Floppy disc and floppy drive problems fixed saga

[Bignumbas]

Now that I had repaired my 6128 I had need of some 3" floppies.
I had 19 floppies from a second 6128 I bought but after formatting them only 2 were good and the majority had one side that was unusable. I had washed them and used a magnet to wipe them all to no avail. I then bought 14 from Gumtree for AU$82. Now I had 4 usable disks and the bad pile had doubled, never was I going to buy 30 year old Amstrad floppies again, HXC gotek was the way forward now.
The new 6128 had no drive belt when it arrived and after it was installed I decided to give the disks one more try and to my amazement I now had 90% success rate. Wow!!! Why???
These discs would not work in the original drive however so I assumed the 12v reverse polarity has damaged it. The answer to my bad discs?
Then the drive that was working developed a screech from a dry bearing. I had to resort to my magic fix for bush bearings. Technically you have to immerse the bearing in oil that is heated to 150C+ to re-oil them. This does not work on press fitted modern motors like disk drives and Chinese house fans. I developed a method whereby I heat up the bearing in situ with a hot air gun (on low speed, high heat) while dabbing oil on the bearing.
Now my floppy drive purrs away again.
While researching repairing drives I had come across software called RPM that checks the drive rpm which should be 300.
I checked the re-oiled drive and found it to be 260rpm so that is why it worked. Ahh... that Eureka! moment....
The other drive that did not work was to fast at around 324rpm, it would always throw back a track 0 sector 0 error. I had tried to fix this by tweaking the head alignment to no avail, now I knew why.
Now they both run at 300 +-2 and can read each others disks.
I now have 31 working disks, 8 or so have some bad sectors and two were beyond repair with flaking coating. A marked improvement over 4 good disks and 29 drink coasters.
In the process I have learnt that CPM will not copy disks from an HXC gotek and that Discology is the most reliable copy program for CPM boot disks and other game disks.
Multi Mark is brilliant for formatting and marking bad sectors on otherwise throw away discs.
In the midst of this I unknowingly dropped the read/write pin out of the re-oiled drive when I replace the drive belt.
So I include some photos of it. I think a Stainles Steel (Inox) ear stud could be used to replace it
I measured it to be 10mm x 1.1mm and I thought that it was an ear stud when I found it on the workbench, now I know better
All I need now is one factory made disk to check the aligment properly


So if your not having much luck with 3" floppy discs check your drives.

[Bryce]

Good to hear you have everything up and running again. A tip for the future and for others: Always check the RPMs first, it's much more likely to be the reason for not reading disks than bad head alignment.

The write pin dimensions have been documented here: http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/help-i-changed-the-drive-belt-and-now-my-disk-drive-is-suddenly-read-only/

Bryce.