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The popularity of big hand-held routers and their relatively low
cost along with economical cutters for them make it natural for them to be used inverted
in a table. This configuration gives the router the ability to perform much the same way
as a shaper and gives rise to the question what is the difference between a router
table and a shaper?.
The typical woodworker - hobbyist could get by very well using a
router table to perform the function of a shaper. Although a shaper and router table can
perform the same function and may appear similar they are however quite different machines
in several important areas.
The following are a list of differences between a common router table setup and a shaper:
||Even though a router is
advertised as having a 3hp motor, they are NOT truly as powerful as a 3hp shaper with an
induction motor. The shaper motors are likely to be rated for constant use and are capable
of taking much bigger cuts than would ever be attempted with a router. Compared to a 3hp
router, a 3hp shaper motor has significantly more torque. A 3hp induction motor is more
dangerous as well since it can use this torque against the user in a kick-back situation.
||The universal motors used
in routers operate with a higher noise level than a shaper that uses an induction motor.
||Most shapers have a
maximum speed at the lowest end of the router rpm range, most router bits are designed to
operate best at speeds over 10k rpm. The same bit in a router spinning at over 18k rpm
will produce a noticeably better cut using small diameter bits. This issue would mainly
impact box and dovetail types of cuts.
||Larger shapers have better
magnetic switches. When power is removed (like a tripped breaker), the machine will not
start up when power is restored; the start switch must be re-pressed.
||Router inserts will often
have the ability to accept PC type guide bushings for use in template work.
||It is often far easier and
faster to change a cutter in a shaper than it is in a router.
||There are more profiles
available for shapers than there are for routers. In addition, there are several sets of
cutters than can be stacked. It may not appear that there are more shaper profiles
if all one looks at are the standard woodworking catalogs but a glance through dedicated
tooling catalogs would confirm this.
||Shaper cutters last longer
than router bits. This usually isnt an issue since most router bits would never
become worn-out from use by a hobbyist.
||Cutter height adjustments
are easier and faster on a shaper. However, many routers are equipped with high resolution
adjustment mechanisms thus they can be adjusted more precisely.
||It should be easier to
mount a power feeder to a shaper than a router table setup. A power feeder will allow the
shaper to climb cut very safely. Climb cutting will often produce a superior
||Shapers have cast iron
tables that are far better work surfaces than typical laminate topped router tables.
||Shaper cutters and guide
bearings are more expensive than equivalent router bits.
||Shapers usually come with
adequate fences with dust collection ports and hold down devices; most of these items are
added cost extras for router tables.
||Most shapers have the
ability to reverse the rotation of the spindle. This allows the operator to decide which
face of the piece is the reference or to use cutters with more than one profile.
||Shaper cutters have much
larger diameters than router bits. This produces a better cutting action with less ripple
than a similar router bit due to tip speed and the angle of attack between the work-piece
and the cutter.
||If the cost of a small
shaper is compared to a dedicated router table setup with the accessories needed to gain
some of the shaper-like benefits, a router table is probably more expensive (see cost
Since I think a 3hp router is generally as powerful
as a 1hp shaper, I have put together the following cost example based upon this. The
particular brands listed have been chosen because they are readily available and appear to
be quality components.
|Comparable Shaper Costs:
||Delta 1.5hp shaper
||Jet 1hp shaper
||Grizzly 1.5hp shaper
|Router Table Component Costs:
||Dewalt 625 plunge router
||Veritas router table top
||Veritas router table fence
||Veritas work hold-down
||Veritas work hold-down
||TWC brand steel bench leg set
||Total router table cost
One very big difference between a router and shaper is in the available selection of
cutters or tooling. Router bits are much smaller in diameter, cheaper, and
come in fewer variations than their shaper equivalents.
As an illustration of variety, consider a straight router bit. It
is common to find this type of cutter available in:
- Simple straight of various diameters and cutter heights.
- Solid carbide spiral capable of plunge work.
- With guide bearing on top.
- With guide bearing on bottom.
An equivalent shaper cutter could be found in:
- Solid body with brazed carbide cutters (like a router bit). Can be
used in combination with different sizes of separate bearings that can be placed either on
top or bottom of the cutter as desired.
- Insert type cutter head with wing cutters on the top /
bottom to scribe a clean shoulder with no chip-out. Can also be used with separate
- Sheer angle insert type cutter head with wing cutters
on the top / bottom to scribe a clean shoulder with no chip-out. Can also be used with
- Jointing cutter head with four-sided inserts arranged in spiral or
straight location patterns. Can also be used with separate bearings.
- Multi-profile heads that can accept different replaceable cutters
including straight. Can also be used with separate bearings.
In addition to the example listed above, there are several
profiles and special cutters that are not available for use on a router. A few examples of
- Large diameter, variable width, stacking tenon cutters.
- Special relieved edge rail and stile cutters.
- Matched sets of stacking rail and stile cutters that can be used
for both passage doors or common kitchen cabinet doors.
- Insert cutter heads to accept custom ground profiles.
There can also be a big difference in the cost for tooling to use
in a router or on a shaper, below is a sample list of profiles:
|straight, 1/2" dia
||straight, 1 1/2" high
|straight, 1/2" dia
with top bearing
||bearing, 2 5/8" dia
|straight, 1/2" dia
with bottom bearing
1/4", 3/8" rad
|roundover, 1/4" rad
|roundover, 3/8" rad
|chamfer, 45 degrees with
||chamfer, 45 degrees
|bead, 1/4" dia with
||bead, 1/4" dia
|raised panel, horizontal
||raised panel, horizontal
|rail and stile, 2pc set
||rail and stile, 6pc set
The costs used in the example above are at the low end of the
cost range for either sets of tooling and is presented just to illustrate typical
Router Bits in a Shaper
Most shapers will accept router bits with the use of an adapter, these adapters may be an
optional accessory depending upon the particular shaper. The router bit adapters used in
shapers are not usually the self ejecting type that are commonly found on
routers, this can make bit changes in a shaper less convenient than a router.
The usual top speed of a shaper is about 9,000rpm, the usual top
speed of a router is about 22,000rpm. Consider a ½ straight bit installed in both
machines to be used to cut box joints. The tip speed of the bit in the router (at 22k rpm)
will be around 48 feet per second (fps), this will result in a very clean cut for the
joints. The tip speed of the bit in the shaper (at 9k rpm) will only be about 19 fps, that
is significantly slower than the router. The result will most likely be a lower quality
cut on the joints. There is more than a feed rate issue involved here, a small diameter
router bit is specifically designed to cut material at a high rotational speed, that is
where the best cutting action is obtained.
On the other hand, consider a 3 ½ diameter raised panel
cutter run in a router set at 9,000rpm (large diameter bits
MUST be run at the slowest speed on a router, they should NEVER be run at high speed!). The tip speed is about 137fps. The same bit can be run on a shaper at
9,000rpm, the bit wont know the difference and the cutting action will be the same
because the cutter will be turning at the speed it was originally designed to operate at.
Depending upon the motor size of the shaper the overall operation may be a little better
on the shaper though due to a potential significant difference in available torque.
To give an additional example, consider using the ½
diameter straight bit in a router to make a rabbet. With the router set at 22,000rpm the
tip speed is about 48fps. A 4 diameter shaper cutter running at 9,000rpm has a tip
speed of 157fps, at 6,000rpm it would be 105fps. Because of the tip speed, torque, and the
cutting action which takes place more tangential to the stock, a higher quality cut should
be the result.
The typical woodworker could get by without ever using a shaper, it would be very
inconvenient in the least to get by without using a router. The same router that can be
used for hand-held work can be used for many router table operations which
will make profiling operations more convenient.
In reality the question isnt which machine to use but which cutter to use. If high
performance, more versatile, or special cutters are desired (or for a lot of heavy
cutting) a shaper is the tool to use. For pierced work, and finger type
joints, a router table is preferred.
For reasons stated above, even if a woodworker had a shaper
available that would not make a router table setup redundant.