#2083

[@benjaminhanke79]

05:50 "just cut him off" 😮 Nooooo! Please no unnecessary destruction.

[@CraigHollabaugh]

Who's kidding who Mr. Phelps, that tape will self destruct in 5 seconds.

[@pauluzs]

Since the kepton tape is driving the magnetic tape on the outside, the speed of both tapes would be constant across the read heads. Only the reel speed changes with diameter and the tape speeds are directly related to motor rpm

[@uni-byte]

Yes, this is correct.

[@TheEmbeddedHobbyist]

My problem in thinking is the drive tape goes around both spools and run on the tape. the diameter of the tape changes as the spools empty and fill, but if the drive tape is going to be rubbing on them. so it's going to pull the tape off one spool at the same speed as it pulls the tape on the other regardless of tape diameter on each spool. I expect the tape will be moving quite slow as it might have to record for more than one flight. but then again is it com's or instrument and flight controls data.

[@svofski]

this is similar to how it's done in QIC cartridges, except that they use rubber and they're giving people headaches when the rubber perishes

[@NinerFourWhiskey]

It is a data recorder (tape cartridge system) qualified for non-pressurized operation (not sure how how). I've not seen this particular one. The coating is almost certainly chromate conversion (alodine) common in aviation/military gear.

[@uni-byte]

It won't speed up. The driven Mylar tape is in contact with the magnetic tape therefore the mag tape will travel at the same speed as the Mylar tape. The spools will change speed though. The tachometer is there to keep the drive speed CONSTANT. It's actually quite ingenious.

[@johnwest7993]

When I was a kid my parents always asked me why I took everything apart. I told them it was to see how they worked. It seemed obvious to me why I took things apart. It never occurred to me that there were people who weren't totally curious how things worked.

[@universeisundernoobligatio3283]

Always said if they did not want you to take it apart, why did they put screws in it?

[@EZgoing14901]

I was very much the same...

[@M0UAW_IO83]

I have no idea what I'd use it for but I love this piece of tech, the mechanics of it, the appearance, it's just great.

[@frankowalker4662]

You had that running way too fast in the forward direction. If it's a voice recorder, I'd expect it to run at 1 7/8 i.p.s. (cassette speed) or even 15/16 i.p.s. (1/2 cassette speed)

[@cedarmyers6709]

Interesting how we assume we know what the forward and backward directions are. Can't wait to see some signals from the tape!

[@milantrcka121]

DC motors, especially this type, are quite stable while used with constant voltage supply. I would run the speed quite low (as mentioned below), monitor the speed using the tach pickup. Looking forward to the next installment. Expecting a simple integrating amplifier...

[@MrMersh-ts7jl]

Its a great solution to tension the tape without a capstan. Simple and elegant. Id guess tape speed is 1 and 3/4?

[@IgorM-n1j]

Simply put couple of volts on the motor and look at the outputs of the heads with your scope :)

[@davematthews7686]

The greenish color might be Alodine. It is used as corrosion prevention for aluminum parts in airplanes.

[@hughgilbert390]

Alodine (iridite?) is also electrically conductive where anodize is not.

[@byronwatkins2565]

The spindle drives the tape rather than the reels. The reels just go at the tape speed; but, they do speed up as the tape is depleted (and slow down as the reel fills). I am surprised that the filling reel does not become loose and hamper reliability. Often we use a slipping elastic cord over the drive wheel to remove slack. Anodizing grows an amorphous aluminum oxide layer. Without dye, this is transparent (or white if it grows quickly and thick); but, they can dye it any color they like.

[@JanEringa8k]

Computer tapes (Qwik, DAT & I think DLT) used a similar "band" around the tape reels to keep the speed constant

[@Dennis-uc2gm]

I bet that mechanism wasn't cheap back went it was considered current technology.

[@mr1enrollment]

I imagine that the read/write speed is neighborhood of 1inch/sec or even less. Actually don't know - but since these are meant to be flight recorders - they must provide an extended time. Careful with your screw drivers if they are magnetic - keep away from heads unless you have a de-mag. Interesting drive,...

[@benjaminhanke79]

1.75 Inch per second, half or even quarter of that.

[@MaxPivovarov]

yellow colour is wash primer (acid etching primer base on phosphoric acid).

[@TomSherwood-z5l]

Wonder what the rest of the thing looks like. So it is just the mechanicals of a full recorder system and is made removable for maintenance and possible data retrieval in a shop. I am surprised that motor whizzed at 5 volts as alot of those type of motors run on 28V in aircraft stuff. There is often the part numbers, maker, rated voltage and RPMs etc. printed on those kind of motors.

[@Hellhound604]

One thing I still find weird… in the 1980’s we had to exchange all mylar/kapton tape in the avionics equipment I worked on… google give some excellent links about it… yet somehow it made a huge return… nowadays I see it all over again. did they change the formula, or was it hysterics that some of the avionics industry picked on????

[@sefarkas0]

The coating looks like Chromate conversion coating, pretty common in the 70s

[@JamieTyson]

Could be the hexavalent zinc! Nasty stuff to use, but worked so well you could brush it on repaired aluminum on the runway! Lots of good US Navy and Air Force docs on this.

[@silentrunner3067]

possibly chromic acid dip, or if I recall correctly conversion coating spec # MIL-P-8514 wash primer

[@silentrunner3067]

correction MIL-C-8514

[@WolfmanDude]

Wow that mylar belt drive system is kind of genius. I think it automatically corrects for the changing diameters of the reels, keeping the tape speed (ft/s) locked to the motor RPM. Super reliable with minimal moving parts compared to capstan and pinch roller. Also I think you are running it way too fast :D

[@zaprodk]

Lots of aircraft body panels have this yellow anodising.

[@TeslaTales59]

Are you going to reassemble and play the tape on an audio device?

[@TomSherwood-z5l]

Unless it is a data recorder which would be inaccessible for anything. Just to see if it is recorded on is all.

[@BrendaEM]

Warning: do not under any circumstances even look at a Nagra SN vintage recorder.

[@IMSAIGuy]

Too late.

[@BrendaEM]

@@IMSAIGuy , am terribly sorry. : ( So nicely made; so painfully expensive. Duplicates could be made, if one was in hand to to draw out in CAD...

[@MaxPivovarov]

Do you have enough knowledge to get this working and find out what’s recorded on the magnetic tape?

[@TomSherwood-z5l]

You might experience the big mil surplus letdown when you have a particularly nicely made, superb quality device that you can find absolutely no use for at all. If you get frustrated you can pass it on over to Fran Lab or something and move on.

[@chronicfatigue5416]

Make a tape delay out of it and sell it to a guitar player. If you don't, send it to me and I will.

[@robertw1871]

Looks expensive, can’t buy things like that anymore

[@IMSAIGuy]

The military did then, and the military do now

[@TheElectronicDilettante]

I can’t imagine that if it was holding classified data, that it would have the ability to play the data built in. Maybe throw the tape on a reel to reel audio player, or transfer into an old plastic cassette and stick into a data tape reader circa War Games.

[@TomSherwood-z5l]

The only classified thing is that it was recording military flights, not that there was any super secrets on tape.

[@KeritechElectronics]

A thing of beauty, a joy for ever.

[@Mr.Leeroy]

Duralumin?

[@haraldlonn898]

Slow, very slow.