Abrasives expert Suhner (Australia) presents an objective comparison of tools with flexible shaft, power tools, and pneumatic tools to show economical and efficient machining on surfaces with aggressive abrasives and long duty cycles.
Tools with flexible shaft
Designed for heavy duty applications with a flexible shaft that decouples the drive motor from the tool in the user’s hand, these tools deliver lower vibrations and fatigue, and greater safety, with the speed regulated either continuously or via presets. The user can therefore utilise a combination of powerful drive output and lightweight hand piece. Advantages also include low noise levels, high torque, and potential reduction of workspace needs.
The comparison was made with the tried and tested ROTOfera featuring a three phase 400 V electric motor and an FSM angle hand piece.
Driven by a powerful single phase universal motor, these tools offer advantages such as compatibility with the ubiquitous single phase mains; digital constant electronics with starting current limitation, overload and undervoltage protection; ease of handling; and compact design for outstanding manoeuvrability.
The comparison was made with the compact UWG 10-R angle grinder.
Thanks to their multidisc motor, these tools are highly robust, easy to service, powerful, and lightweight. Providing high reliability and operating safety, these motors can withstand overloading without damage, even when stationary.
The comparison was made with the highly manoeuvrable, lightweight LWG 12 angle grinder.
All three tools were fitted with a new, identical roughing wheel 125mm in diameter. Operating time per tool was 3 x 3 minutes with three users. The machined material was X5 CrNi 18 9/ 1.4301. Speed was optimised to the abrasive for the best possible removal of material while equally high and constant contact pressure was maintained.
A material removal rate of 500 g/h corresponds to a typical industrial application that includes factors such as fatigue. An eight-hour shift therefore removes 800kg of material over 200 working days each year.
Findings, assessment, and conclusion
Key findings from the comparison: Overload protection on the UWG 10-R power angle grinder switched to cooling mode just before the end of the comparison; the UWG 10-R power angle grinder exhibits 50% greater wheel wear and the LWG 12 pneumatic angle grinder delivers a performance nearly equal to its competitors.
The tool with flexible shaft continues its status as the unchallenged powerhouse. When a lot of material has to be removed over long periods and there is available working space, this tool presents a highly convincing economical solution.