9x20 Lathe DRO X-axis Scale
Last updated on Tuesday, September 19, 2023 04:31:33 PM Mountain US Time Zone


Brackets, Scale, Alignment,
Cables & Mechanical Linkages


1/4-20 tapped mounting holes on the back
of the carriage & the lathe bed (not shown).

10-32 & 1 (top, center)
1/4-20 tapped mounting block.

L-channel mounted to block to hold &
protect the scale from impact/debris.

A very sturdy structure.


Six-inch, vertical style scale mounted to L-channel;
same scale style as the mill Y & Z scales.

I soldered a 100-mF 10v tantalum capacitor
across the battery leads o
f the scale

6-32 drilled & tapped (50% threads for steel)
in the cross slide table end. This particular
tap handle
has a guide that mounts into the drill press


Measured scale runout & shimmed as necessary.
The reach of the 2" dial helped.

Cables & Mechanical Linkages

Brackets & connector rods (6-32 screws) shown for the
X & Z1 axes scales. The single pivot points of the

connecting rods allow easier alignment & the round
rods do not snag debris as easily as flat surfaces. Since

the scale end brackets are slotted, the vertical adjustment
was easily achieved by moving the scale to one

end, tightening the mount nut then moving to the other
end & tightening the nut. The wires hang off the bracket

end which keeps them free to move with the carriage.
All cable plugs are held in place with a spot of hot glue.

Cross slide fully retracted showing
how all the brackets clear each other.

Installed rubber washers on the scale linkages allowing
a little floating to reduce the strain on the transducers.

The RF-25 mill's free-floating Z-axis design works
so well that now all of my mill & lathe scales

are attached at only one end while the other end
remains captured but loosened to allow floating.

This approach greatly reduces minor out of
alignment induced stress on the transducers. This

design also helps to reduce DRO jitter as does a
clean, deburred transducer with NR capacitors.

It was good that my DRO design kept the
transducers & linkage positions high, thereby providing

enough clearance & enabling me to install the 2.5"
variable speed DC motor at the lower position.

Brackets, Scale, Alignment,
Cables &
Mechanical Linkages