RF-25 Mill Z-Axis
Scale
Last updated on
Wednesday, September 15, 2010 07:44:36 PM
Eastern US Time Zone
Scales, Brackets, Scale, Cable Routing, Analog Readout
Mill DRO & X Y Axes
Scales. Mill
Tachometer & SFM
9x20 Lathe DRO X
& Z1 Axis Scale.
9x20 Lathe Tachometer & SFM
Taig Mill
Taig Mill DRO &
X Y
Z Axes Scales.
Taig CNC Mill DRO
Taig
Mill Tachometer & SFM Taig Micro
Lathe DRO
Scales
Six-inch hardened SS
scale (manual) with SPC output & M3-0.5 threads.
Trimmed some of the scale
off the top off using a cut-off wheel,
followed by a carbide end mill &
then
diamond wheel grinding.
Radius the two top corners as they are close to the on/off switch.
Brackets
Z-axis, ⅛" thick,
scale-mounting plate. The four mounting hole locations were accurately
determined using ¼-20 transfer screws. This bracket configuration allowed me to retain
use of the speed-settings plate. An earlier version used a 1/16" plate, but was
too thin.
Scale
This vertical-style scale has a good SPC plug receptacle.
This type scale was used for the
9x20 lathe scales.
Not as easy to solder on wires, though, if that is the route one is taking.
All cable plugs are
held in place with
a spot of hot glue. Soldered
a 100µF 10v tantalum capacitor across the battery leads of
the scale.
The mill's depth-stop function is retained.
Detail of the two, lower brackets.
Installed rubber washers on all scale mounts to
allow floating which reduces 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.
Radius the top scale corners by grinding with a diamond wheel.
The scale top end is free floating. Also, the
zero of the printed in/mm
scale is aligned
with the bottom edge of the transducer when the quill is fully retracted.
This scale is not a modified digital caliper but a purpose-built
vertical scale.
A similar installation was used on the
floor drill press
Z-axis DRO.
Cable Routing
Cable runs up into the belt guard housing. Button-head bolts look
nice.
The black cable is for the Z-Axis scale & the gray cable is for the
tachometer.
The cables are fastened down about every three inches along inside right side
corner of the belt housing,
then exits behind the DRO's arm mount.
The flat sides of all but two cable tie-downs, are set against the housing
inside corner so
as to not turn
under extended vibration. The arm's base is a triangular bracket
that is mounted under two of the motor hold-down bolts. The arm is made out of
1010 (1" x 1")
80/20 extruded aluminum.
I ran the cables inside the arm's back-side channel & then snapped in
black
plastic 80/20 inserts.
In retrospect, 1515 (1½"
x 1½") extrusions would have been a little stiffer.
I like to use a
Unibit
to make
nice clean holes in thin materials.
I have since removed the quill
levers.
Analog Readout
Analog readout for the mill/drill. Two-inch travel range, indicator dial. Use with the extended quill by loosening
black thumb screw, sliding down & relocking. A very low-cost option that gives excellent depth control.
Mill DRO & X Y Axes Scales. Mill Tachometer & SFM
Scales, Brackets, Scale, Cable Routing, Analog Readout
