The Belt Sander
Belt sanders work as follows: The belt-shaped abrasive is guided over two rollers at high rotational speed, one of which serves as driving roller for the sanding belt. The other roller has an adjustable bearing to adjust the belt position precisely. The belt sander base between the rollers is a rigid, but heat-insulated footplate, which serves as pressure pad for the sanding belt.
Characteristic properties of belt sanders
The most important feature of belt sanders is their linear sanding motion, which always runs in the same direction, and the high rotational speed of the sanding belt. The linear sanding motion is ideal for materials with preferred direction (fibre orientation in natural timbers). The high rotational speeds of belt sanders ensure good work progress. The belt sander is recommended for the processing of plane surfaces. However, in case of sharp corners and edges, convex or concave surfaces, there is a risk of local oversanding due to the straight and hard sanding pad. Premature wearing out of the sanding belt can be another consequence.
Removal rate of belt sanders
In addition to the grit of the abrasive, the belt speed determines the sanding performance. The processing of materials with preferred direction such as wood increases the removal rate across the grain, however, the surface quality deteriorates. Sanding with the grain reduces the removal rate, but improves the surface quality considerably.
Processed materials
Handheld belt sanders are mainly used to process natural wood and wood-based materials. On metal surfaces, the removed material is pulled across the entire length of the sanded surface, producing furrows and draglines. This will also occur on plastic surfaces, but additionally the sanding dust will melt through the frictional heat and reduce the surface quality further. The same applies to varnished surface.
System accessories for belt sanders
Belt sanders can be equipped with the consequences system accessories:
• subframes
• sanding frames
• dust collector
• Bosch Microfilter System
• dust extraction adapter
Subframes
Subframes are designed for the stationary application of belt sanders and compact belt sanders. They are equipped with adjustable limit stops for longitudinal, diagonal and angled sanding.
Sanding frame
Sanding frames are the most important system accessories for belt sanders. By pre-selecting the sanding depth, they can be used for the level sanding of large surfaces.
Dust collector
Canvas or paper bags are the classical dust collectors for belt sanders. The advantage of canvas bags is that they can be reused, however, they allow relatively much of the potentially dangerous fine dust escape through the fabric pores. The pores of paper bags are much finer and are therefore more effective in retaining fine dust particles. They are designed as oneway
bags and cannot be reused.
Adapter for external dust extraction
External dust extraction is more effective than most other methods; however, a separate suction appliance is required for this purpose. All Bosch belt sanders are equipped with dust extraction ports to connect them to a vacuum cleaner with the help of an adapter.
