Re: [CAD_CAM_EDM_DRO] Dynamics research DRO

LEW BEST wrote:

> Hi
>
> I was at an auction a couple of weeks ago and got hold of a Dynamics
> Research model 750 (display) with 2 model LMT 500-19-9-0 scales. The
> display seems to be good (X, Y, Z axis readouts) but only one of the
> scales works.
>
> The scales are linear type encoders, 500 lines per inch. On the back
> they say channel A; black/white, channel B; green/black, +5v; red, and
> com; black. These correspond to the wire colors.
>
> What I was wondering was if I'd need to find other encoders to match
> these or if I could use another type, brand, etc. encoder?

Well, you really need to know a little more about the encoders. Are the
signals analog or digital? In other words, does the readout box interpolate
the signals to a higher resolution, or just display the base resolution of the
scale? Second, you need scales that match the resolution accepted by
the readout. This is pretty much standard, nowadays, and is metric.
0.0005" resolution is slightly coarser than 0.01 mm, so you can't get to
all possible values of the 1/2 thousandth resolution. Some readouts fudge
this by interpolating the flicker in the signals, others just can't get to
some readings at any position. Others use scales that have higher resolution
than 0.01 mm. Anyway, you need to find out what resolution these scales are,
or what res. the readout can accept. (There may be switches inside to set
each axis for resolution, which direction is +, and a double mode for lathe
diameter readout.)

Before giving up, you might just open up the dead scale (you can't really break
it any worse than it is now) and look for crud on the sensors, broken wires
(in the connector, too), burned out light bulbs, etc. (Really old scales had
incandescent bulbs in them, but most newer ones have IR LEDs.)

Jon

Jon

>
> I'd like (ideally) to mount 3 encoders on my mill and 2 on my lathe so I
> could plug the encoders into whichever machine I was using at the time
> if this is feasible. Thus far I've either worked the lathe or the mill
> but never "jumped back & forth" during a session.
>
> Any help appreciated!
>
> Lew
>
>
> [Non-text portions of this message have been removed]
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