9x20 Lathe Z1-Axis DRO Scale

Bracket, Alignment, Mechanical Linkages & Cables, Low-cost Z1-Axis Travel Dial

9x20 Lathe DRO & X Axis Scale.  9x20 Lathe Tachometer & SFM
RF-25 Mill DRO & X Y Z Axes Scales. RF-25 Mill Tachometer & SFM

Taig Mill  Taig Mill DRO & X Y Z Axes Scales
Taig CNC Mill DRO  Taig Mill Tachometer & SFM  Taig Micro Lathe DRO

Bracket

L-channel bracket mounts on the back of lathe bed to hold & protect the Z1-axis scale.
The 10-32 bolt to the far right is for mounting the electronic scale bracket.
The bed is cast & therefore, uneven. To enable adjustment for this, I placed jack screws below
each of the three, ¼-20 mounting bolts & then used a 2" dial readout to iteratively
adjust the entire 26" long bracket until it was even in both dimensions. Due to the inside
corner radius, the bracket was spot milled to flatten the 3 areas under the hex bolt heads.
The reach of the 2" dial readout allowed me to measure the entire length & depth of the Z1-scale bracket run out.
I used self-centering spherical & shim washers to aid alignment.

Of all the DRO scale mountings, this one was the hardest to mount & align due to the lathe's uneven, cast base surface.

Alignment
 align

An old X axis L-bracket shown.


Measured scale run out & shimmed as necessary.

Mechanical Linkages & Cables

X & Z1 axes scale linkages. New X axis L-bracket now matches the overall design.
Transfer screws, both imperial & metric, were essential for accurate hole placements.
I soldered a 100µF 10v tantalum capacitor across the battery leads of the scale.
All cable plugs are held in place with a spot of hot glue.


Installed rubber washers on all the scale mounts which allows a little floating to reduce 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 transducer. This
design also helps to reduce DRO jitter as does a clean, de-burred transducer with NR capacitors.


Everything shown here, the X scale & Z1 linkage bracket, is
mounted to a single block that is attached to the back of the carriage.
The single pivot point of the connecting rod allows easier final alignment.

Low-cost Z1-Axis Travel Dial

Before the lathe DRO, I sometimes used a dial indicator with 2" travel range mounted to the back rail
by a Mighty Mag magnet. Use gage blocks to get longer distances.  A DRO is a better solution.

9x20 Lathe DRO & X Axis Scale.  9x20 Lathe Tachometer & SFM

Bracket, Alignment, Mechanical Linkages & Cables, Low-cost Z1-Axis Travel Dial