
Wishbon 2 - A Tool for Sharpening Small Drill Bits

It was always difficult for me to sharpen a drill with a diameter of less than 3 mm. Most of the available tools for sharpening drills are not designed for this, and manual sharpening was not always obtained. Sharpening drills with a diameter of less than 1 mm did not work at all. (And for large drills there is DBS -100)
Once I came across a description of a little-known tool Wishbone for sharpening small drills and I decided to do something similar, but suitable for manufacturing on an FDM
printer.
The result is Wishbone 2. This tool allows you to quickly and efficiently sharpen drills with a diameter of 4 mm to 0.5 mm without any special skill.
Made using 3D printing on an FDM printer, easy to assemble, inexpensive.
You can order a made Visbone 2 or STL file and instructions for self-production by calling:
+380983870850 via: Viber, Whatsapp
or you can find via the feedback form.
A manufactured Wishbone 2 costs $ 6,
Shipping cost by Ukraine post:
-
with tracking $ 10
The model for printing and drawing cost $ 2
You can pay for your order WebMoney or make a transfer to a Ukrainian bank card.
Or you can follow the links below and buy there:

The work of Wishbone 2 is shown in the video:

For sharpening drills a diameter of 1 ... 4 mm I used sandpaper grit 180 ... 320, for sharpening drill bits with a diameter smaller than 1 mm - grit 320 ... 1000. Please note, when sharpening very small drills, it is necessary to hold Wishbone 2 in the area of the axis of the lower roller, without pressing. To avoid skewing the pressure plate when installing small drills, you can use two fragments of a regular match.
The angle of sharpening ϕ1 at the apex can be changed simply by changing the offset of the drill. Preservation of symmetry is ensured by an equal number of passes on the abrasive, or corrected by additional passes. It is better to control the quality of sharpening small drills with optics.
The rear cutting angle α is set “by eye”, with sufficient accuracy, it is not difficult, it can be estimated as follows:
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take a matchbox, place it vertically, on a narrow long edge,
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put the school protractor to a short edge and notice how it looks at the same time,
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tilt the box to the right by 5 degrees, mark the difference with the previous position,
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now tilt the box to the right 40 degrees
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A tilt of 5 to 17 degrees provides a rear cutting angle α
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A slope of 25 to 40 degrees provides a second angle
From my own experience, the rear angle α is obtained with a deviation of +/- 2 degrees, which is quite enough.
