One interesting thing I noticed (and I'm investigating at this very moment) is the arrangement of the head load armature. A spring-loaded arm will swing down and push the felt pad against the media, which brings it into conformity with the head. However, there's a little thing on the lever that touches the plastic head load mechanism that I posted links to earlier.
When the head load solenoid is retracted, the felt pad arm is lifted up enough that the disk can slide in and out freely. When the head load solenoid fires, the whole thing comes down and it's clearly supposed to push on the media. However, I think in both my drives it doesn't touch it, or if it does it only barely touches it. I'm thinking perhaps the armature has to come down further. That being said, at least once I tried doing that, manually letting the arm come down, and it didn't improve the observed behavior. It's possible something else was happening then too, so I'll retest. -Dan On 2/6/16, James Attfield <ja...@attfield.co.uk> wrote: >> Date: Sat, 6 Feb 2016 00:46:33 -0500 >> From: Dan K <100dash...@gmail.com> >> To: "General Discussion: On-Topic and Off-Topic Posts" >> <cctalk@classiccmp.org> >> Subject: Re: Calibration of 8" floppy drive? >> Message-ID: >> <CAAQ+N0XNG=NnWGRnt8oxN4WeXTuoLCXPO9BQRn9oaSjZfVNW >> 5...@mail.gmail.com> >> Content-Type: text/plain; charset=UTF-8 >> >> Are there any good alternative solutions I can do to replace it? I'm >> sure I don't want the plastic touching the disk media. >> >> -Dan > > Seems like eons since I learned to align PerSci 299B's with Dysan alignment > disks and 'cat's eyes' on a 'scope :) > > I echo the other sentiments here - do NOT undo or unscrew anything relating > to head positions especially involving allen (hex) screws unless you have a > 'scope, an alignment disk, a very good quality set of hex screwdrivers > (keys > will normally NOT suffice) and a modicum of experience. Granted, lead screw > single-headers are a little easier to do than voice-coil double-headers but > if you don't have to get into it then don't - explore all other options > first. > > I'm afraid my TM-848's are double headers so the top head provides the > pressure but back when the drives were single headed felt pads did the job > of the second head. The tension was provided by the spring, the pad just > prevented scoring. I do NOT speak from experience BUT if I had to use > anything the kind of small felt pads you can get from hardware stores (e.g. > B&Q in the UK) seem remarkably similar in composition and would be worth a > try especially if you have one original to compare. Cut to shape, most are > self-adhesive too - bonus. > > HTH > > James > > >
