There are two different models of the SOLO tool, the SOLO and the SOLO 2. Each tool is capable of reaching counterbore sizes two times the bore diameter minus 1mm. Possible applications up to 30mm through hole. (Max ratio = Ødx2 - 1mm).
The SOLO uses two centrifugal weights installed in a sealed tool head. With an activation speed rate of 1900 rpm, the weights start moving outwards and turn the gearwheel. The gearwheel drives the blade out by rotating the blade control. When the spindle is stopped, a pull back spring pushes the centrifugal weights back to the center and retracts the blades.
The SOLO 2 uses similar parts, but works in the opposite way. With an activation speed rate of 2000 rpm or higher, the blades retract when the centrifugal weights move. When the spindle rotation is below 1500 RPM, the weights are pushed back to the center and the blade is fixed in the cutting position.
Optional: SOLO S2, a larger SOLO head (blue ring) may be used for bores larger than approximately 22mm
Fig. 1: Spindle stopped: SOLO → Blade retracted; SOLO2 → Blade extended
Fig. 2: Spindle rotating: SOLO → Blade extended; SOLO2 → Blade retracted