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Re: Microdrives- had anyone managed to exchange the tape ?

Posted: Fri Feb 24, 2012 9:24 pm
by tofro
Every mention of Sinclair Microdrive tape spoke of "video tape". I have, however, no idea how this might or might not be different from standard audio tape - A wild guess would assume the coating should probably be of better quality on the video tape.
What I seem to recall, VHS video tape is nearly double the thickness of a standard audio compact casette (depends a bit on the recording length).
That is, you might strive for old VHS tapes ;). Make sure you don't kill any rare Kung Fu tapes, though :lol:

Cheers,
tofro

Re: Microdrives- has anyone managed to exchange the tape ?

Posted: Sat Feb 25, 2012 3:38 am
by Dave
It was a video tape base and formulation, however, there are two types of video tape: wet and dry lubricated. You cannot mix lubricant types or the video heads get dirty.

Microdrives used the wet type.

I think if you wish to cut down a donor tape, I'd recommend Panasonic HQ mastering MiniDV tapes as a compatible formulation that would work very well.

If you manage to make a suitable length and wind it appropriately and re-seal it into the cartridge *boggle* remember to join the tape with a diagonal splice.

That's all I remember.

Re: Microdrives- has anyone managed to replace the tape ?

Posted: Sat Feb 25, 2012 5:30 pm
by Dave
It's standard video splice tape.

Re: Microdrives- had anyone managed to exchange the tape ?

Posted: Sat Feb 25, 2012 7:13 pm
by vanpeebles
tofro wrote:Make sure you don't kill any rare Kung Fu tapes, though :lol:

Cheers,
tofro
I like it! :lol:

Re: Microdrives- has anyone managed to replace the tape ?

Posted: Sat Feb 25, 2012 9:12 pm
by vanpeebles
Hehehehe, maybe more like this with the ultimate computer chair


Re: Microdrives- has anyone managed to replace the tape ?

Posted: Sun Feb 26, 2012 12:26 pm
by midboss
That bloke in the first vid could be Yuen Biao. Very athletic moves!

Re: Microdrives- has anyone managed to replace the tape ?

Posted: Tue Jul 02, 2019 1:45 pm
by tcat
Hi Brane,
I had a simple scheme in mind:

- cut the original loop at head position.
- glue new tape to the end that comes from the outer end of the tape ring in the cartridge.
- pull the other end and let the glued end suck-in my new tape
- keep pulling until I pull all original tape out
- recut both ends so that they match and glue them together.
Trying to revive an old topic, I've had this in my mind, too. Any luck cutting the VHS tape?

I have sent a couple of enquiries to film making lab studios here, they are very good in cutting films across. My question was, if they could also cut a film (VHS, MiniDV), alongside.

Guess, no reply. I also went to a nearby university lab, they have a single beam laser machine. We tried to make an experimental cut, adjusting the beam power accordingly for the VHS material. Even then, the cut was not perfetcly regular.

S-O-S, any luck, ideas out there?
Tomas

Re: Microdrives- has anyone managed to replace the tape ?

Posted: Tue Jul 02, 2019 2:41 pm
by pjw
tcat wrote:S-O-S, any luck, ideas out there?
A vice, a rubber eraser, a razor blade or surgical knife. Cut the eraser into two pieces of the required thickness, jam the razor blade between the two pieces of rubber in the vice. The gap between the vice jaws must be the width of the tape to be cut. Gently draw the tape across the blade. Voila!

Re: Microdrives- has anyone managed to replace the tape ?

Posted: Tue Jul 02, 2019 4:25 pm
by tcat
Hi Per,

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.

Also, it may need a very good tape guiding from either side. Possibly, the vice can be mounted by screws right on the plastic VHS tape case. And with a bit of luck and some further adjustments, cut right inside a video recorder?

Still not sure is easilly DIY manageable.

Tomas

Re: Microdrives- has anyone managed to replace the tape ?

Posted: Tue Jul 02, 2019 7:36 pm
by Dave
I saw this process at a factory in Basildon in the early 90s. I was buying bulk custom wound to length tapes, and they were buying their tape on huge 20cm*20,000 metre rolls. (or something like that. It was a long time ago.) I went there to pick up 5,000 wound to length tapes.

The cutters are circular. They are angled very slightly apart to form a semi-circle. I believe this is so the angle of the edge is parallel between blades to not damage the tape edge. The tape is drawn across the circular cutters at about a 30 degree angle. A roller before and after the cutters holds the tape down so it can't push up over the rollers. The cut tape then plays out in a similar ark to the cutters onto individual rolls that are all turning together, driven by compressed air.

From what I recall, they said they used circular blades because the tape was very aggressive and blunted sharp edges quickly. A piece of tape run over a static blade, it will blunt in a few thousand feet. A circular blade would go for a couple of million feet.

Does anyone know the formulation and bias EQ of microdrive tape? I understand it was just dry lubricated video tape.