Microdrives- has anyone managed to replace the tape ?

[pjw]

Good idea. I was also thinking to put as many razors 1,9mm appart, as fit across VHS tape width, but then it would reuquire a lot more force to pull tape through the blades.

Just remember to change the blades every few thousand feet

[bwinkel67]

So microcassettes are 3.81 mm wide (same as standard compact cassettes) and microdrives are around 1/16 of an inch which is about 1.6 mm wide. So watching Techmoan the other day I saw this:

https://www.youtube.com/watch?v=t5FqjQlFBDM

Picocassettes are thinner than microcassettes. I haven't found a spec for them yet online but at 1:45 in the video you can see that it's about half the size of a microcassette (at 3.81 mm). So that comes to 1.9 mm for the picocassette. The "half size" is just eyeballing it so it may be close to or exactly 1.6 mm. Quality of tape I don't know and the picocassetts are also hard to come by, though one seller on eBay has more than 10 at $8.95/each currently (which includes shipping). One tape holds 30 minutes per side and the tape speed is 9 mm/sec which comes out to be 16,200 mm of tape length which is 53 feet of tape. I took a microdrive apart recently because the tape broke and I lost one end of it but don't recall how many feet it is though it wasn't close to that.

At 7.25 he talks about the Sony NT which is a higher quality digital tape but it is thicker at 2.5 mm (there is a spec for it). Even though it looks the same size you can see that its a tiny bit thicker in the case (or the picocassette maybe had more blank area in its width).

So, an analog cassette, would that work? I know the microdrives used a quality of tape similar to video recording tapes but it would be an inexpensive thing to try and spool one of these at the right length onto a microdrive and see what you got. I think Mattel used to have a video recorder that recorded on compact cassette which didn't work well but could still capture grainy black and wide video and sound so maybe the quality of the tape could work. Still, at $8.95 it might be worth a try as I do have an open cassette with the tape pulled out (and spooled on a paper roll presently).

[Chr$]

I've actually got some original cartridges that were written to once, then never sold and have been sitting around all this time. Once I've replaced the felt piece they seem pretty damn reliable.

[tofro]

I've actually got some original cartridges that were written to once, then never sold and have been sitting around all this time. Once I've replaced the felt piece they seem pretty damn reliable.

The problem with the cartridges actually seems to be not so much the tape, but rather the felts. If you don't mechanically destroy the tape and the felt is OK (thus, not causing the former), the tape can last virtually forever (expressed in relative terms ).

Tobias

[Chr$]

I've actually got some original cartridges that were written to once, then never sold and have been sitting around all this time. Once I've replaced the felt piece they seem pretty damn reliable.

The problem with the cartridges actually seems to be not so much the tape, but rather the felts. If you don't mechanically destroy the tape and the felt is OK (thus, not causing the former), the tape can last virtually forever (expressed in relative terms ).

Tobias

Yes, when you have a 'good' one, i.e. one that was looked after and where the felt was replaced before it could do any damage, they seem to be generally ok. I do find some used ones that don't behave though and I think if they have seen a huge amount of use they are less likely to be reliable.

[tcat]

Yes, I agree.

If it were reel to reel media, tape does not wear that much, in my opinion. The only wear it incurs is that sliding over the heads.

EDIT rephrasing for clarity, need help to get better wording...

Microdrive's tape is spooled on a single reel. With tape coming in the outer bigger diameter, spiraling towards the middle of a smaller diameter, the individual layers of tape on the spool rub against each other to overcome the circumpherent difference. The angular velocity is bigger towards the middle and is slowest on the outside. The tape is tightening up around inner threads, while loosening on the outer ones. Could this `rubbing' be significant, causing an extra wear in addition to the normal contact with the head? Also the tape lube is diminishing over the years probably, which may be putting a limit on the lifespan of the tape.

Tom