Does anybody here have any experience with the Eason ES-8 DRO?
We have one on a lathe in the museum workshop where I volunteer restoring
old machinery such as steam traction engines and similar stuff. We have a
relatively new(18 months) lathe with the Eason DRO on it. I'm having a bit
of trouble with it and, as I'm not to familiar with DRO's, don't know
whether I'm expecting too much from it or if there is something wrong with
it. I take an initial cut with the lathe, then measure the diameter of the
work and set it into the DRO and hit enter. I then put the next cut and turn
on the motor. The reading immediately changes and dances around by a few
hundreds of a millemeter or thou. After taking the cut on the work, I
measure it and find that it is off by as much as 7 hundredths of a
millimeter from what the DRO says it should be.

Am I doing something wrong, is ther a fault in the DRO, or am I just
expecting too much from what is a relatively cheap devise?

Any ideas would be appreciated.

"Grumpy" wrote in message
news
Does anybody here have any experience with the Eason ES-8 DRO?
We have one on a lathe in the museum workshop where I volunteer restoring
old machinery such as steam traction engines and similar stuff. We have a
relatively new(18 months) lathe with the Eason DRO on it. I'm having a bit
of trouble with it and, as I'm not to familiar with DRO's, don't know
whether I'm expecting too much from it or if there is something wrong with
it. I take an initial cut with the lathe, then measure the diameter of the
work and set it into the DRO and hit enter. I then put the next cut and
turn on the motor. The reading immediately changes and dances around by a
few hundreds of a millemeter or thou. After taking the cut on the work, I
measure it and find that it is off by as much as 7 hundredths of a
millimeter from what the DRO says it should be.

Am I doing something wrong, is ther a fault in the DRO, or am I just
expecting too much from what is a relatively cheap devise?

Any ideas would be appreciated.


I am not an expert machinist, but I see no one else is responding. Have you
considered there may be some slop or stiffness issues in the cross slide?
For example, if the cross slide pivots due to cutting forces, the cutting
tool may move back while the glass scale on the other side moves forwards.
If the stiffness issues can't be corrected, you may be able to live with
them by taking the same depth of cut before setting the DRO and when making
the last cut. Also make sure you always set and read the DRO with the same
force on the tool.

The reading immediately changes and dances around by a
few hundreds of a millemeter or thou. After taking the cut on the
work, I measure it and find that it is off by as much as 7 hundredths
of a millimeter from what the DRO says it should be.


The Eason DROs are similar (almost identical, really) to the East Indian
DRO (DRO-Pros) I selected for my lathe.

They make a big point of two things: One, everything must be properly
grounded, and that includes using the bonding braid that comes with the
kit to ensure the display head is grounded to the lathe chassis, and Two,
the clearance to the scales on the pickup heads is crucial. They supply
a shim to set the clearance, and it must be pretty much nuts-on.

Some of the optical scales have no adjustment, but all of the magnetic
ones do.

I consistently do work to two-tenths on mine. I even found a bit of gib
play with the DRO as a reference.

LLoyd

On 2012-03-07, Grumpy wrote:
Does anybody here have any experience with the Eason ES-8 DRO?
We have one on a lathe in the museum workshop where I volunteer restoring
old machinery such as steam traction engines and similar stuff. We have a
relatively new(18 months) lathe with the Eason DRO on it. I'm having a bit
of trouble with it and, as I'm not to familiar with DRO's, don't know
whether I'm expecting too much from it or if there is something wrong with
it. I take an initial cut with the lathe, then measure the diameter of the
work and set it into the DRO and hit enter. I then put the next cut and turn
on the motor. The reading immediately changes and dances around by a few
hundreds of a millemeter or thou. After taking the cut on the work, I
measure it and find that it is off by as much as 7 hundredths of a
millimeter from what the DRO says it should be.

Looks to be spelled Easson (two 's's) according to a Google
search.

Hmm ... turning on the motor changes the reading without moving
the dial? Is there another readout for the longitudinal position? If
so, does that change at the same time?

If there is a second readout, and no change on that, what
happens if you swap the connectors from the two scales? Does the jump
follow the cross-feed scale, or does it stay in the particular readout?

How much backlash is in the cross-feed leadscrew? What the DRO
can tell you is where the cross-feed is -- and if there is backlash, the
cross-feed can move without any change in the dial's reading. (A
relatively new lathe should not have such problems, but it may -- or
even the gibs may not be tight enough.

Anyway -- set up a dial indicator and check whether the
cross-slide moves when you start a cut. If so -- there it too much slop
somewhere.

Note that usually DROs for lathes have a switch for the
crossfeed to either read radial motion, or diameter of material to be
removed (radial multiplied by two). If it is in the wrong position, you
get significant errors. (Some lathe feed dials are designed to read in
diameter changes and others (all that I have) read in radius changes.

Looking at a PDF file downloaded from a Google hit, it is
apparently the 1/2 button. Hmm ... no it is for centering.

Also -- is the DRO powered from the same outlet as the lathe?
If so, what happens if you move it to another outlet.

Also -- check whether either the ends of the scale, or the
pickup head are loose in their mounting to the lathe.

Am I doing something wrong, is ther a fault in the DRO, or am I just
expecting too much from what is a relatively cheap devise?

Any ideas would be appreciated.

Some things above to check.

Good Luck,
DoN.

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