540MB MO in Fujitsu 640MB DynaMO?

[olePigeon]

@pbertolo I know the mechanism you're talking about. The bezel can be taken off, but be careful, there are two brittle clips on either end. It may just need to be cleaned. Probably dirt and grime on the hinges for the door mechanism. I seem to recall I fixed mine with a very small amount of 3-in-1 oil.

 

[pbertolo]

@pbertolo I know the mechanism you're talking about. The bezel can be taken off, but be careful, there are two brittle clips on either end. It may just need to be cleaned. Probably dirt and grime on the hinges for the door mechanism. I seem to recall I fixed mine with a very small amount of 3-in-1 oil.

Thanks for the tip! I will try and see what I can do…

 

[olePigeon]

For a temporary fix, you can manually flip the door back up if you can find something thin enough to get under the door.

 

[pbertolo]

I just gave it a quick look, the issue lays in the mechanics of the eject mechanism.
As you can see from the picture, there’s a rotating cam, which acts on a pin, translating rotational movement into linear one.
Apparently, nothing looks damaged, just kind of snapped out of position (even though there seems to be a tiny gear train that I still have to inspect, but the cam always rotates back to initial position, so it should be OK).
As is now, as the cam reaches rearmost position (270 deg), the pin just slips under the cam and the sledge is abruptly pulled back to closed position by the action of the springs.
Seems to me that by fiddling with the mechanical eject and pushing the eject button at the same time, the whole mechanism went out of synchronization.
I’d need to see a working drive for figuring out a fix…

 

[pbertolo]

Sad, short story. The loading mechanism is not OK, because there’s a broken piece.
Fatigue. Such a lousy design I could hardly believe.
It’s completely nonsensical, but as the part is almost flat, I will see if it’s possible to make a better one out of some soft metal.

 

[sunjar]

Sad, short story. The loading mechanism is not OK, because there’s a broken piece.
Fatigue. Such a lousy design I could hardly believe.
It’s completely nonsensical, but as the part is almost flat, I will see if it’s possible to make a better one out of some soft metal.

I had the exact same problem as you, I recently got an Fujitsu FN640 external MO drive, it also couldn't insert a MO disc. So how's your progress? Would it be feasible to make a similar part from sheet metal? I haven't disassembled my drive yet as I'm new to machining and would like to disassemble my MO drive and fix it if it's not too difficult.

 

[pbertolo]

I had the exact same problem as you, I recently got an Fujitsu FN640 external MO drive, it also couldn't insert a MO disc. So how's your progress? Would it be feasible to make a similar part from sheet metal? I haven't disassembled my drive yet as I'm new to machining and would like to disassemble my MO drive and fix it if it's not too difficult.

I managed to fix this piece by reinforcing it with Alu sheet (0.2 mm) and epoxy resin for keeping everything together.
The metal sheet is now bearing all the mechanical stress, the originals plastic pieces fulfil the function.
Couldn’t find a better picture, sorry.

 

[sunjar]

I managed to fix this piece by reinforcing it with Alu sheet (0.2 mm) and epoxy resin for keeping everything together.
The metal sheet is now bearing all the mechanical stress, the originals plastic pieces fulfil the function.
Couldn’t find a better picture, sorry.

Thanks for your reply. This shape looks difficult to machine. I originally considered using a thin iron sheet to achieve this shape by grinding, but now it does not seem to be easy. Your method is very clever and I plan to try it when I have time.

 

[pbertolo]

Thanks for your reply. This shape looks difficult to machine. I originally considered using a thin iron sheet to achieve this shape by grinding, but now it does not seem to be easy. Your method is very clever and I plan to try it when I have time.

Thanks. I also considered something more refined, but eventually I concluded it was not worth the effort. This solution may not look so elegant, but it’s effective. The Al sheet can be easily trimmed with basic tools, so indeed it just took me one hour of work, plus the setting time for the epoxy.

 

[Phipli]

Are these of interest?

From archive.org

Wayback Machine

web.archive.org

 

[sunjar]

Are these of interest?

From archive.org

Wayback Machine

web.archive.org

Cool! Very good information.

 

[tt]

I posted an image of the CDROM that came with the external SCSI 640MB DynaMO drive here: https://www.prismnet.com/~trag/Mac_Drivers/

The disk is imaged using Apple Disk Copy 6.3.3. I think Anarchie must have added the .bin. So it looks like you might need software to de-binhex it and then Disk Copy to mount the image. When it's all uncompressed, it's only about 50MB.

Was a copy of this CD image backed up somewhere?

 

[trag]

Was a copy of this CD image backed up somewhere?

All of my content formerly at prismnet.com/~trag is now at sphinxgroup.org. Do not add the ~trag at the end. tigertech handles web space a little differently from how prismnet did.

 

[tt]

@trag I was able to find it, thanks!