The differences between a router bit and a shaper cutter is rather large, and while they both serve the same basic function, the methods of use are quite large.
For one, router bits are made from a single piece of high speed from the shaft to the cutter, and are designed to run at speeds up to 25,000 R.P.M's. The shafts range in size from " to " in diameter, and are held to the router with a collet. This is just a split circular tapered ring which squeezes against the bit, as the collet nut is tightened. Some of these steel blanks form the cutter as well, while others have the same shaft and cutter head, but with the addition of a carbide tips brazed to them.
The high speed steel bits are cheaper, but don't last as long as the carbide tipped bits. They are also prone to burning the wood, particularly if they have what's called pilot bit incorporated with them. This is just a stub of steel protruding from the bottom of the bit, which is designed to ride against the wood being shaped. This stub is rather useless as the amount of work required to remove the burns just isn't worth the effort.
The carbide tipped bit will have a roller bearing on the bottom to follow the wood edge being shaped. These bearings run smoothly, and as long as too much lateral pressure isn't applied to the contact point of the wood, they will leave no trace of having been used. If lateral pressure is over applied, they will leave a small groove, or track where they made contact with the wood. A nice steady light pressure is all that's needed.
Bits without this stub or roller guide must be used in conjunction with either an edge guide mounted to the router, or with a router table and fence. These bits are available in many sizes and shapes, and will handle most woodworking applications, especially for the home wood shop.
Shaper cutters on the other hand are generally much larger, and are designed to run at slower speeds. Either 7,000 or 10,000 R.P.M's, is the norm. The speed is changed by a stepped pulley system, much like a drill press. The increased size is partially due to the fact they have no shaft. They have a hole in the center of varying sizes, which is slid over the appropriate sized spindle of the machine. When buying cutters it's important to keep the diameter in mind or you may end up with a cutter not compatible with your spindles.
This spindle is removable and most shapers come equipped with at least a couple different diameter spindles. These can also be ordered separately. Many shapers come with a collet in " and " configurations to allow the use of router bits as well.
One advantage of shaper cutters is the ability to add cutters in different configurations or guide bushings and bearings which serve to guide and / or alter the resulting cuts. Burning is pretty much a non issue as the cutters are spinning at a much slower speed. Uniform moldings are much easier to accomplish with the use of a power feeder, which applies steady even pressure which is key to excellent results.
Copyright 2007 - Lee A. Jesberger.
access point vs router
Niciun comentariu:
Trimiteți un comentariu