Metal square over 3.5" drive head fell off, is it required?

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Metal square over 3.5" drive head fell off, is it required?

I opened up the 3.5" floppy drive from my IIgs to retrobright the case and two small metal squares with numbers printed on them fell out. Checking pictures the drive, it looks like it was glued right above the head. The top I can access, I assume on the bottom you have the tear the drive down completely. Not sure what these do, if it's ok to just leave them off?

 

 

 

 

 

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I would glue them back.

I would glue them back.

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shields

I believe those are mu-metal to provide magnetic shielding for the heads. I have seen them fall off as well.

It should be straightforward to glue them in using a drop of CA adhesive.

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Thanks, I'll super glue the

Thanks, I'll super glue the top one back on, bottom one looks like have to take it all apart and probably mess up the alignment or something

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jasonnovak wrote:Thanks, I'll
jasonnovak wrote:

Thanks, I'll super glue the top one back on, bottom one looks like have to take it all apart and probably mess up the alignment or something

Difficult to perturb the alignment on these drives unless you mess with the position of the stepper motor on the end.  You can easily remove the read-write sled and access the bottom of it.

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Do you have any hints on what

Do you have any hints on what screws I'd need to remove? I  tried checking a service manual and it just showed basic disassembly, and there are lots of videos on youtube cleaning the heads, or replaced broken eject gears, but I don't see anything that would help. I found this picture with a good view of the heads

 

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This video shows removing the

This video shows removing the sled around 47 minutes. The 800k drive chassis in macs are the same as the IIgs. You will also want to clean and regrease the eject mechanism if you haven't. And replace the eject gear. If it hasn't disintegrated yet, it will.  

https://m.youtube.com/watch?v=sy6JWEerHQc

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thanks, looks like just what

thanks, looks like just what I need

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I ended up ordering the 

I ended up ordering the  lubricants recommended in that video too, had been  wondering for a while what I should use, and some  gears, what started out as just gluing some metal back on...

 

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I'm not a fan of using the

I'm not a fan of using the super lube he shows in this video. Especially when he talks about having to thining it out with oil. He does mention molykote em30l though. That's actually what I use and would recommend. I'm also not a fan of his recommendation to use wd40 as a cleaner. Just stick to 99% ipa. 

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agreed

Agreed, although using only isopropyl will make technical cleaning more challenging. It helps to have a wide range of solvents/degreasers on hand to deal with different types of soils. The least amount of labor is to use a vapor degreaser or ultrasonic bath.

A NLGI 2 grease is a bit too thick for this application. NLGI 1 would be ideal. Higher viscosities are needed in gearboxes under higher loads to prevent grease from being flung away from the gear teeth, so something like Super Lube might be appropriate for the gear teeth in the eject motor assembly (which are not lubricated at all in the video). But a molybdenum disulfide grease would likely perform better for that.

A point that is sometimes missed is that many 3.5" drives have SMD electrolyic capacitors which are becoming one of the most common reasons for failure.

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Can't speak to third party

Can't speak to third party drives, but the Apple 800k (and 400k) drives don't use SMD electrolytic. They use radials. I can't say that out of the seven 800k and two 400k (which those eject mechanisms are a pain to service compared to the 800k) I have worked on, I haven't seen any signs of leakage when I cleaned/greased/recapped them. But at least now I know they will out live me. 

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I've decided to just go with
I've decided to just go with white lithium grease then, seems like what most people use and was easy to get, and I'll use the oil for the rod. I was able to remove the heads without issue, though I see I was wrong the 2nd metal plate goes on the bottom. I have no idea now where it went, I see a little glue residue on the back of it, but don't see any glue where it may have been sticking. Looking at other videos I can't see another spot where it might have gone - my only thought is the two plates were both glued to the top of the head (though it's flush with just one). Pics from my actual drive
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That prompted me to tear one

That prompted me to tear one of these drives apart, and there's no plate on the bottom of my head either.  In fact I can't see where that second square might have come from.

 

 

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I mainly opened it up  to

I mainly opened it up  to retrobright it, I didn't really recall hearing anything rattling around. Now that I have it open I'm going to relube things and change that eject gear, mine drive is ok but sounds like it likely will. I'll just leave the second one out

 

 

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Just to follow up put

Just to follow up put everything back together, re-lubbed the drive and replaced the eject gear, at first I though I messed it up since wouldn't eject, but mine had a  screw-on plate over the gears and was overtightend, loosened  them and it worked. The covered in the  videos seem to be clipped on.

 

 

 

 

 

 

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