IH Bedmill vs Square Column Mill Drill
IH CNC's Manual Mill Comparison
A few facts to show the common mistake being made of comparing an
IH 12Z Bedmill to an RF45 Mill Drill
In 2003 we began the project to redesign the Square Column Mill/Drill.
Our CNC kits were limited by what an RF45 would support.
We needed a base mill that could handle all the speed and
side loading our Full Servo CNC System can generate. Not a
clone nor a copy, but a fully designed and engineered Heavy
Duty piece of machinery.
We believe that we have achieved what we were after: a mill
that is a great manual mill with a DRO or as a full servo
CNC mill capable of 12-hour days of hard production.
Although inexpensive mill drills are great and have their
place in the shop, they just are not up to the task of
being the base mill for our Turnkey CNC Mill Systems
(which have to perform to a much higher standard).
Key Problems with RF45 Mills/Drills, Whether Square or Round Column
- Small Travel (7.5" x 21" And Less)
- Low Rigidity limits Speed & Feeds
- Soft Drive Gears
- Poorly Finished Ways
- Undersized Castings
Early IH Mill with 10” Slide
This is a picture of #2 of the first IH Mills that we still have.
We also have #1 (CNC'd) and use them both.
- 9.5" x 40” Table
- 12" x 30” x 22" Machine Travel
- 2hp Motor
- Hardened Gears
- Superior Lead Screws
- Weight: Approximately 1000 lbs
Machine castings were completely redesigned for this Mill.
Substantial amounts of ribbing and reinforcement points were
The column is now 8 inches wide with a thicker casting and 5
reinforcement points. The slide is now 10 inches versus 7”
on an RF45. This machine was a vast improvement over an RF45
Mill Drill. Over 250 lbs more of reinforced casting than the
average RF45. Early models still had milled ways not yet
ground and a noisy head.
New IH Manual Mill 12.5” Slide & Collar
While the Head Slide & Collar are the major visible differences
between these 2 IH Mills, there have been substantial changes.
Today’s IH Mill is in fact competitive or superior to similarly
sized Knee Mills in power and rigidity. The ways are now ground, fit
& finish is great, and lead screw dials are accurate to tenths.
The new head is also much quieter.
The ability of a Milling Machine to effectively transmit power is
primarily limited by Head attachment and Column support to it&rsqo;s
base. Increase those two factors and you are able to effectively
use more power. An RF45 head slide attachment is 7” high and
weighs 14.5 lbs. The IH Mill head slide attachment is 12.5 inches
high and weighs 45 lbs. The slide assembly is attached to a wider,
heavier, and significantly more reinforced column, which in turn is
attached to a much larger base with four reinforcing points. It now
has nearly 300 lbs more reinforced castings over the average RF45.
Note: we are using Rigidity to express what
happens when a machine surpasses its point of effective power
transmission. Noise, vibration, and cutter shake can be increased,
when this occurs, possibly to extreme levels.
A 40 inch Table with 12” x 30” of travel!
A normal RF45 has 7.5” x 21” travel, for a total of
158 sq. inches of machining area. In contrast, the IH Mill has
360 sq inches: more than twice as much! The RF45 32” table
is shown on the left, with a table-mounted Mini-Mill on the right.
The IH Mill still has a small footprint, and can be placed
in garages and even basements.
The first thing you’re going to notice when you turn on an
IH Mill is how quiet it is! The reason why an IH Mill is so much
quieter is a precision-cut and hardened gear set.
Higher Mill speeds and more power transmission requires a superior
gear set. While a standard IH Mill max speed is 1600 RPM there is
a VFD motor option with a max spindle speed of 3600 RPM. Both motor
versions require only 220 volt single phase power.
Ways & Lead Screws
Precision Ground Ways and Quality Inch Lead Screws make movement
with an IH Mill a pleasure! Head movement with the crank is smooth
and easy compared to most mills.
IH Mill Specifications:
|Table Work Surface Area
||39.5" x 9.475"
|Longitudinal Table Travel
||30.125" Stop to Stop
|Cross Table Travel
||12" Stop to Stop
|T-Slots & Size
||Three Slots, 5/8"
||90° Left, 90° Right
||R8 (NT30 optional)
|Spindle to Table (Min, Quill Retracted)
|Spindle to Table (Max, Quill Retracted)
||2 HP 220V 1 Ph
|Spindle Speeds (RPM)
||100,190,330,480,910,1600 (VFD option 10 to 3600 spindle speed)
|Lead Screw Measurement/Dials
|Required Floor Space (for max travels)
||90"(H w/Stand)) x 87" (W) x 38" (D)
* These machines feature our hardened gears, which allow a 1750 RPM
motor to be replaced with an optional 2 HP VFD-driven 3400 RPM motor.
The VFD option allows operational spindle speeds up to 3600 rpm.
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