T100 (USTTY) Prints rubbish when tape punch running

[M1ECY]

Having some interesting issues with the USTTY T100.

Normal receiving and local printing work perfectly - both on I-Telex and in Local mode with T56 FSG - Also prints fine on Line Current test box.

When the punch is switched on I get "Alphabetti Spaghetti" this happens under all test conditions.

I have thoroughly cleaned every part of the machine, lubricated everything generously, I have also set the motor speed witht the tuning fork whilst depressing the "Run Out" lever as per the service manual instructions.

Having exhausted all of the ideas to solve this problem, time for the experts to help

Any clues where I should look next?

Cheers
Sean

[wyssby]

Hi Sean,
if I understand you right, everything works fine unless you turn the PUNCHER to on.
For this purpose it's just the punching mechanics that will be engaged and nothing will be changed to the line loop.

In contrast, sending a punched tape works fine? This would require its sender switched in line to the line current and therefore could disturb the signals - and also could interfere with the mechanics of the machine.

Sorry but I can't remember anything, that might cause this effect when just turning the puncher on (mechanically). There should nothing be touched at the electrical parts by this, or does your machine has some strange extensions ? The puncher alone runs freely if you turn it by hand?

Regards Beat

[M1ECY]

Hi Beat,

Yes, this is correct, the machine works perfectly without the punch running, with the punch switched on, the printer prints rubbish, but it looks like the output from the punch is sensible.

Tape reader works fine.

Understand that the punch is a purely mechanical connection, and yes, punch mechanics run freely by hand.

[wyssby]

I remember two things that gave me a hard time with the T100 puncher:
- The levers from the puncher modul touching the "signal bars" to receive the code
- The small axle that ends with the round plate connecting to get the rotation power
It is important, that the levers are to the right position (left-right) and also in right high in regards the bars, not blocking those.
Also the axle should connect fine, but not push (to) hard to the counterpart, this might interfere with its rotation and slow it down.

[M1ECY]

Back again, after more investigation and substitution of other spare parts.....

Problem is solved, and may have been caused by me.

Explanation:

The drive shaft for the tape punch is driven from the end of the printer camshaft - this is a two piece coupling, with a securung screw to allow for the shaft to be installed after the punch and printer are fixed in place.

However, with this arrangement, it is very easy to install this shaft so that the punch camshaft is 180 Degrees out of phase with the printer punch - the tell tale is that the printer end of this shaft has a drive dog that should align with the "Dog Clutch" on the punch.

So, probably a maintenance induced fault.

Cheers
Sean