The shaper is a specialty woodworking machine used for profiling the edges of pieces of wood. Generally speaking, they’re commercial tools, although it's not uncommon to find them in professional woodworking shops. Even a few home woodworkers have budget shapers in their workshops.
When I mention profiling edges, I am referring to things along the line of cutting rabbets and beading, as well as tongue and groove joining of boards. However, probably the most important use of the shaper is for making raised panel doors. The shaper thins and tapers the door panels, as well as profiling the door's rails and stiles for the panels to set into.
Shapers use a vertically-mounted motor driven spindle to hold the cutting tools. The spindles are designed so multiple cutting tools can be mounted on the same shaper together. The spindle is then raised and lowered through the table, allowing for the different cutting tools to get to the workpiece. Workpieces are slid across the table to be cut.
All shapers are essentially the same, varying primarily in size. When we refer to a shaper's size, there are several things to be considered including motor size, spindle size, and table size.
On our review lists, we separate shapers into two categories, best shapers and best budget shapers. While there are many details of difference between the best of the best and the budget shapers, the major difference is size. Larger shapers simply cost more.
Important Shaper Specifications
Since all shapers are essentially the same tools, you're not going to find a lot of differences in features to look at. The main thing you need to understand is the differences in the shaper's sizes, so that you know what you are looking at.
Motor Size
Shaper motors vary from 3/4 HP to 7-1/2 HP. The larger the motor, the more it can cut on a pass. Smaller shapers are likely to bog down when making deep cuts or when cutting dense hardwoods so by purchasing a larger shaper, you eliminate that possibility.
Spindle Size
Shaper spindles vary from 1/2 inch up to 1-1/4 inches in diameter, with the larger shaper spindles on the larger machines. The spindle diameter and cutting tool spindle hole diameter must match for the tool to work safely. The spindle length can vary as well, ranging from 3 inches up to 6-1/4 inches. The longer the spindle, the more and/or larger cutting heads you can put on it.
Shapers allow vertical travel of the spindle (generally called spindle travel) adjusting the profile of the cut to the board, as well as choosing which cutter is being used when multiple cutters are stacked together. A few of the lager shapers also allow the spindle to be tilted which changes the profile that the cutting tool makes.
Table
The table of the shaper must be extremely flat and smooth to allow the workpiece to slide over it for cutting. Most tables are cast iron with the top surface ground to make it smooth. The larger the table surface, the easier it is to keep large workpieces flat and exactly perpendicular to the cutting head.
A few of the larger shapers have sliding tables which eliminates any problem with the workpiece hanging up on the table and ensuring a smooth cut. This increases the accuracy of the cut as well as improving productivity.
Fence
The fence is one of the most important parts of a quality shaper. Unlike a router bit, cutters for shapers do not have any sort of pilot bearing. This means that if the fence is not used, there is no way of controlling how deep the cut extends from the edge of the board. The fence must be used to control the depth of cut, ensuring that the profile is maintained.
The best fences are cast iron and independently adjustable with digital readouts. Fences will also come with holders to hold down the workpiece and prevent it from lifting off the table surface.
Other Considerations
Insert Holes
The table will have a hole cut in it for the cutting head to come through. The size of this hole is important, as it will define the largest diameter cutting head you can use. Inserts are used in this hole, when using smaller diameter bits. For shapers that have large insert holes, a number of inserts will be provided.
Turning Speed
The turning speed of the shaper may be important, especially if you are cutting woods that splinter easily or very dense hardwoods. On the smaller shapers, spindle speeds are fixed, while the larger ones usually are adjustable speed.
Motors
The motors on the larger shapers are also 230 VAC, rather than 120 VAC (normal house current). If you do not have the higher voltage wired into your workshop, you don't want to buy one of these higher voltage units.