Microdrive Refelting with "Fix-o-moll" for Furniture

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ql_freak
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Microdrive Refelting with "Fix-o-moll" for Furniture

Postby ql_freak » Tue Jun 16, 2020 12:31 am

Refeltet my first Microdrive cartridge :-)

The cartdridge seems to work, unfortunately it could not read the stored files (EASEL 2.3). I have had used this cartridge, as I normally do not use EASEL (and of course I have XCHANGE).

For refelting I have used "fix-o-moll" "Felt gliders" for furniture (e.g. the legs of chairs). They are sold in Germany e.g. at "Obi" (under 2 EUR). See pictures below.

I did NOT remove them from the "paper" where there are melted on, but used this "paper" as the front, which presses the tape to the head. I melted the cut off felt with Pattex (a famous glue in Germany, and IMHO one of the best) to the copper spring of the cartridge, which I "cleaned" with a cardboard cutter.

When I tried to boot from it (unfortunately the keyboard membrane from the QL, which I used, is broken, so I cannot format and store files on it), it run a few minutes, and at least once the SuperBASIC boot program has had been loaded successfully. Unfortunately when loading the EASEL executable, it stopped with an error message. So I assume the mechanic is OK and the felt pad has a reliable connection.

I have ordered 2 keyboard membranes this evening. When they arrive, I will test this cartridge, i. e. will format it and try to store files on it.

To be continued...

p.s.: As you can see (the carton below the cartridge), I also own a PSION 5 mx PRO (even better operating system than QDOS!). Would be nice, if we would have a forum for the PSIONs on this site (at best separated for PSION 3 and 5 types).
Attachments
QLmdvRefelted2020061503.jpg
MDV cardtridge Detail
QLmdvRefelted2020061501.jpg
MDV cartdridge and "Fix-o-moll"


http://peter-sulzer.bplaced.net
GERMAN! QL-Download page also available in English: GETLINE§() function, UNIX-like "ls" command, improved DIY-Toolkit function EDLINE$ - All with source. AND a good Python 3 Tutorial (German) for Win/UNIX :-)
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ql_freak
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Re: Microdrive Refelting with "Fix-o-moll" for Furniture

Postby ql_freak » Thu Jun 18, 2020 8:49 pm

Keyboard membrane has arrived, but the refelted cartridge could not be formatted :-( I have tried to open it, because the tape has "looped" out, and now it's gone to heaven ;-)

Is there a way to get the tape inside, if it is looped out, without opening the cartridge (which seems not to be possible)?

BTW: The cartridges seem to be the real Quantum Leap. Albeit I'm a mechanical engineer, I have no idea how to construct and especially how to manufacture such a thing. I do not even understand, how this can work at all, as the tape goes from inner diameter about the copper spring and back to outer diameter. Normally this cannot work, as there is a difference of about 4 mm in inner and outer diameter: d*PI versus (d+4)*PI result in different circumference.


http://peter-sulzer.bplaced.net
GERMAN! QL-Download page also available in English: GETLINE§() function, UNIX-like "ls" command, improved DIY-Toolkit function EDLINE$ - All with source. AND a good Python 3 Tutorial (German) for Win/UNIX :-)
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bwinkel67
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Re: Microdrive Refelting with "Fix-o-moll" for Furniture

Postby bwinkel67 » Thu Jun 18, 2020 9:29 pm

I have had three cartridges where the tape separated and I was able to open up two and re-tape and close up again. One of the two I had put the yellow spool wheel in upside down so it wouldn't close and had to open up a second time and accidentally had the inner spool pop-out and unwind and that was not possible to fix (at that point I was so frustrated that I just unspooled the whole thing which made me feel better). The other I got back together and was able to read and write on but it wasn't very reliable. I thought maybe it was too loose and needed and extra loop and so tried that and couldn't get it back together. I still have it and will give it a go someday. A third I learned that with a bent paperclip and some tape at the end I was able to retrieve the end from the inside and then re-tape it to the other end and that one works.

I think the reason the tape separated is because back in the 90's I cut the tape that had somehow been damaged (crumpled)...i.e. I spliced out the bad part but the scotch tape I used ended up giving way after many years. Taking the plastic apart is a real pain because it's glued, so you end up breaking the end piece. Perhaps a better way is to cut the top piece right at the edge of the end piece with a sharp blade as that part isn't glued down by much and would likely come out more easily. If I need to ever open one up again, that's how I'll try.

The mechanism isn't much different form an 8-track drive and relies on the looped tape to not be too tightly wound (but being too loosely wound doesn't work well either so it's a balance). You just have to get it back into the right groves in the plastic as you put the top back. A trick I learned is to use some tape to hold the spool in place and keep it form unwinding and then gently pry it off right as you put the top back on. It takes some fiddling but it doable and I did at one point have both almost fully back together but my lack of understanding kept me form realizing that the yellow spool wheel had to be in a certain direction to accommodate a small plastic notch...if not for that I would likely still have a working rebuilt one and one waiting to be put together.



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