FDS: Problem aligning the spindle hub?

[Da Bear]

Like many others, I used this guide to change the belt in my FDS and to adjust the spindle hub.
http://www.famicomdisksystem.com/tutorials/fds-repair-mod/belt-replacement-adjustment/

The belt change was easy, but when it came to adjusting the spindle it wasn't so easy anymore. I turned the gears listening for the click sound and then I rearranged the spindle.
But it didn't work! No matter how much I adjusted it wouldn't read my disk!

So, I thought it must be a much simplier way to adjust it. How do they do it in the factory?

It's really simple and none of the guides I have seen have taken this in to consideration.

First, do as the guide says. Turn the gears and listen for that click sound.
Then, you must locate a small hole in the gear and position it like in the image below. You don't have to turn the gear much to find and center it.


I belive that on the factory, they have a special tool to lock the gear in place and then placing the spindle hub where it should be.

Once you have located and centered the hole, hold the gear firmly with your fingers and adjust the spindle hub like in this picture.



BANG! Worked on the first try. These pictures show how it it adjusted when it's working.

So if you have problem adjusting the spindle, please give this a try and let me know how it worked out.

[ericj]

Nice work! I'll be trying this out next time I have to replace a belt and will get my site updated to reflect this method.

I'd like to find a way to easily do this alignment without having to remove the disk carrier mechanism, since I know a lot of people wouldn't be comfortable doing that and re-assembling it correctly. 

[fredJ]

I don't know what the problem is 

You listen for the click sound, then you move it back again as far as you can (won't be much). Then hold it there and align as in the picture...

You don't need to remove that black plastic carrier thing actually. Since the correct alignment can always be found, the gear can be lifted with the black carrier attached. It fits just barely to remove it. Then put it in place, hold the gear in place, and tighten the screw.

It isn't that difficult to remove the plastic carrier either, but the guide doesn't mention the difficulty in putting those springs back in place. I say you need two small screwdrivers to put them back, and a steady hand (especially the first times).

The guide also confused me a bit at first. It says to make note of the correct vertical alignment, but in fact you just put let the gear slide down.

[Da Bear]

You listen for the click sound, then you move it back again as far as you can (won't be much). Then hold it there and align as in the picture...

Tried that, didn't work.

You don't need to remove that black plastic carrier thing actually. Since the correct alignment can always be found, the gear can be lifted with the black carrier attached. It fits just barely to remove it. Then put it in place, hold the gear in place, and tighten the screw.

Probably not, but it gives more workspace removing it. Only takes 30 seconds to do so

[Phil_Bond]

It isn't that difficult to remove the plastic carrier either, but the guide doesn't mention the difficulty in putting those springs back in place. I say you need two small screwdrivers to put them back, and a steady hand (especially the first times).

I thought the springs were pretty easy to manipulate with my needle-nose pliers.

[Xious]

This is close to the truth: There are two additional alignment stages, and some drives are particularly stubborn if you ignore them. Try restoring 150 of these buggers sometime and you'll understand what I mean.  That window also differs on earlier and later drive mechanisms (there are three major variations).

I really don't have either the time, energy, health or the motivation to do FDS servicing at present, and I may decide to spill the beans on what the correct procedure is, but as I do make money restoring drives to sell, so I also lack the incentive to post my diagrams.

For what it is worth, no tool was used by Mitsumi: Gear positioning and other factors mean that you need nothing else, save the correct knowledge. 

[Da Bear]

This is close to the truth: There are two additional alignment stages, and some drives are particularly stubborn if you ignore them. Try restoring 150 of these buggers sometime and you'll understand what I mean.  That window also differs on earlier and later drive mechanisms (there are three major variations).

I fixed another FDS today and that little round hole didn't exist. Instead there was a square hole and positioning the hub using that did not work on this one. But using fredj's technique worked well.
e.g Turning the gear until you hear the 'click' and then turning it back until it stops did the trick.

[Xious]

As I said either here or elsewhere, possibly numerous times: there are several variations of the FDS mechanism, aside from the controller IC. This is one of them; there is also a major variation on the spindle hub retainer.

That's why I went through the trouble to document all of them for myself when I R-e'd the bloody thing, and made notes on all of the alignment techniques.