Staircase handrail from Switzerland
Swiss woodworker creates flowing wooden handrails.Woodworking company Bietenholz + Müller in Wil (Switzerland) offers a wide range of wooden products, both standard and custom made. Last century they started as wood turners, the addition of CNC machining to the set of tools resulted in a versatile company.
From the company website - "Drechslerei und Holzwaren" translates as "Turnery and Woodwork".
One of the specialties of Bietenholz + Müller is creating handrails for staircase wells: staircases that spiral round an open space (a well) over multiple floors. Such staircase well needs one very long handrail with complicated curves: much too long to be made in one piece. Bietenholz + Müller creates the separate sections for these handrails on their large rotary CNC machine, using DeskProto to calculate the toolpaths.
Four DeskProto screenshots, showing the geometry (in a cylinder shaped block), roughing toolpaths, finishing toolpaths and the simulation. Click on each image for a larger view.
As you can see in the four screenshots above, Bietenholz + Müller have used pyramid shaped support tabs, to minimize manual labor after removig the tabs. For the same reason finishing is done with a very small toolpath distance, using strategy Crosswise (so running parallel toolpaths both along X and around A, for a very smooth resulting surface).
The simulation shows a preview of the result, making it easy to check if the cutter will indeed reach the complete part.
Suitable for large parts: max part length 3700 mm
This very large machine is the Hapfo 7000-CNC, made in Germany. The manufacturer in 2020 merged with Steinert Drechselzentrum Erzgebirge. The machine looks like a very large lathe, however when you look more closely you can see that a (horizontal) spindle motor is present (above the orange part), on a CNC controlled horizontal axis. So the machine can be used both as a lathe and as a 3-axis CNC milling machine. The horizontal axis on the machine in DeskProto is the Z-axis.
On this machine one more axis is present, which is manual: the position of the motor on the vertical column. In this project it has not been used.
A similar curved part of a complex handrail being machined.
The photo above is taken from the back side of the machine, so you can see the spindle motor and the cutter at the top of the image. The curved part that is being machined is not the same as in the DeskProto screenshots. The photo is taken while finishing: right the result after roughing, left the result after finishing. You can see that a very thick roughing skin has been applied.
All separate parts will be assembled to form one long flowing handrail. The result of a recent project is shown below.
Villa Rosau in Zürich.
One of the most iconic buildings at the Zürich lakefront (Switzerland) is Villa Rosau. It was built by architect Ferdinand Stadler in 1845, at that time named "Seegarten" (garden at the lake), outside the city walls.
A complete renovation of the Villa has been achieved between 2017 and 2020. An important requirement for this renovation was to preserve the charm of the villa with its style-defining details. This is why the clients have contracted Bietenholz + Müller to finish the villa's central stairwell. Applying up-to-date technology they created a result that matches the required nineteenth century style and quality.
The finished handrail in the central stairwell.
The images above show the result: one long flowing curve as handrail over all floors. Though it has been built from many separate pieces the result is one smooth rail: a true showpiece for the craftsmanship of Bietenholz + Müller.