I enjoyed a couple of books that you wrote, "Shaping Wood" and "The Shaper Book." I read the "Shaper Book" prior to purchasing a shaper since I am mostly self taught.
I am an amateur woodworker. I am going to build my own kitchen cabinets. And I make a lot of molding for picture frames and for my home. I recently purchased the 88mm Profile Pro aluminum cutterhead for my new 3hp shaper. It molds beautifully and the finish is much better than expected. I have a couple of technical questions where a more experienced person may know a simple solution:
1) I am having a problem with snipe on the last 2 or 2 ½ inches. All of the wood is being hand fed, and while I’m comfortable doing this, the snipe is irritating. I suspect that the large cutterhead (larger than the router bits I’ve become accustomed to) is creating a large gap in the split fence. Would a rub collar help, and what sizes since there are so many blade shapes? Also, would a power feeder be any help since they are reliant on a fence for support?
2) The table opening of my shaper is barely too tight to lower the cutterhead(with knives) below table level. This is definitely limiting, and I plan to purchase the 68mm head just for that reason. Why are there so many sizes of the cutterheads & does the diameter affect the quality of the cut?
-T. Allen Wyatt
Winter Haven, FL
Our Expert
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.
