RC-33 planer knife gauge

[Bob Cumming]

Newbie here. Wanted to advise that I successfully built and used a small planer knife gauge that I'm told is a rare item among woodworkers who own the old RC-33 type 13" planers. I bought mine earlier this year from a neighbor's estate that hadn't been used for many years. Although the original manual was there, the knife setting gauge was long gone. After several unsuccessful attempts to locate one, I posted a question on this forum and soon received a response the gist of which was that the gauges are almost impossible to find. So....I built my own which, I think, is an improvement over the original and significantly less costly than new types on the market today.

Mine has only one moving part, i.e., the threaded thumb screw that is easily adjusted up/down to set the distance the knife's edge protrudes above the rotor's face. Two small rare earth magnets hold the gauge snug to the rotor to permit sliding a mechanic's feeler gauge between the thumb screw's point and the knife edge. The rotor does not have to be positioned with knives on top, which may be adjusted from an angle. The magnets are key to maintaining the gauge perfectly still while adjusting the knives. The tiny magnets fit into milled recesses in which they were attached with J B Weld. After curing, the epoxy and a corner of each magnet were machined down to ensure precise attachment to the rotor's surface. Relocating the gauge involves simply sliding the gauge frame over the slot in which the knives are set. There are no protrusions that interfere with siting the thumb screw point over the knife edge or tightening the bolts that secure the knives in place.

After setting the knives to .040" my first pass with a 2X6 was planed with precision, very little noise, and virtually no vibration. I planed many recycled redwood deck planks from 1.625" thickness to 4/4 and measured the thickness along both edges with a Starrett digital calipers. Variation was about .002" ( + - ) across the planed surfaces. My next project is to use the gauge to plane wood to precision dimensions for building a Rolex.

I am in contact with a patent attorney with a view towards having them made commercially. Because many planers of which I'm aware utilize similar cutter technology, the one-size-fits-all concept appears suitable to a variety of planers. If not, smaller/larger sizes of gauges can easily be replicated. Point being, the KISS theory seems perfectly suited for this application rather than more complicated varieties that began life based on the SWAG theory.

I've got several good photos that I'm anxious to share but would prefer to wait awhile until the patent dude in Houston gets back to me on whether or not he can make this bird fly without me taking a 2nd mortgage. Meantime, I'd be interested how many of the membership has an interest in this gizmo.

Fire when ready. Thanks.

[Bruce Volden]

Bob,

I will be watching this thread closely. I picked up an old planer from a school for $65 a year or so ago. It came with the stand and 2 sets of NEW blades. Of course the kids at school had abused it over the years but still ran very strong! I disassembled and cleaned, replaced things as needed.
I had resorted to a planer pal jig for setting the knives, it worked but it was a finicky thing to place on the head.

Bruce

[Ken Combs]

I have one of those planers and would have interest in tool to set the knives. I use the depth rod on a digital caliper. Kind of difficult, but it works.

I would really like a version that incorporates a thin insulator between the tool and cutterhead so one could use a battery and light to show when the knife contacts the depth gauge.

[Bradley Gray]

I have a big, old 24" planer that used to take about 2 hours to change knives, then I bought a pair of magnetic knife holders and now it takes 15 minutes tops to change knives.