Since those are made out of pure unobtainium,
> theres not a heck of a lot that can be done.  Thats called "cold flow"
> and it would take 10 years worth of pressure in the other direction to
> put the correct 'spring' back into them. By now they have got to be as
> brittle as a glass tree ornament.
>
> Another possibility is flea clip miss-programming on the drive. IIRC they
> can have the read channel enabled by the motor on, but since the motor
> on is usually a common to all drives signal, then the read from one
> drive might be swamped by noises from the other. They can usually be
> converted to read live when drive select for that drive is live. You
> might have to scour the net with google and see if you can find a chart
> of what jumper is what for those drives. For double sided drives, you
> may have to replace the controller to drive cables drive connectors with
> connectors that don't have missing contacts like the shack cables did.
>
> When changing clip positions, make sure that all motors still run because
> neither the stock SS controller driver or any of the os9/nitros9 drivers
> have a spin-up delay when changing drive targets to cope with drives
> that are shut down and then restarted again.
>
> > On Dec 18, 2017 5:44 PM, "camillus gmail" <camillus.b.58 at gmail.com>
> > wrote:
> >
> > Hi Gene,
> >
> > Are you looking for the 5.25 drives, or the smaller 3.00 inch drives?
> >
> > I have two of the 5.25 drives and to be honest can't use them because
> > I do not have any floppies anymore...
> >
> > If you send me 1 floppie I can test them, and maybe we can swap.
> > I need a 512 triad memory upgrade, which I believe is sold by Mark
> > Marlette for $50.00.
> >
> > Let me know if interested...
> >
> > cb
> >
> > On 12/18/2017 2:24:31 PM, Gene Heskett <gheskett at shentel.net> wrote:
> >
> > On Monday 18 December 2017 14:27:13 John Mautz wrote:
> > > Hello,
> > >
> > > I have had two FD-502 enclosures for a few years now and when I
> > > installed them today, neither drive worked. I do have and FD-501
> > > with 2 drives and it seems to work (I don't have a lot of disks to
> > > test with). I would like to restore my FD-502 to a 2 drive system in
> > > working order. Why, because the drives are supposed to be double
> > > sided.
> > >
> > > Anyone have 2 working FD-502 drives they would be willing to part
> > > with?
> >
> > Are you able to remove the drives?
> >
> > If so. you will likely find the lubricant on the rails the head
> > carriage slides on, a dried up caked mess. Clean those rods with paint
> > store alcohol and put a thin film of vasolene or similar very light
> > grease on them again. If the motor to head carriage connection is a
> > very thin steel tape, it wouldn't hurt to clean it also as an old film
> > of cigarette smoke will change its diameter enough to miss track on
> > the inner tracks. If the motor is on the rear of the drive and has a
> > long screw shaft, clean the gunk out of the groove in the shaft, and
> > recoat with vasolene, ditto the tracking wire and the bronze leaf that
> > serves as the drive nut. All this needs to be clean and lubricated.
> > Quiet, you can't alway hear them stepping drives, are surefire signs
> > the drive is due for a clean and lube job. The noisy drive is the one
> > thats stepping accurately from track to track.
> >
> > While you have access, wet a q-tip and run it between the head faces
> > to clean the heads. If any color comes off on the q-tip, toss it, get
> > a new one and "wash, rinse, and repeat" till the wet q-tip stays
> > clean. But do not bend them for a better view. Just slip the wet q-tip
> > between them.
> >
> > > or
> > >
> > > Anyone know of a good source to find replacement drives? (Mitsumi
> > > Elec. Co. - D502).
> >
> > These are genuine antiques today, buyer beware.
> >
> > > Oh, and yes I have and email out to see if the SDC master (Zippster)
> > > has any CoCoSDC's avail for sale.
> > >
> > > Thanks for the help.
> > >
> > > John.
> >
> > Cheers, Gene Heskett
> > --
> > "There are four boxes to be used in defense of liberty:
> > soap, ballot, jury, and ammo. Please use in that order."
> > -Ed Howdershelt (Author)
> > Genes Web page
> >
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>
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> Genes Web page <http://geneslinuxbox.net:6309/gene>
>
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