DEC H605E

[Tony Duell]

>  William> SO that is the original DECwriter then. I do not know if
>  William> anyone on the list has an LA30 (they are pretty rare,
>  William> apparently), ...
> 
> Probably because they tended to jam a lot.  I remember we had one in
> college and scrapped it as soon as we could.  All subsequent
> DECwriters were excellent.

That is not the adjective I'd use to describe the LA36 :-)

The LA36 has a really nasty bit of design. There's no home switch for the 
carriage. Instead, it rams the carriage into the end stop and detects 
that the motor is not turning (no pulses from the position encoder). Fine 
until the plastic key moulded into the sprocket breaks. The motor keeps 
on turning with the sproket slipping on the spindle and draws enough 
current to burn the enamel off the windings. It then goes short-circuit 
and blows the motor fuse.

About 10 years ago, this happend at the place where I was studying. DEC 
could still supply the motor, but at the ridiculous price of \pounds 130+ 
(this is a simple permanent-magnet motor). On the ground that research 
student's time is not worth that much, a friend and I stripped it down 
and rewound it. It ran find for another 2 years.

We finally scrapped that machine. I didn't want it, but I saved most of 
the useful bits, including all the PCBs, the printhead, etc. I still have 
that motor with the handwritten label 'rewound by ARD and AMG' somewhere.

-tony