When I took apart the table for my Bridgeport mill to clean out 30
years of crud, I had to remove the DRO's scale and inadvertantly
pulled the sender / reader apart. The reader had a springy wire with
a ball on it that held the electronics etc that actually read the
glass scale. It was easy enough to put that back together and nothing
appeared to be broken.

When I reassemble the reader and scale, what do I do to position the
sender correctly with regard to the scale? Do I just get it close
enough to read or should it ride on the glass scale? Should it touch
the glass at all? The "adjustments" are pretty crude, so I'm guessing
the little flat square reader should ride on the glass, but with the
price of these things, it's better to wait and ask first. Should I
clean the scale and sender while I have it apart? What to clean it
with - Windex? Alcohol?

RWL

On Tue, 13 Jan 2009 22:07:09 -0500, GeoLane at PTD dot NET GeoLane at
PTD dot NET wrote:

When I took apart the table for my Bridgeport mill to clean out 30
years of crud, I had to remove the DRO's scale and inadvertantly
pulled the sender / reader apart. The reader had a springy wire with
a ball on it that held the electronics etc that actually read the
glass scale. It was easy enough to put that back together and nothing
appeared to be broken.

When I reassemble the reader and scale, what do I do to position the
sender correctly with regard to the scale? Do I just get it close
enough to read or should it ride on the glass scale? Should it touch
the glass at all? The "adjustments" are pretty crude, so I'm guessing
the little flat square reader should ride on the glass, but with the
price of these things, it's better to wait and ask first. Should I
clean the scale and sender while I have it apart? What to clean it
with - Windex? Alcohol?

I think some Anilam scales have pair of machine screws in the aluminum
extrusion that don't appear to have any function other than plugging a
couple holes or fastening a label. If you remove them and position the
reader head under the holes, there are tapped holes in the head that
line up with the holes in the extrusion. With the proper screws and
spacers installed the reader head is held in alignment and you can
adjust the brackets to mate with the mounting surface of the head. The
seals should give you some idea of the proper location of the head in
the axis perpendicular to the face of the scale glass, and thus the
length of the spacers.

Take this with a grain of salt as I'm going by memory of the scales on
a BP I sold several years ago.

Alcohol is good for cleaning the glass.

--
Ned Simmons

GeoLane at PTD dot NET wrote:
When I took apart the table for my Bridgeport mill to clean out 30
years of crud, I had to remove the DRO's scale and inadvertantly
pulled the sender / reader apart. The reader had a springy wire with
a ball on it that held the electronics etc that actually read the
glass scale. It was easy enough to put that back together and nothing
appeared to be broken.

When I reassemble the reader and scale, what do I do to position the
sender correctly with regard to the scale? Do I just get it close
enough to read or should it ride on the glass scale? Should it touch
the glass at all? The "adjustments" are pretty crude, so I'm guessing
the little flat square reader should ride on the glass, but with the
price of these things, it's better to wait and ask first. Should I
clean the scale and sender while I have it apart? What to clean it
with - Windex? Alcohol?
I'm guessing this one doesn't have tiny instrument
bearings used as rollers or it would be obvious.
So, it most likely has teflon-coated pads that
ride on the glass.
The cheaper scales are built like this, and when
the pads eventually wear down due to swarf getting
past the seals, the read head starts to rub the
glass scale and wipe the grating off. Then the
scale is trash.

Examine it to see how the head is supposed to ride
on something that keeps it in close proximity to
the grating on the glass. I've never heard of onw
that was just supposed to float on the spring, I
suspect the spring is supposed to gently hold it
against the glass. But, only the sliders are
supposed to touch the glass (or something else in
the housing that serves as a slide rail).

I'd clean with alcohol, then wipe with a soft
cloth to remove any haze left behind.

Jon

On Tue, 13 Jan 2009 23:35:55 -0500, Ned Simmons
wrote:

I think some Anilam scales have pair of machine screws in the aluminum
extrusion that don't appear to have any function other than plugging a
couple holes or fastening a label. If you remove them and position the
reader head under the holes, there are tapped holes in the head that
line up with the holes in the extrusion. With the proper screws and
spacers installed the reader head is held in alignment and you can
adjust the brackets to mate with the mounting surface of the head.

Thanks. Mine does have those two screws on the scale that made me
wonder what they were for. I didn't spot the mounting holes in the
reader head that they'd mate with, but I did upload a pdf of pictures
of my Anilam scale to the dropbox.

Look for the file Anilam scale from Bridgeport milling machine.pdf

RWL

It sounds like Jon also described what my reader head may look like. I
uploaded photos in a pdf file to the drop box for anyone who cares to
look and comment on how to adjust this reader head to the scale. After
looking at my photos I'm beginning to wonder if you just put the scale
in place and adjust the mounting bracket up or down a little until the
scale reads and just tighten the screws in place. On the other hand,
scales are expensive, so I thought I'd ask the voice of experinence
before I ruined something.

Look for the file labled

Anilam scale from Bridgeport milling machine.pdf

in the drop box. I uploaded it late Wed evening.

RWL


I'm guessing this one doesn't have tiny instrument
bearings used as rollers or it would be obvious.
So, it most likely has teflon-coated pads that
ride on the glass.
The cheaper scales are built like this, and when
the pads eventually wear down due to swarf getting
past the seals, the read head starts to rub the
glass scale and wipe the grating off. Then the
scale is trash.

Examine it to see how the head is supposed to ride
on something that keeps it in close proximity to
the grating on the glass. I've never heard of onw
that was just supposed to float on the spring, I
suspect the spring is supposed to gently hold it
against the glass. But, only the sliders are
supposed to touch the glass (or something else in
the housing that serves as a slide rail).

I'd clean with alcohol, then wipe with a soft
cloth to remove any haze left behind.

Jon

I uploaded photos in a pdf file to the drop box for anyone who cares
to look and comment on how to adjust this reader head to the scale.

Look for the file labled "Anilam scale from Bridgeport milling
machine.pdf" in the drop box.

or use the tiny URL

http://tinyurl.com/8pzunw

After looking at my photos I'm beginning to wonder if you just put
the scale in place and adjust the mounting bracket up or down a little
until the scale reads and just tighten the screws in place. Does this
look familiar to anyone? Are there things to watch out for when
mounting the reader in the scale housing?


RWL

GeoLane at PTD dot NET wrote:
I uploaded photos in a pdf file to the drop box for anyone who cares
to look and comment on how to adjust this reader head to the scale.

Look for the file labled "Anilam scale from Bridgeport milling
machine.pdf" in the drop box.

or use the tiny URL

http://tinyurl.com/8pzunw

After looking at my photos I'm beginning to wonder if you just put
the scale in place and adjust the mounting bracket up or down a little
until the scale reads and just tighten the screws in place. Does this
look familiar to anyone? Are there things to watch out for when
mounting the reader in the scale housing?
The last picture tells me the read head rides on
the brown plastic piece, but it looks like the
slider pads may be worn down a bit. When they
wear down until the analyzer grating rubs on the
scale grating, the whole scale is destroyed.
This is how the cheaper scales are made, designed
to self destruct.
You might want to put a very thin strip of teflon
on the slider pads to maintain clearance between
the two glass parts. It doesn't want much
clearance, just a few thousandths of an inch.
Once that is attended to, then the spring applies
a gentle force to hold the plastic slider against
the glass. If the spacing between the two glass
parts is not tightly controlled, the scale will
not work repeatably, ie. it will lose counts when
you reverse.

Jon

On Thu, 15 Jan 2009 22:49:36 -0500, GeoLane at PTD dot NET GeoLane at
PTD dot NET wrote:


I uploaded photos in a pdf file to the drop box for anyone who cares
to look and comment on how to adjust this reader head to the scale.

Look for the file labled "Anilam scale from Bridgeport milling
machine.pdf" in the drop box.

or use the tiny URL

http://tinyurl.com/8pzunw

After looking at my photos I'm beginning to wonder if you just put
the scale in place and adjust the mounting bracket up or down a little
until the scale reads and just tighten the screws in place. Does this
look familiar to anyone? Are there things to watch out for when
mounting the reader in the scale housing?


RWL

The encoder and scale are not made by Anilam. This is a Acu-rite AR-5
model scale and encoder. The manual for the scale/encoder can be
downloaded at the Acu-rite web site. Acu-rite sold these scales to
Anilam with the custom cover plate until Anilam made a deal with RSF
Electronics to have custom scales and encoders made.

Regards,
Tim Barnard
LMSC
877-376-4373
www.digitalreadoutsystem.com

http://tinyurl.com/8pzunw


The encoder and scale are not made by Anilam. This is a Acu-rite AR-5
model scale and encoder. The manual for the scale/encoder can be
downloaded at the Acu-rite web site. Acu-rite sold these scales to
Anilam with the custom cover plate until Anilam made a deal with RSF
Electronics to have custom scales and encoders made.

Regards,
Tim Barnard
LMSC
877-376-4373
www.digitalreadoutsystem.com

Tim, thanks for that bit of information. Things are beginning to make
more sense now. I didn't realize this reader head had adjustable
standoffs. I only had time to download and scan the manual, but it
looks very helpful. I talked to "Betty" at Accu-Rite on Friday
afternoon and got some general advice. I did flick some chips off the
glass scale when I took it apart, but I want to clean the glass before
I reassemble it. Betty said they used acetone to clean scales at the
factory, but said that alcohol would work fine. The important things
she said were to use a lint free cloth and get no streaks. Getting
the scale reassembled will be next weekend's project unless something
comes up.


RWL