Okidata ML-182 Carriage Troubles

[William R. Walsh]

Hello all...

I recently obtained an Okidata ML-182 impact printer in very good physical
condition. It hadn't been used in a while, and the carriage movement motor
was rather stiff. I was able to free it up easily and now the print head
seems to slide back and forth without issue. This printer is a unique design
in that the print head is not driven by a belt--the stepper motor is right
on the bottom of the print head. It runs along a toothed plastic track.

The problem has to do with this motor. With a ribbon loaded, the motor has
trouble moving the print head back and forth. More often than not, it will
stop running with the ALARM light turned on. Strangely enough, the carriage
motor will run *fine* with the ribbon removed. (I haven't run it much like
this for fear that the print head might seize up without a ribbon going
along past it, as the ribbon might lubricate the pins in the print head.)
I've tried several ribbons and none of them make a difference. Two of them
are brand new, the third came with the printer.

In years past, I had another example of the same printer. While it ran fine,
the carriage movement motor was sluggish on that printer as well. I'm hoping
that someone else has seen this and might know of a fix.

William

 

[Bob Larter]

Hello all...

I recently obtained an Okidata ML-182 impact printer in very good physical
condition.

Jeez, I haven't seen one of those in decades.

It hadn't been used in a while, and the carriage movement motor
was rather stiff. I was able to free it up easily and now the print head
seems to slide back and forth without issue. This printer is a unique design
in that the print head is not driven by a belt--the stepper motor is right
on the bottom of the print head. It runs along a toothed plastic track.

The problem has to do with this motor. With a ribbon loaded, the motor has
trouble moving the print head back and forth. More often than not, it will
stop running with the ALARM light turned on. Strangely enough, the carriage
motor will run *fine* with the ribbon removed. (I haven't run it much like
this for fear that the print head might seize up without a ribbon going
along past it, as the ribbon might lubricate the pins in the print head.)
I've tried several ribbons and none of them make a difference. Two of them
are brand new, the third came with the printer.

Try winding the ribbons by hand to verify that the ribbon moves easily &
isn't jammed up with age. Assuming that they're okay, you just need to
clean & lubricate all the moving parts on the head assembly. I recommend
a tiny squirt of WD-40 on the front & rear armature bearings of the
motor. You can 'work' the mechanism safely by turning the printer off &
moving the carriage left & right by hand. It should move freely, even
with a ribbon loaded.