Rong Fu RF-25 Mill/Drill Specifications & Views
Last updated on Thursday, December 31, 2020 06:50:40 AM Mountain US Time Zone
Original unmodified RF-25 mill configuration. The 4" vise has
been replaced by a 6" Parlec vise, DROs added, & the standard
incandescent light replaced by a high-intensity halogen lamp. The mill
is at the upper limits of weight & size that I could safely move down
a hill & into my lower-level walkout. See RF-25 Mill DRO &
X Y Z axes scales. RF-25 Mill Tachometer & SFM
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|RONG FU RF-25 MILL/DRILL SPECIFICATIONS|
|Drilling Capacity||1" (2.54cm)|
|Face Mill Capacity||2-1/2" (6.3cm)|
|End Mill Capacity||1/2" (1.3cm)|
|Spindle Nose to Table Max. Distance||15" (38cm)|
|Z - Spindle Stroke||4" (10cm)|
|Spindle Sleeve Diameter||2.44" (6cm)|
|Head Swivel||360 deg|
|Column Diameter||3.625" (9cm)|
|Overall Height (w/o Stand)||35-1/2" (90cm)|
|Machine Stand Height||30" (76cm)|
|Motor, 110v single phase||1 HP|
|Spindle Speeds @ 60 Hz||110~ 2580 RPM|
|Spindle Speeds @ 50 Hz||90 ~ 2150 RPM|
|Forward & Reverse Switch||Standard|
2-1/2" Carbide Fly
Cutter/R8-20mm Arbor, 1/2" Chuck
w/R8-J33 Arbor, 2-1/2" Angle Vise
|Y - Forward / Backward Table Travel||5.962" (15cm)|
|X - Left / Right Table Travel||14.563" (37cm)|
|Working Area of Table||23"x7-1/2" (58x19cm)|
|Volume||18.3 cubic ft (0.52 cubic meters)|
|Noise||80 dB Max|
|Gross Weight||440-lbs. (199.6-kgs)|
|Net Weight||374-lbs. (169.6-kgs)|
RF-25 mill manual.
Specifications of machines
may vary among sellers; values are approximate.
RF-25 mill table slot dimensions.
24mm = 0.945", 14mm = 0.551", & 10mm = 0.394".
Runs very smoothly & quietly. Multiple pulleys provide
ample torque & no gears to break. Drawbar nut is 17mm.
Forward (up), Stop & Reversing (down) switch.
12 speeds. Easy to change; note &
set two numbered pulley positions.
Fine Down Feed
The fine down feed housing is held to the mill with
two hex bolts. To add some backlash adjustment
to the fine down feed, the housing was removed,
the two 9mm mounting holes were opened up to about
9.5mm & the bolt heads were turned down a few
thousandths. There was also paint over spray on the
worm gear that was removed. Be sure to re-grease
the worm gear. These relaxed tolerances allowed
additional housing movement to mesh the gears much
closer & thus reducing backlash. All three axes scales
(1 division = 0.001") were verified as accurate.
Depth stop & quill lock.
1 HP, 110VAC, 60 Hz,
fully enclosed, externally cooled, motor.
Note, motor locking leaf bolt for belt adjustment &
the two, OEM 19mm (3/4") column locking nuts.Possibly due to
the OEM bolts not being hardened, they were beginning to strip.
The OEM head-locking cross bolts are a non-standard
size of 1/2-12x7 with 13/16" hex heads which makes it very hard to
find a direct replacement. A standard bolt is 1/2-13 with a smaller,
3/4" hex head which would not properly fit into the cast recess that
prevents turning. The bolt holes were already 9/16" &
did not have to be opened up so I bought hardened,
Grade 8, standard 9/16-12x7 bolts from Bolt Depot.
This size has the requisite 13/16" hex head & fit
through the holes but the bolt touched the mill's column.
I lathed the center area down to 1/2" as
well as relieving the area under the head.
The bolts fit perfectly & are now all hardened,
bolt/washer/nut assemblies. A 7/8", 12-point deep socket,
used with a long-handled 3/8" drive
ratchet work nicely. A 12-point socket engages the nut
quicker (using less wrench movement).
The best alignment is achieved by tightening the top
bolt first & then going back & forth a few times.
Halogen task light.
I used several electrical box covers to
give the magnet a good base to grip.
Installed a vibration-resistant 60W light in
the mill head's internal cavity. The large upper plastic
housing holes allow heat dissipation via convection.
The upper bracket is shown. A porcelain socket &
rotary switch were used. The AC cord is held by a cable tie down.
This is similar in function to my OEM light in the Jet floor drill press.
The bulb sticks out to give a better light
dispersion angle & good accessibility for changing.
Cutting with the halogen light
on but the built-in lamp off.
Cutting with both the
halogen & built-in lamps on.
First selected Kurt-style 4" milling vise (37-lbs.)
Used hardened bolts & washers with standard T-nuts.
Parlec 6" vise now being used on the RF-25.
Swivel base for the 4" mill vise. Remove to increase
Z distance & overall rigidity. Used only as needed.
Variable speed power table feed has high
torque throughout its range, works very well.
Clamps onto table end. An integrated travel-limit
switch is mounted on the front edge of the table.
Left/Right direction lever, variable-speed dial &
momentary extra high-speed (yellow) button.
Gear attached where original handle was located
(black plastic gear cover removed for illustration).
Power table feed operation manual.
CAUTION: Do not change power feed directions
suddenly, especially at high speeds. Move lever to
the center, neutral position & wait until motor stops.
The yellow gear cover removed.
Use graphite-based grease not silicon type.
Bottom view showing the motor engaging the
X-axis gear that replaced the left OEM mill handle.
Table travel-limit switch.
all of the quill levers so they do not
contact the piece when working close to the vise.
This configuration allows much better access
to the two column locks, belt tension lock, & DRO.
I made & installed 1/2-12 threaded aluminum
plugs to give it a finished look & keep the chips out.
I like the extra control afforded by the
fine down feed & have no need for the levers.
Vibration-absorbing machine mounts
supporting (optional) Rong Fu cabinet.