Rong Fu RF-25 Mill/Drill Specifications & Views
Last updated on Friday, November 01, 2019 09:31:22 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 The 4" vise has been replaced by a 6" Parlec vise, DROs added, & the standard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 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
More books on machining.
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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)|
Rong Fu RF-25 mill manual. Specifications of machines may vary among sellers; values are approximate.
RF-25 mill table slot dimensions where: 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, single-phase, 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
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.