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

On Mon, 23 Nov 2009 02:09:23 GMT, "William R. Walsh"
m wrote:

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

That brings back nightmares of printers long gone. I won't ask why
you're fixing such an old printer.
http://www.shoplet.com/OKI62422401_Office_Supply_Okidata_microline_182_pr inters.html

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.

Ok, that's normal for an old printer. However, you're not done yet.
If you look at the ends of the head traveler, you'll probably find a
wad of accumulated crud on both sides. Use a small screwdriver or
wooden stick to remove the accumulation. You might also find crud on
both ends of the slider bar. With the power off, the head should move
VERY freely, and slightly less freely with the cartridge inserted. If
it drags with the cartridge inserted, there's some crud in the
mechanism. Oil the moving metal parts, clean the moving plastic parts
(no oil).

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.

Yep. Make sure the track teeth are cleaned with a brush. Crud in the
teeth will cause the head to skip a tooth.

While your at it, remove the head. There's a stamped metal "clip" on
a pivot holding the head in place. Release the clip and pull the head
straight up. Look at the bottom of the head and you'll see a felt
pad. That lubes the head pins. Clean the head and saturate the pad
with oil. If the plastic ping guides look warn, it's time for a new
head.

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.

Yep. Too much friction. Probably the ribbon cart.

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.)

Have no fear. The ribbon is not part of the lube system. See
previous description for removal and cleaning of the head. The real
danger of running the head like that is that the paper and ribbon
protect the patten. You can easily punch holes in the rubber patten
by printing without paper. The lever on the head assembly controls
the head position for different paper thicknesses. Pull it back away
from the patten for now. Normal is all the way forward.

Anyway, you ribbon cart is gummed up inside. Spin the knob on the
cart and see if it drags. There should be a little friction, but not
so much that you have to use force to turn the knob. New carts are
still available.

I've tried several ribbons and none of them make a difference. Two of them
are brand new, the third came with the printer.

So much for that theory. There might be some crud in the head
mechanism that adds additional friction. One odd source is the clear
plastic paper guide and thin metal thing that straddles the head.
These get covered with crud and tend to drag on the paper or patten.
When you have the head removed, also remove these and clean them. If
the diamond shaped hole in the metal shield looks mangled, try to
straighten it.

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.

The last time I saw an ML-182 was perhaps 10 years ago. As I recall,
they were not the best quality construction. The ritual repair was
the same for all such printers.... tear it apart and clean everything.

William

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Hi!

That brings back nightmares of printers long gone. *I won't ask why
you're fixing such an old printer.

Because it fulfills a need (sort of) and because I can. You didn't
ask, but now you know. :-)

It's not a big deal. I have an IBM ProPrinter XL24E with a network
adapter hanging off of the parallel port. The Okidata unit could be a
backup in case the IBM goes down (yeah, right!) or I could put
different paper in it.

I find the impact printers very handy for reasonably fast, low cost
printing of text reports. When using a draft font, they are very
quickly. I've been given boxes of suitable paper over the years, which
only drives the cost down that much further. Sometimes I still have a
need for doing two part forms, and nothing else quite comes close for
that application.

Ok, that's normal for an old printer. *However, you're not done yet.
If you look at the ends of the head traveler, you'll probably find a
wad of accumulated crud on both sides.

It's really remarkably clean. I did find some scrunched up paper and
"holes" at the edges, all of which are now gone.

The head does move freely without a cartridge installed, although it
has more resistance at each end of its travel that I think it should.
With the cartridge in place, there is more resistance. I guess I'll
have to pop it out of there and have a look to see what might be
changing to hold it up.

Yep. *Make sure the track teeth are cleaned with a brush. *Crud in the
teeth will cause the head to skip a tooth.

That track is very clean, with no obvious signs of damage or missing
teeth.

Yep. *Too much friction. *Probably the ribbon cart.

It's a brand new Dataproducts ribbon. The old Okidata ribbon only
behaves slightly differently, so I don't feel that finding an Okidata
cartridge would be a worthwhile endeavor.

Have no fear. *The ribbon is not part of the lube system. *See
previous description for removal and cleaning of the head. *The real
danger of running the head like that is that the paper and ribbon
protect the patten.

I have not printed without paper, and I did think to back the head
position out almost to the end of its travel. I will not try to print
without paper. And I will take the head out to examine it. I may also
pull the entire assembly (so long as it is not risking disaster to do
so) to see how that little motor looks and if maybe it is gummed up.

Anyway, you ribbon cart is gummed up inside. *Spin the knob on the
cart and see if it drags. *There should be a little friction, but not
so much that you have to use force to turn the knob. *New carts are
still available.

My new cartridges seem to be fine in this regard.

The last time I saw an ML-182 was perhaps 10 years ago. *As I recall,
they were not the best quality construction. *The ritual repair was
the same for all such printers.... tear it apart and clean everything.

I was always really happy with the first one I had. It was a
workhorse, although it was no IBM ProPrinter. I had to finally retire
it when the print head started to malfunction. No amount of cleaning
would help it, and eventually the missing lines got so bad that the
output was unreadable.

The only dot matrix printer I ever had that was truly awful was a
Panasonic KX-P2123. I actually bought it as a replacement for the
Okidata, but the tractor feed was so unreliable that the Okidata went
right back into use and the Panasonic went away.

William

On Mon, 23 Nov 2009 10:29:48 -0500, Meat Plow
wrote:

A new Oki ribbon cart might cure your problems. I've seen these used
in pretty crappy conditions and tolerate it well. I've serviced more
than my fair share of the 182s / 390/391/590/591 Microline/Turbo 9 pin
head printers to last several lifetimes. They are the workhorse still
for those who need an impact printer.

I'm partial to the 320/321 series of printers. I still have customers
using them to pound their way through as many as 5 part forms. Some
of these have been in service for at least 15 years. All I do is
clean them about every 6-9 months. The 9 pin heads seem to do better
and last longer than the much thinner 24 pin heads. However, I'm
constantly replacing the serial i/o board on all Oki printers, usually
due to ESD or power glitch issues. Also, people with long finger
nails tend to puncture the front panel controls.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 23/11/2009 1:09 PM, William R. Walsh wrote:
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.



--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

On 23/11/2009 1:09 PM, William R. Walsh wrote:
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.



--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------