router vs. shaper

[Louie Ballis]

I am tinking of upgrading from a router table to a shaper for a variety of reasons.

My question is not which is better or more versitle but rather why are they powered so differently?

A typical router (hand held or talbe mounted) is usually 1 1/4 to 2 1/2 while a shaper table will be 3/4 (grizzly) to 1 1/2 +. Why does the shaper need less power to turn a larger (heavier) cutting tool?

Am I missing something here?

thanks

Louie

[Dave MacArthur]

Completely bogus HP ratings for routers. Measured differently, maybe peak full-load HP just as the motor stalls or at startup. Universal motor in router.

1 HP basically draws 10 amps... most you can power on a 15A circuit is 1.5 HP usually, so obviously a 3.5 HP router ISN'T really.

Try doing a search using the button up above on "router horsepower" and you'll get about 30 threads on this with almost every conceivable in/out of the question covered You're not the first person to look at it and say, "HEY! Something's bogus here!"

Shaper is more powerful.
http://www.sawmillcreek.org/showthread.php?p=1391993

[Van Huskey]

Dave has it.

The difference is the wildly inflated HP claims of universal motors, like the ones in routers (think 6hp shop vacs) compared to the more accurate ratings of induction motors.

[Peter Quinn]

At 3/4HP to 1 1/2HP sounds like you are talking about a pretty small shaper, and in that case the power difference is mostly semantics. IME shapers that small actually DO perform pretty close to a 3 1/4 HP router in a good table. The numbers are a ratings game and mean very little. Small shapers typically turn a 1/2" spindle, may spin fairly small 3/4" bore cutters, but mostly are relegated to the smaller 1/2" bore cutters. So you have a 1/2" shank or a 1/2" bore, take you pick. Some may have a 3/4" spindle, but that few horses wont turn the bigger 3/4" cutters very well. And if you compare the motors in AMPS, router versus small shaper, its pretty close. The very small shapers do have much in common with their bigger cousins, like iron tops, split fences (possibly depending on make), good height mechanisms, more mass than most router tables, and induction motor (quieter), etc, so there are advantages.

Now if you asked what the difference between a 3HP shaper and a 3HP router is, well, thats a whole nother thing. A 3HP shaper is a lot more machine than a 3HP router, spins bigger cutters by far, can handle a feeder easily, can make many moldings and raised panels in a single pass, etc.

[Van Huskey]

Peter makes some very good points, my rule of thumb is a 1 1/2hp shaper has just enough more power to notice over a PC 7518.

To me a 3hp shaper is the place to be for a variety of reasons. Considering right now you can get a Grizzly 3hp shaper shipped for under 1K, it makes a full bore router table look a little silly in some ways. A top shelf lift and a 7518 are already over $600 then you have the rest of the setup. But in the end they are apples and oranges to some degree, thats another place I would just rather have both.

[Dana Vogel]

Routers achieve their HP rating by extremely super hi RPM's(peak HP) but at the cost of torque, on the other hand conventional electric motors achieve their HP rating with much lower RPM's and much higher torque kind of like comparing hi revving lower torque gasoline engine to a low revving hi torque diesel engine. I like my 5 HP SECO shaper.