Re: [CAD_CAM_EDM_DRO] Glass scale problem

Paul wrote:

>Hi Derek
>
>I too suffered with a similar problem with the scales on my lathe. Removing
>the scale, popping the end caps off, and cleaning with alcohol & cotton buds.
>All would be fine for a while, then the thing would play up again.
>
>It would appear that cutting fluid was wicking past the seals and
>contaminating the head/glass - Not being able to get new sealing strips, I
>ended up buying a new scale. Got a reasonable deal out of the local Fagor
>sales office to boot.
>
>

I don't have a lot of experience with these, but I did observe some
pretty elaborate
procedures to keep fluids out of the Mitutoyo scales on my Sheldon Lathe.
The Z scale is on the back of the bed, under the overhang of the rear ways.
There is a wide strip of rubber that drapes over the scale, so any drips
fall
out past the scale. Ther is a 'J' shaped linkage that goes from the
rear of the
carriage, out and under the rubber, and to the scale's read head.

The X scale is mounted under a milled metal bar that forms a similar drip
shield, with a smaller version of the J linkage. It works just like the
drip
loops on wires coming into a house. the Mitutoyo scales are not well
sealed at all, just two plastic 'lips' that gently close over a tapered
slider.
But, the slot the lips are in faces down. I opened up the X scale
because it
was amazingly crudded up on the outside, but the scale and read head were
very clean, inside.

I tore apart a Teledyne/Gurley scale some time ago that had a very elaborate
closed-loop band that surrounded the entire scale, with a felt wiper at each
end of the spar.

He may need a new scale, but until the problem is understood, just replacing
the scale may not be a good idea. If the problem is a bad installation,
it will
just end up ruining another scale.

Jon