VOGONS


First post, by wbahnassi

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Hi guys, I have a TEAC FD-55GFR 5.25" floppy disk drive that is giving bad grinding sounds when its disk spin motor operates. The drive was super dusty, so I'm betting there are happy dust bunnies inside the motor 😅

Anyways, for the life of me I couldn't figure out how to disassemble the motor to clean it from the inside. I fully disassembled the drive except for the spin motor and its board. I removed all visible screws but both the board and the motor are still fixed to the drive.

The only screws I couldn't undo are the ones at the bottom of the motor plate. They are small but VERY strongly tightened. I just can't have them budge.

Anyone has experience disassembling this thing? Ultimately I just want to clean it and have its noise gone. I tried WD-40 bit found no improvements at all.

This is the motor I'm referring to:

The attachment s-l1600.jpg is no longer available

Cheers!

Turbo XT 12MHz, 8-bit VGA, Dual 360K drives
Intel 386 DX-33, Speedstar 24X, SB 1.5, 1x CD
Intel 486 DX2-66, CL5428 VLB, SBPro 2, 2x CD
Intel Pentium 90, Matrox Millenium 2, SB16, 4x CD
HP Z400, Xeon 3.46GHz, YMF-744, Voodoo3, RTX2080Ti

Reply 1 of 7, by konc

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After you finish cleaning and put it back together I'm interested to learn how the alignment went, if you've really fully disassembled it.

Reply 2 of 7, by wbahnassi

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That's not a big deal. Just restore the stepper motor at the same offset it was at before. A close-up camera shot on the alignment pegs works great here, so I'm not worried. But this grinding noise is driving me mad, and of course it's not good for the drive on the long run.

Turbo XT 12MHz, 8-bit VGA, Dual 360K drives
Intel 386 DX-33, Speedstar 24X, SB 1.5, 1x CD
Intel 486 DX2-66, CL5428 VLB, SBPro 2, 2x CD
Intel Pentium 90, Matrox Millenium 2, SB16, 4x CD
HP Z400, Xeon 3.46GHz, YMF-744, Voodoo3, RTX2080Ti

Reply 3 of 7, by wbahnassi

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Heh, found the maintenance manual for the drive: https://www.ndr-nkc.de/download/hard/FD55_maint.pdf
Page 4124 shows how to disassemble the spindle motor... Wish me luck 😁

Turbo XT 12MHz, 8-bit VGA, Dual 360K drives
Intel 386 DX-33, Speedstar 24X, SB 1.5, 1x CD
Intel 486 DX2-66, CL5428 VLB, SBPro 2, 2x CD
Intel Pentium 90, Matrox Millenium 2, SB16, 4x CD
HP Z400, Xeon 3.46GHz, YMF-744, Voodoo3, RTX2080Ti

Reply 4 of 7, by Deunan

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That manual tells you how to swap the entire motor assembly, not how to open it up. TEAC used several different motor assy's, the one you have is newer than what's in the manual (but there are even more modern variants).

These 2 screws that hold spindle to rotor are not supposed to come out. To ensure that the threads are locked with some pretty strong glue and the head of the screw usually can't take the torque to break it loose without suffering damage. Also I can't remember now but on the models with one central screw it's threaded CCW, as additional precaution and these two might also be. In short, you are more likely then not to ruin the screws before you come anywhere close to removing them.

I might have a few suggestions if you end up with mangled screw heads and further need to disassemble anyway.

Reply 5 of 7, by wbahnassi

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I managed to disassemble the spindle motor cover. Yes the two small screws holding it are tightly secured. But I was able to undo them with good force and the proper philips head without issues.

Once the disc cover is removed I got access to the coils, and in the center there is a metal cylindrical core with a thick metal ring around it. Those two pieces are attached to each other via a tiny bolt that penetrates them from one side. I think the ring floats on the bearing balls so I wanted to also pull it out, but I couldn't remove the bolt. It's so tiny and is wedged in by force. The best I could do was again to try and spray some WD40 in there, but I don't think the liquid managed to reach the friction points, as I found no difference.

So yeah, after all the digging, dead end. Though maybe I can devise a tool that can push out the tiny bolt... Anyways I put everything back together and the drive works fine. Just still noisy whenever the spindle motor turns. I have another NOS Teac drive and that one is super silent..

Well.. still cool experience 😅

Turbo XT 12MHz, 8-bit VGA, Dual 360K drives
Intel 386 DX-33, Speedstar 24X, SB 1.5, 1x CD
Intel 486 DX2-66, CL5428 VLB, SBPro 2, 2x CD
Intel Pentium 90, Matrox Millenium 2, SB16, 4x CD
HP Z400, Xeon 3.46GHz, YMF-744, Voodoo3, RTX2080Ti

Reply 6 of 7, by Deunan

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wbahnassi wrote on 2023-01-15, 13:34:

So yeah, after all the digging, dead end.

You sure it's the rotor noise? Did you test the bearing for friction when you had the cover with magnet unscrewed? Because it's the only thing that can be noisy in there - and if it's toast then frankly you should swap the entire assembly rather then replace the bearing. It's usually not worth the trouble (including getting the hub sit perfectly without wobble) unless the drive is unique, and TEACs are not.

Usually the noise is either the motor cover rubbing against something or the plastic hub under the clamping arm. BTW the motor can rub against any flat surface the drive rests on, many of those need extra clearance of a milimeter or two and really need to be hanged via side screws.

Reply 7 of 7, by wbahnassi

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Yeah unfortunately the noise was still coming from the metal core I exposed. The cap was all clear indeed. Though, the motor seems to turn very smoothly actually. If I flick the inner cylinder/ring it turns smoothly and keeps going for a second or two by itself, albeit with the grinding noise. Given how hard it was to try and get there, I'm surprised how anything could've reached those bearing balls. They're quite unreachable, so I'm puzzled as to how dust could have gotten in there so they came to be noisy.

Turbo XT 12MHz, 8-bit VGA, Dual 360K drives
Intel 386 DX-33, Speedstar 24X, SB 1.5, 1x CD
Intel 486 DX2-66, CL5428 VLB, SBPro 2, 2x CD
Intel Pentium 90, Matrox Millenium 2, SB16, 4x CD
HP Z400, Xeon 3.46GHz, YMF-744, Voodoo3, RTX2080Ti