Tapped 50% threaded NC ¼-20 mounting holes at end of table.
It is difficult to cut fine threads in cast iron due to crumbling.
RF-25 Mill DRO Y-axis
Scale
Last updated on
Wednesday, November 21, 2012 05:24:48 AM
Eastern US Time Zone
Scale Brackets, Scale, Lower Brackets, Cables, Handle Animations
Scale Brackets
Tapped
50% threaded NC ¼-20 mounting holes
at end of table.
It is difficult to cut fine threads in cast iron due to crumbling.
¼" thick upper bracket must
clear lead-screw bearing bracket housing.
Semi-circular relief is stronger than a rectangular alternative.
L-channel bracket with scale mounting bolts. L-channel
bracket must clear power-feed motor.
The L-channel serves as the scale mount & protects it from impact, fluid & debris.
Six inch vertical-style scale mounted. All sharp corners have
since been rounded.
I have installed rubber washers on all the scale mounts
to
allow a little floating to reduce the strain on the transducers.
Scale
This is the first scale I ordered for the Y-axis. The catalog picture
& description
did not match what I received.
This 6" horizontal-style was smaller &
does not have as good of a
receptacle (for me) as the vertical style.
If you have space limitations and/or are tacking-on wires,
you may want this style.
Instead,
I used this style on
the Taig lathe DRO.
The
better receptacle (for my needs) is shown on the
Z-axis scale page.
I solder a 100µF 10v tantalum
capacitor across the battery leads of the scale.
Lower Brackets
Lower bracket mounted using
¼-20 bolts. This mill base side is 5º.
Tapped holes are perpendicular to the mill base surface.
Lower bracket detail.
Bolt
clearance holes perpendicular to both front & back 5º surfaces.
The rear holes are horizontally centered on the bracket.
Cables
¼" thick connecting bracket uses M3-.5 upper bolts &
8-32 lower bolts.
This mount
protects scale's front (which is not needed) &
places the SPC output on the bottom, back, left.
Only hardened SS scale surfaces are exposed.
This style scale has a good SPC plug receptacle.
Cable is protected with spiral wrap & has nylon ties for
strain relief.
X-axis & Y-axis cables are (directly)
routed under the mill inside the stand
allowing me to use the standard 6 ft. SPC cables.
All cable plugs
are held in place with a spot of hot glue.
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, deburred transducer
with NR capacitors.
Handle
Animations
Revolving, chrome plated carbon
steel handle, animation.
Left: OEM plastic handle table locking levers interfered with
DRO brackets.
Right: Replacement zinc alloy/steel locking adjustable levers.
Animation of the replacement
locking levers for the carriage.
Kipp (USA) adjustable handle (ball style) 5/16-18 with a 2.36"
(60mm) long threaded stud.
Levers now more accessible, clamp much tighter, clear base & are away from the lead screw.
Scale Brackets, Scale, Lower Brackets, Cables, Handle Animations