Single-Blade Moulder

Advice on running a moulder with just one knife, for the sake of economy on short custom runs. February 12, 2009

Does anyone know of a moulder that utilizes a single blade. I need to match historical mouldings from a few inches to several feet from time to time. Grinding one blade profile is much more desirable than a set of three for such a short run.

Forum Responses
(Cabinetmaking Forum)
From contributor A:
Woodmaster has 1, 2 and 3 knife heads. Originally it was designed to run flat back knives in the planer head. They also have 1 and 3 knife flat back heads.

From contributor R:
I own a Woodmaster 718. I virtually always use a single knife. The Woodmaster is an amazing machine. The quality of the moldings is insane once you learn the proper techniques.

For making your own knives, I recommend Viel's knife grinder. I had one that I used with my Woodmaster. It works fine for single knife heads, but worked just as well for two knife shaper heads that I used to make knives for. I made a ton of money off these two machines when I was doing short run custom moldings.

From contributor K:
I'm intrigued by the concept of a single knife moulder. How do you go about balancing the centrifugal forces at play for every new profile?

From contributor B:
To contributor K: it’s really not too difficult. The small molding head has a slot cut out of it for the knife and gib. The trick is to make a matched gib for each knife. I used brass bar stock, cut the proper angle on it at the table saw, then cut lengths off as needed. If I recall correctly, the total weight of the knife, gib and set screws needed to be 19 oz. I bought a fairly inexpensive digital postal scale at Wal-Mart that could measure tenths of an ounce. I found that you could be off by a fair amount and not have noticeable vibration (the accessory bar is 1 1/2" thick) but obviously, the better the balance, the smoother the finish.