The jig is a set of plywood rails to support the router which is suspended over the circular tabletop. The entire jig is constructed of 3/4" plywood; each rail is constructed of two strips of plywood to form an "L" shape for stiffness under the weight of the router. The base of the jig has a large round opening which accepts a hub. The hub is glued to the underside of the top and works as a pivot for rotating the top. I've provided a drawing of the jig to help you visualize it further. Here are some other things to keep in mind as you construct the jig:

-- It is important to size the jig to fit your brand of router and the diameter of the top which you are making

-- Attach a square baseplate to your router

-- Clamp the jig to the top of your workbench

-- Always clamp the router firmly in place in the jig before pivoting the top

-- Take light cuts

Recommended Router Bits for this project

The Amana Tool raised panel shaper cutter no.SC652 has a 3/4" bore and is supplied with a bushing for use on 1/2" spindle machines. With any machine operation, especially the shaper, it's important that you feel safe before
operating the machine. In other words, if it does not feel safe to you, don't try it.

First and foremost, with any shaper operation it is important that the cutterhead is covered by a guard. If your shaper did not come equipped with a guard then you should purchase one or construct one.

Page 94 of my book on the shaper shows a photo of a "box" style fence and guard which completely encloses raised panel cutterheads and provides a 3/4" thick barrier between the cutterhead and your hands. Also, with a factory fence a large opening is required to accommodate the large diameter of the cutterhead. In contrast, the box fence uses a very small opening which provides better support to prevent the workpiece from dropping into the cutterhead and kicking back. The front of the box can be adjusted vertically to allow for panels of different thicknesses, the top of the box is clear acrylic, and the back has a dust port. The box fence is secured to the top of the shaper with a large C-clamp at each end of the base.

Finally, a 1/2" spindle shaper has a smaller motor and less horsepower than a machine with a 3/4" spindle. So when using a large panel raising cutterhead it becomes necessary to take additional passes and lighter cuts.

View Shaper Box Illustration

You can flatten small to medium size planks and tabletops with your router, a jig to guide the cut and Amana Tool Mortising router bit no.45564.

The two-piece jig is a large sub-base for your router which is supported by parallel guide rails that flank the workpiece. The rails are attached to a 3/4" thick plywood base. Because the router is traveling in a flat plane on the guide rails, it will gradually remove the high spots from the workpiece and create a flat surface. Outriggers prevent the router from moving beyond the two outermost edges of the workpiece.

Keep in mind that there are limits to the size of the top which you can work with this technique. If the sub-base on the router is too wide it will sag under the weight of the router.

For your personal safety and for the smoothest possible surface, it is important to take light cuts.

View Illustration

It sounds as though you are climb cutting. Climb cutting is when the workpiece is fed the same direction as the cutter rotation. Instead, the workpiece should always be fed against the spindle rotation. Climb cutting should never be attempted without a power feeder because it is very dangerous. When climb cutting, the machine pulls the workpiece into the bit or cutter and it may pull your hands along with it and cause a serious injury.

Unlike routers, most shapers have a spindle reversing switch. The reversing switch provides greater versatility to the machine. The standard spindle rotation is counter-clockwise, in which case the workpiece is fed from right to left, against the rotation of the spindle.

If necessary, the shaper cutter can be inverted, and the spindle rotation changed to a clockwise direction. When set up this way the workpiece should be fed from left to right, which will be against the spindle rotation.

Some shapers, like yours, have a collet which allows you to use a router bit in the machine. Unlike shaper cutters which are bored to fit a spindle, router bits cannot be inverted and so you must always use them with the shaper rotating counter-clockwise. And, of course, the workpiece must be fed from right to left.

Also, keep in mind that the top speed of most shapers is typically 10,000 RPM while routers usually run at twice that speed, typically 20,000 RPM or more. So when using a router bit in a shaper it is necessary to reduce the feed rate.

To increase safety as well as the smoothness of the cut I recommend that youuse featherboards to hold the workpiece firmly to the table and fence. And use a guard whenever possible to shield your hands.


View Illustration

Crosscutting wide panels for doors and tabletops is a challenge. The miter gauge on many tablesaws does not provide enough support to the stock for an accurate cut. I have a sliding mitersaw which does a great job but it is limited to a twelve inch wide panel. Aftermarket accessories which attach to the saw are wonderful tools but they are somewhat expensive and unless you operate a production shop they may be out of your price range.

I suggest that you make a second attempt at the crosscut sled. I've included a photo and drawing of the one I use in my shop. To fine tune the sled to cut precisely 90 degrees, I make fine adjustments to one end of the sled runner. Once the sled cuts square I fasten the runner securely with an additional screw. It can be a bit tedious but once set up a sled is a great way to cut a perfect 90 degree angle on wide panels. However, one drawback to the sled is that the runners wear. I solve that by using hard maple for the runners. Also, when using the sled I push it gently to the left (away from the blade) as I push it forward. This compensates for minor wear on the runners.

Also, I don't use use of the crosscut sled for stock thicker than 1-1/2". Otherwise you'll risk weakening the frame members at the front and back of the sled.


To construct the sled in the drawing here are the steps that I use:
1. Cut a 3/4" plywood panel to fit the top of your saw. My sled measures 3/4" x 26" x 40".

2. Mill two strips of maple to fit in the miter slots on your tablesaw. The strips should fit precisely because they serve as the runners for the sled.

3. Fasten one runner to the plywood panel at 90 degrees.

4. Now fasten the frame members at the front and back of the sled.

5. Attach the guards. The guard at the rear of the sled is just a block that is glued to the frame. The block keeps the blade buried at the end of the cut.

6. Test the accuracy of the sled. If necessary make minor adjustments to the runner. Once it is cutting square attach the second runner to add more stability.

For smooth, splinter-free crosscuts I use the Amana Tool Prestige saw blade. And because it is a combination blade I can keep it mounted on the tablesaw when ripping.
 
View Illustration

It sounds as though you're having trouble with snipe. Snipe occurs when the outfeed fence is not adequately supporting the stock. The length of the snipe is equal to the fence opening, in this case 1-1/2".

With some types of bits, such as the Amana Tool glue joint bit #55388, if the cutting height is equal to the stock thickness the entire edge of the stock will be removed when routing. In other words, none of the original edge remains on the stock after it passes the bit. Once the stock is no longer supported by the infeed fence it drops into the spinning bit creating a heavy cut, or snipe, at the trailing end.

The key to preventing snipe is in the fence adjustment. One method is to adjust the outfeed fence forward slightly to compensate for the loss of stock. Shapers are designed with a split fence for this adjustment. An micro-adjustment knob allows you to independently adjust the outfeed fence forward. However, most commercial router table fences lack this feature. Instead, the outfeed fence must be shimmed. Although this method works, it is somewhat fussy because the cutting depth must be adjusted to equal the shim thickness.

The method which I prefer is to adjust the fence tangent to the smallest cutting diameter of the bit. I position a straightedge against the bit and slide the fence forward until it touches the straightedge. This method provides you with the full shape of the profile without a loss of stock and snipe. 

View illustration

I'm glad to hear that you're benefitting from the Q&A column. Please tell your friends about the column and visit often.

To bevel the edges of the 3/8" thick box panels I would use Amana Tool no.49414 chamfer router bit. This bit cuts an angle which is 30 degrees from horizontal which will create a 60 degree angle along the edges of the panel.

To miter the ends of the frame members at 60 degrees just rotate the miter gauge on your tablesaw to 30 degrees.

View Illustration

The Profile Pro system is one of my favorite style of shaper cutterheads because the head uses interchangeable knives. This provides a tremendous amount of versatility while making it less expensive than purchasing individual brazed cutterheads. There are a number of different profiles to choose from and you can also order blank knives to create a custom profile. For a custom profile take the head, blank knives and a full-scale drawing to a professional sharpening shop.

Snipe is caused when the trailing edge of the workpiece drops into the fence opening slightly. One common cause is that the workpiece is slightly bowed along the length. I avoid this scenario by first jointing the face of the
stock straight and true before planing it to thickness.

Another common cause of snipe with shapers is that the split fence halves are not parallel or in the same plane. For example, if the outfeed side of the fence is just slightly lower than the infeed side the trailing end of
the workpiece will drop into the fence opening slightly. The solution is to fine-tune the fence halves so that they are perfectly parallel and in the same geometric plane.

After carefully aligning the fence halves I suggest that you attach a one-piece wooden auxiliary fence to help further eliminate the problem. Unlike two separate fence halves, a one-piece fence is far less likely to come out of alignment and it also allows you to reduce the size of the fence opening. Reducing the fence opening not only greatly reduces the likelihood of snipe it also increases safety.

Also, consider milling the stock slightly wider and ripping it to final size after shaping. An extra 1/4" in the width above and below the profile provides a "lip" to ride the fence above the cutterhead opening which virtually eliminates the possibility of snipe.

Finally, use featherboards to hold the stock firmly to the fence. Featherboards positioned on both the infeed and outfeed side of the fence will not only aid in eliminating snipe, they will also provide an additional margin of safety.

Regarding cutterhead diameters, as a general rule large diameter heads are designed for larger shapers with spindle sizes in the range of 1" to 1-1/4". The large head diameter is required to provide space for the larger spindle
bore as well as the locking gibs and screws which hold the knives securely in place within the head. 

View Illustration         

Shaping an eight-sided taper is really quite easy; it's really just a four-sided taper with chamfered corners. I use a table-mounted router and a 45 degree chamfer bit such as Amana Tool no.49402.

When shaping a chamfer on a taper the cutting depth must gradually and continually increase as you shape from the small end to the large end. The solution is a jig with a tapered base which supports each end of the leg at the correct height.

As you can see from the attached drawing the jig is tapered in both the horizontal and vertical planes. 

View Illustration

Splintering or tearout can occur when routing across the grain; when you route the long-grain edges of the panel the tearout should shape away. However, when you describe the workpiece as shattering it sounds as though it is being grabbed by the bit because it is not sufficiently supported.

When shaping raised panels on a table-mounted router I use the Amana bit no.54117 with excellent results. To provide optimum support for the workpiece as it is being shaped I close the fence halves to create a zero-clearance opening. Then I attach a Paneloc guard/ hold-down. The Paneloc will shield the bit to protect your hands. It also applies vertical pressure to hold the workpiece firmly to the table for a smoother cut. Panel-raising bits are among the largest bits for use in a router. For this reason use a slow feed rate and listen to the sounds of the machine. If it seems to be bogging down take lighter cuts.

Finally, before you shape a panel inspect it closely for small cracks on the ends that are left over from the drying process. Warped, cracked or otherwise defective stock can shatter as it come in contact with a high speed router bit.


Recommended Tools
Amana bit no.54117