Finish brush sanders

The patented ROBA Tech principle is used for grinding flat and profiled workpieces.

The rotary brush belt grinding system for optimal processing in:

• Intermediate paint sanding
• Fine sanding
• MDF rough cut
• Sheet metal deburring

For these areas, ROBA Tech offers the optimal conditions for the best surface quality with its innovative grinding process.

The sanding process

The starting point for the patented grinding principle of ROBA Tech is the main disadvantage of all previously known rotary brush grinding machines: The usual machines working with grinding rollers only touch the workpieces in a very narrow area. A grinding process only takes place at the vertex of the circumference that the tool describes. The innovative ROBA Tech 1300 is equipped with a newly developed grinding brush belt with exchangeable grinding segments, which makes it possible to achieve a grinding surface of approx. 1300 x 1500 mm and more than 250 meters of grinding media. This is unique on the brush grinding machine market. A 360° rotation of the abrasive brush belt enables this machine to gently reach all corners of the workpiece. The reinforced disc unit is new, which can now also be used for light structuring and calibration work. To do this, it is arranged at the machine infeed and adapted to the task by using special disc tools: discs with wire strands are used for structuring, regardless of the grain of the wood.

The flat Micron Disks are used for sanding flat surfaces and ensure a chaotic sanding pattern that can be more easily covered by a top coat. Conical discs make it easier to sand edges and V-shaped millings, as the sanding brushes inclined at an angle can better reach the milling contours. In order to be able to use Micron or conical discs, it makes sense to install the disc unit at the machine infeed. The subsequent high-performance ROBA Tech sanding belt then takes over the final fine work.

At the machine outlet, many customers choose a double brush unit, which makes the ROBA Tech even more flexible when switching back and forth between solid wood and lacquer sanding tasks. There is also the option of designing this unit as a cleaning station.

The intensive grinding of the ROBA Tech unit needs a very good vacuum in order to also hold small parts securely. An MB-typical design of the vacuum channels ensures that an optimal holding force is generated with minimal vacuum fan performance.

Many grinding options that can be set via PLC help the operator to set the machine to their sanding requirements.

Advantages of the ROBA Tech principle

• Large grinding areas enable low movement speeds with better effectiveness.
• A 360° rotating grinding head with a large grinding area ensures even grinding in all workpiece areas.
• Freely programmable grinding parameters to optimize the grinding results.
• A perfected vacuum system guarantees the safe processing of small parts such as drawers.
• A “pulling” grind avoids wavy surfaces and also grinds deeply milled contours.
• Long sandpaper service life, since the low movement speeds prevent hard edge attack that increases wear.
• Optional additional units such as the disk system or the double brush optimize the result.
• Freely selectable abrasive configuration from the MB Flex system

The inexpensive alternative in the field of brush grinding machines is designed for the following areas of application:

• Intermediate paint sanding
• Fine sanding
• MDF raw sanding
• Light structuring work

The sanding process

The starting point of the ROBA Profi Brush sanding principle is sanding in the same direction and then in the opposite direction: Only this procedure guarantees that standing wood fibers are cut off in any case, regardless of the fiber direction of the material, be it wood or MDF.

In the basic version, the machine has two sanding rollers with a pressure roller system and in this version represents the solid basic equipment for every user who is striving for an optimum price/performance ratio.

Due to the modular structure, the ROBA Profi Brush series can be expanded with other systems such as disk, cross belt and cleaning units.

A vacuum system can be provided as an option for small workpieces. If the customer wants maximum ease of use, the unit positions can be approached by motor.

A machine with a cross belt unit is available for use in painting lines. Here, the aggregate constellation has been kept very compact in order to enable very narrow 370mm pressure roller spacing. In this way, even complicated workpieces with a small vacuum area can be transported safely.

An optional cleaning unit at the end of the machine includes a special brush and is equipped with an ionizing bar and blow-off system.

Advantages of the ROBA Profi Brush principle

• Climbing and counter-rotating improves the result.
• Pressure rollers securely hold workpieces larger than 370 mm.
• Vacuum transport system for small workpieces optionally available.
• Best offer for small investments.
• Frequency-controlled adjustment of grinding rotation and feed.
• Freely selectable abrasive configuration from the MB Flex system.

The Roba Profi Disk principle is used for grinding flat and profiled workpieces. The machine is designed for the following areas of application:

• Intermediate paint sanding
• Fine sanding
• MDF raw sanding

The sanding process

Many possible combinations allow the user to put together a ROBA Profi Disk for their specific application.

A double brush works in the same and then in the opposite direction: Only this procedure guarantees that standing wood fibers are cut off in any case, regardless of the direction of growth of the wood. The Profi Disk system then grinds the workpiece down to the last detail. This is made possible by the 3-axis disc system kinematics, which is a special design by MB: four 200mm disc grinding tools, each with 14 grinding strips, rotate around themselves. These in turn are mounted on three large master discs, which also rotate. In addition, the entire unit oscillates back and forth. All axes are individually adjustable. This allows the grinding optics to be significantly influenced. The kinematics are based on a grinding process with an eccentric grinder and guarantee a uniform surface structure.

The reinforced disc unit is new and can now also be used for light structuring and calibration work. To do this, it is arranged at the machine infeed and adapted to the task by using special disc tools: discs with wire strands are used for structuring, regardless of the grain of the wood. The flat Micron Disks are used for sanding flat surfaces and ensure a chaotic sanding pattern that can be more easily covered with a top coat. Conical discs make it easier to sand edges and V-shaped millings, as the sanding brushes inclined at an angle can better reach the milling contours.

An optional cleaning unit at the end of the machine includes a cleaning brush specially made for this purpose and is also equipped with an ionizing bar and blow-off system.

In the basic configuration, the encapsulated machine has a pressure roller system. For small workpieces, the machine can be expanded with a vacuum transport, and motorized height adjustment of the units can also be ordered.

Advantages of the ROBA Profi Disk principle

• The grinding behavior corresponds to that of a manual orbital sander
• Optimum “blurring” of grinding marks
• All workpiece corners are safely ground out
• The disc unit is equipped with a tool-free quick-change system
• Manifold variation possibilities in the machine configuration
• Freely selectable abrasive configuration from the MB Maschinenbau Flex System

The newly developed ROBA Big brush grinding machine with its 630 mm grinding roller diameter is designed for the following areas of application:

• Intermediate paint sanding
• Fine sanding
• MDF raw sanding

The sanding process

The starting point of the ROBA Big grinding principle is the main disadvantage of all previously known brush grinding machines: The usual machines working with grinding rollers usually have a brush diameter of approx. 310mm. This means that they only touch the workpieces in a very narrow area, around 30mm wide, because the grinding process only takes place at the apex of the tool. To compensate for this, these systems require high rotational speeds. However, high speeds lead to undesirable hardening of the abrasive, which leads to aggressive removal of the workpiece. The result is damaged edges and sanded surfaces.

The innovative ROBA Big is equipped with a newly developed, extra-large grinding brush diameter of 630mm, which makes it possible to expand the contact area with the workpiece to approx. 300mm. The increased number of slots allows more than 500 meters of abrasive to be installed, depending on the machine configuration. This is unique on the brush grinding machine market.

In this way, it is possible to achieve high cutting speeds at low speeds and thus significantly increase the grinding effectiveness. The increased contact area and the gentle attack on the surface to be treated guarantees the best results. Low movement speeds of the sanding segments ensure that the sandpaper does not jump over the milled workpieces. The grinding system enables you to slide into the recesses and grind them out effectively.

Many grinding options that can be set via PLC help the operator to set the machine to their sanding requirements.

In particular, mass manufacturers or users with fast-running surface lines benefit from the ROBA Big principle.

Advantages of the ROBA BIG principle

• Large quantities of abrasive enable intensive processing of the workpieces, while at the same time the abrasive has a long service life.
• A large diameter ensures effective grinding in all workpiece areas.
• The contact area with the workpiece increases to 300 mm.
• A perfected vacuum system guarantees that even small parts can be held securely.
• Low rotation speeds increase abrasive life.
• Freely selectable abrasive configuration from the MB Flex system.