Lad-100.K5 - a Tool for Sharpening Drills and Mills
Well-sharpened drills drill 3 ... 4 times more.
This device is installed on the Lad-100 milling tool and is used in conjunction with a Dremel-type rotary tool.
The device is designed for sharpening spiral drills with a diameter of 3 mm to 10 mm, as well as end mills with a diameter of 2.4 mm to 3.5 mm. (And for smaller drills there is Wishbone 2)
Used grinding discs are available and inexpensive. The device itself is quickly assembled, configured and very easy to use - just set the sharpening angles according to the red marks and the drill will be well sharpened in most cases. And if you need to process aluminum, stainless steel, composite material, etc. - you can set to set the angles recommended for such a material, and also sharpen the drill correctly.
Drills and cutters can be sharpened by the following methods:
1. Single-plane sharpening
2. Two-plane sharpening.
You can also remove the occipital part of the tooth and undercut the main and transverse cutting edges with an increase in the front cutting angles on the transverse edge.
Made Lad-100.K5 - a Tool for Sharpening Drills and Mills or STL files and instructions for self-production you can find via the feedback form.
Lad-100.K5 costs $ 16.
The cost of international delivery by post of Ukraine approximately $ 12.7.
The device kit includes:
1. guide with carriage,
2. long prism (for long drills),
3. short prism (for short drills),
4. emphasis for drill bits,
5. prism for end mills,
6. emphasis for end mills.
Notes:
1. The scale for setting the angle of the apex of the drill is marked for angles 90 °, 118 °, 140 °, 180 °. 118 ° angle are highlighted in color
2. The scale for setting the rear grinding angle is marked from 5 ° to 50 ° in increments of 5 °. angles of 10 ° and 35 ° are highlighted in color.
The assembly and adjustment of the device, as well as the process of sharpening the drill and test drilling are shown in the video:
Recommendations for working with the device:
The sharpened edge of the drill must be installed parallel to the movement of the tool carriage. This is conveniently done using an auxiliary line on the surface of the grinding disc. To draw a line, you can install the marker in the prism, press it to the surface of the disk and move the carriage from the center of the disk to the edge to draw an auxiliary line. Then install the drill into the prism by turning it so that the sharpened edge is parallel to the auxiliary line.
Recommendations for flat sharpening drills.
Single-plane sharpening (Fig._1a) is mainly used for small drills with a diameter of less than 3 mm.
The back surface of each blade is formed by one plane. In order for the end of the blade not to abut against the bottom of the drilled hole, the rear angle in the cylindrical section should, as a rule, be at least 28–30 °, which creates a danger of chipping of the main edges. The transverse edge of the drill is straight and perpendicular to the axis of the drill.
For single-plane sharpening on drills with a diameter of more than 3 mm, the angles a1 = 8 - 12 °, the occipital part of the tooth is removed (Fig ._1b).
Two-plane sharpening (Fig._1c) is a combined method, since each of the two planes forming the back surface of the blade is sharpened separately. The intersection rib passes through the axis of the drill and is usually parallel to the main edges. The transverse edge of the drill consists of two inclined lines with a protruding center point, which improves the work of the drill at the initial moment of cutting and increases the accuracy of drilling.
Fig._1. Drills sharpened on the planes: a - one at a time, b - one at a time with the removal of the occipital part, c - two.
The rear corner of the first plane is selected depending on the material being processed. The rear angle of the second plane is taken within 25 - 40 °. The larger the angle, the less axial force and higher drilling accuracy. However, a sharp slope of the second plane reduces the stiffness of the blade, weakens the cutting wedge, and degrades heat dissipation. When drilling materials of medium and low strength, drills made of high speed steel have an angle a2 = 35 - 40 °. High-speed drills when drilling high-strength materials, as well as carbide drills for all materials, have an angle a2 = 25 - 30 °.
Cuting the main and transverse edges, provides improved drill performance, durability and accuracy of drilling.
The transverse edge must be cut off for all drills intended for processing high-strength materials, carbide drills, as well as for drills having a core diameter K≥0.18D. For drills with a thinner core, working on materials of medium and low strength, after two-plane sharpening, it is not necessary to cut the transverse edge.
The Lad-100.K5 tool allows you to cut as shown in the figure on the left. This type of undercut differs in that the chip discharge groove passes directly through the transverse edge, which gives an increase in the front angles on the transverse edge from –50 ° to 0 °.