Originally Posted by
Dev Emch
Hi Tom...
I too have never really owned a true router table. But that is because I hate routers. Yes, I own three of them. They do have their uses but over the last few years, you have seen a plethea (sp?) of new products invade the woodworking shows. Every argument starts out with the same jingle... " Have you ever had these horse apples happen to you?..... well, today is your lucky day mr. whipper snapper... for $199 dollars and 99 cents I will sell you the new and improved, patented helical whachamagigger. Now you can do horse apples like the pros with less effort and no skill."
Well as you guys suspect, most of this gizz are new attachments or improvements to the router table. Now I like my Leigh D-4 jig and I will use my Porter Cable 690 vibrator to knock of 10 minute quickies with the rest of you but that is where I must draw the line.
The industrial wood shaper has been/and is the most important woodworking machine i own. I have used it to do the impossible including using it as a jointer and a moulder. But all of these attachments and gizzmos are designed to make a router perform like a shaper. Each year, more and more products reach the market trying to capitalize on this phenom.
Router bits have gotten larger and larger. Today's panel raising router bits are 3 inches in diameter! They must be run at 10,000 RPM for safety reasons. One reason is that the shaft is 1/2 inch in diameter. Look at the shear area on that shaft! The corresponding 3/4 in, 1 in or 1.25 inch spindle is double to several times the area. Not only is the shear area very small but steel does not leave the rolling mill in an homogenous state. When this bit is made, a section of 3 inch round stock is chucked up and worked on by a metal lathe to produce the bit. The strongest grain in the steel is in the outer section of the billet and the weakest section is right in the middle. Right in the area that will hold your bit together! In a corresponding shaper cutter, the weakest area is bored out as debris! So right there, you have an argument for using real shapers.
Then you have the cut depth, feed rate and spindle speed. The tip speed, hook angle and clearance angle on a router bit are designed to work more like finicky dental drills instead of industrial cutting bits. You have to take several light cuts to accomplish the same task. Even though a shaper cutter is much more aggressive in its hook angle and clearance angle, it is designed to produce a glass smooth surface. But at the same time, you can feed a rough cant into a shaper and just pulverize anything that is not the shape your trying to finish with. And when your using say 1.25 inch spindles with 5 to 10 HP motors with 6 inch diameter steel heads, I do mean PULVERIZE!
Router tables use routers. These are powered by universal motors which derive the horse power output via RPM. So for a router table, a typical router would be a porter cable 7518 which has variable speeds from about 10,000 to 20,000 RPM give or take. Anyone who has used a router knows that characteristic sound of when the router plunges in and begins to take a big bite. That is a loss of RPM. So now you have to deal with fluctuations in RPM depending on load. An industrial shaper is powered by an induction motor which is not nearly as susceptable to this. In fact, at 5 HP and above, the typical shaper job will have an almost impercievable reduction in RPM. You also get a type of harmonic balancing affect from the mass of the cutter your spinning. This helps reduce some of the harmonic blemishes you sometimes find on the finished job.
Puting a sliding table on a router table is an interesting feature. Now why would you wish to have a sliding table on a router table? Simple. End grain cuts. I came up with what I call "THE SHAPING TRIAD". There are three types of wood shaping operations dominated by three types of wood shapers. The first type of cut is called a molding cut and represents a cut along or with the grain. This is the type of cut that a moulder like a wynig would do. It is the easist type of cut and most often, the tooling lacks any shear angle whatsoever. You will find optimum hook and relief angles for this type of cut. Most of the cuts done on a router table or shaper using a fence will be this type of cut. The second type of cut is called a coping cut or end grain cut. This type of cut is done by a machine called a tenoner and the tooling frequently uses high shear angles and the hook and relief angle are designed for this type of cut. The third type of cut can be either molding or coping or a combination. This is the shaper or router tables area of expertise. A shaper can be configured to operate as either a moulder or a tenoner based entirely on setup. End cuts have traditionally been done on router tables and shapers by using the mitre gage in a mitre slot or some variant thereof. The addition of a sliding table is an attempt to mimick the behavior of a dedicated tenoner.
But there is one more thing to think about. In a standard cope and stick application where you have two rails and two stiles, there is an issue with the joint. In order for the rail to fit the stile, you have to cut a reverse of the profile using the coping cutter of your set. This leaves a feeble stub tenon to fill the gab on the moulding cut which holds the groove. Often this is the result of using limited shaper and router tooling to achive this cut. When this is done using a tenoner type approach, one first cuts a basic tenon long enough to sink into the stile's mortise. Then, the tenoner's coping cutter "under cuts" the actual reverse profile of the stile while this cutter is flying over the surface of the previously cut tenon. One coping cutter can cut any size of tenon. Often, with router type tooling, your limited to just the stub tenon which is not strong enough for many applications. The strength of the glue joint depends upon the surface area of the long grain of the tenon. The actual under cut face is end grain so its of little use.
In terms of the afore mentioned argument, your stuck with the stub tenon when using a router table. On the other hand, I can use a large coping disk with a reverse profile on an industrial shaper to under cut any face as needed resulting in any size tenon that I may need. I can also use, for example, a freeborn profile set to cut the stub tenon as before. The point being that I have choice in my approach.
The one area where router tables actually have one up on the shaper is when using very tiny bits and esp. bits that have a vertical orientation. (i.e. using a spriral cut router bit) Here I can do plunge cutting and cut items like blind dados which are much harder to do on a shaper. Of course I can use a router bit spindle adaptor on a shaper but that assumes the shaper can reach speeds of 15,000 to 20,000 RPM. You can run these bits much lower but the quality of the cut and the pleasantness of the cut can be diminished resulting in blow out or burns, etc.
Lastly, most router tables run bits at about 15,000 RPM on average. The router bit has two knives and very little bite. Nonetheless, the typical woodworker is not able to feed the item through fast enough to maintain the chip load and cut for this configuration. The result is that the router bits become prematurely dull. This may be a bit difficult to understand at first because of the perception of RPM drop and the tiny amount of stock being removed during a pass. But its true. Even though your taking only a fraction of what a shaper cutter can pulverize, you still need to maintain a brisk feedrate or you run the risk of dulling knives and leaving burn marks on woods such as cheery and maple.
You will find quite a few shapers out there. An ideal shaper for a hobbyist or beginner would be something along the lines of the Delta/Rockwell HD or Powermatic 26 or 27. Many of your trick fences such as those now for sale by Jessem via woodcraft or rockler can be adapted to fit these shapers as well. The Incra fence system can also be used. In fact, these two shapers do have router bit adapters available and are used often. The HD will have two speeds. For the most part, you need to run at 7000 to 8000 RPM. If your off by a bit either low or high, it does not really matter. Most of your freeborn PC type heads are designed to run at 8000 RPM. The same is true for most 1/2 in to 3/4 inch bore heads which run at 8000 to 10000 RPM. I would not use a 6000 RPM or lower head on an HD. These are often honkin sized steel moulder type heads which will cause you to wet your pants if you try to spin these on an HD. Just stick with the smaller heads like those green woodcraft heads or freeborn heads.
As for buying machines. I have seen many MANY delta/rockwell HD shapers go at auctions and some used dealerships in the $650 dollar range. These are often 5 HP machines and will work quite nicely in the typical home shop. Another source for finding these used is ebay. If you price new, then look at comparing apples to apples and not apples to oranges. If you buy a new or used Delta HD, then your going to have to look at a router table which has the following: PC 7518 router, heavy duty bull dog or jessem type router lift, jessem type router fence, complete router table cabinet. At last count, woodcraft was getting over $1000 dollars for a complete jessem router table minus the router. This blew me away! For this money, I can get easily get a real industrial shaper esp. if I go used. The down side to this is that many shapers will have 3 phase motors and that will require you to go to three phase. I would say that over 60 percent of those I know who have old iron shapers have built their own phase converter including myself. Its not a big deal. Just another shop project. Folks, the loss of manufacturing in this country has dumped a ton of good stuff onto the market. Now is the time to take advantage of this surplus by putting heavy iron into your workshop!
Also, for those who have gone to the woodworking shows, you will know that outfits like "The Woodworker's Choice" have significantly increased the number of shaper cutters available through lines like Old Hickery. Price wise, they are not much different than the router bit cousins. Just a hole instead of a stick and, of course, different hook and relief angles.
Pass the router table and go to the shaper. Long ago, a car salesman kept saying to me, "well, its just like a honda this and well its just like a honda that". I kept thinking "Why is this guy always comparing his wares to a honda? Does he not have a feature set that can stand on its own? If its just like a honda, why not just buy the honda in the first place? That would be truly like a honda would it not?" Same thing applies to the shaper. All router tables no matter how well they are made or how much bling bling the dealerships can apply to them are, well, nothing more than router tables who are shaper wanna-bes. And after you use your first true wood pulverizing shaper cutter, you will never look at your router table again... In fact, you will grab your digtial camera for the ebay photos of your router table!
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