Koch Grinding Machine. Grinding and polishing.
The Koch 4004 is a simple and brilliant design. A grinding and polishing machine for the gouges and chisels of sculptors and wood turners.
The sharpening wheel on this machine is a CBN wheel. Every type of steel can be sharpened with it, except tungsten carbide. The advantages of a CBN disc are obvious. Less heat development and no more grooves in the surface. The grinding wheel always remains the same size. The handles for the wheel no longer need to be adjusted for this. The machine is a noun slow runner, 1400 RPM. The motor is a 300 W single-phase motor with a shaft that extends to the left and right of the motor. The windings are on this shaft and the pressure is absorbed by large ball bearings.
The burr that arises during sharpening can be removed on the felt discs. The two felt discs are enriched with aluminum oxide and made of special felt and differ in hardness. Soft felt discs for fast material removal and hard felt discs for even polishing. (The yellow disc is for round profiles and the green for straight, for example plug chisels.) A wood turner can keep his flat chisel sharp for a long time by just using the felt discs.
The supplied Koch grinding paste is grit 2500. There is also a paste grit 3500. This grinding paste also has self-cooling properties, making it possible to quickly sharpen tool steel tools without overheating them. The rods mounted in front of the machine are polished and 12 mm thick. This means that every attachment from the Tormek, for example, can also be used on this grinding machine. The most convenient of these is undoubtedly the SVD 186.
The special thing about this machine is that, while your chisel remains in the sharpening attachment, you can move from the stone to the felt disc. It goes super fast and the result is amazing. I wouldn’t believe you could “buff” away 80 grit grinding marks with polishing compound 2500. But it is, and it happens with unprecedented speed and ease! The guide rods are infinitely adjustable and can be securely fixed with a handle.
- 1 CBN disc (150x40mm, 120 Grit)
- 300W motor
- Felt disc 120x20mm (Can also be reordered)
- Felt disc 150x30mm (Can also be reordered)
- 1 Kg Koch polishing paste green, 2500 grit (Can also be reordered)
- handles for adjusting the guide rods
- plexiglass protective cover
In the video below, the Koch HT 4004 is compared to the Sorby Pro Edge, the bench grinder with CBN wheel and the Tormek T8.