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Rotary Knife Jig

  
Overview
Rotary Cutter Jig, shown with a rotary cutter blade

I made the original version of this set as add-on parts for the Tormek SVD-185 / SVD-186 Jig so I could sharpen rotary knives for my wife.

The pieces added are

  1. the hand wheel,
  2. the bolt to hold it in place, and
  3. the fender washers.

Since then, I've created one using mostly 3D-printed parts as shown in the pictures to the right.

Usage Notes

I find that the most effective sharpening process is:

  1. Sharpen the blade using the DE-250 grinding wheel (1,200 grit). These blades are typically quite hard steel, so the diamond wheel is useful for setting the edge.

    Based on how the blade is held, when using the USB in the horizontal position, this is edge-leading grinding.

  2. If honing is desired, paper wheels on a bench grinder work well. Hone the blade’s edge using
    1. 5µm diamond paste on one paper wheel, followed by
    2. 0.5µm diamond paste on the other paper wheel.

    You can hold the blade using a 10mm bolt with a nut, and rotating it with a battery-operated drill. This is shown in the video noted below.

When cleaning the honing compound off the blade, DO NOT do that whilst rotating the blade in the drill. You may get lucky a few times, but at some point, the spining blade will somehow cut you badly. It is not worth the risk.

Sources for Buying One

You can purchase one from Colvin Tools.

Notes on Making One

You can 3D print your own parts. The components are:

  1. Rotary-Cutter-Sharpener-Sleeve.3mf (the blue part in the pictures above)
  2. Rotary-Cutter-Sharpener-Shaft.3mf (the yellow part in the pictures above)
  3. Rotary-Cutter-Sharpener-Handle.3mf (the green part in the pictures above)
  4. Rotary-Cutter-Sharpener-Handle-Knob.3mf (the brown part in the pictures above)
  5. Rotary-Cutter-Sharpener-Adapter-10mm.3mf (the red part in the pictures above)

You will also need these parts:

Item Source Part Number Comments
Flanged Button Head Screw, M6-1.0 mm Thread, 10 mm Long, 18-8 Stainless Steel McMaster-Carr 97654A379 Used to attach the Sharpener Adapter (red part) & blade to the Shaft (yellow part).
Socket Head Screw, M6-1.0 mm Thread, 16 mm Long, Black Oxide McMaster-Carr 91290A321 Used to attach the Handle (green part) to the Shaft (yellow part).
Thin Hex Nut, M6-1.0 mm Thread Size, 3.2 mm High, Brass McMaster-Carr 93187A250 Used to attach the Handle Knob (brown part) to the Handle (green part). This nut is tightened on the screw against the Handle, and is adjusted to allow the Handle Knob to spin freely.
Socket Head Screw, M6-1.0 mm Thread, 55 mm Long, Partially Threaded, Black Oxide McMaster-Carr 91290A342 Used to attach the Handle Knob (brown part) to the Handle (green part).

Tools Needed

These tools are needed:

These tools are recommended:

More Information

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