Jan 082020

In order to create an accurate plan of an old house, I purchased a Leica X4. It is a robust, pleasant instrument, clearly designed by engineers, for engineers and the build quality is faultless.

My first pleasant surprise was that each device is comes with an individual calibratation certificate and the tolerances are much tighter than the blurb in the spec-sheet:

As it should be, the deviation tolerance (±2σ) is supplied at a specified temperature, with tolerance (±3°). Second pleasant surprise, 0.2mm at 7.8 metres is 0.002% – this is clearly a laboratory-grade instrument.

Indoor measurements are made with the red laser dot, outdoor measurements can also be made using the builtin zoomable camera, both very intuitive

The quick-start guide is about as terse as can be – essentially useless for more than using the device as a tape measure – you’ll need to download the manual to be able to make use of all the X4’s features; it is well-written and easy to follow. It took me a good half-hour to become capable of making every measure possible, they are extensive:

  • Room area and volume, corner maxima, wall width from 3 points
  • Angles and resulting line projections
  • Indirect object height from measure-to-base and altitude angle (to measure the height of a tree without a laser dot on the top branch)
  • Stake-out
  • Min-max measures
  • Bluetooth connection to Android phone to transmit values
  • … and so forth

In a nutshell, the X4 can measure (or deduce using Pythagoras), almost any measurement you can imagine and it does it quickly and precisely.

The indirect height function was disabled as-delivered, I had to download the firmware update to my Android and flash it to get this to work (I tested it against known targets and it works extremely well). Aside from firmware updates, this “DISTO Plan” program offers several plugins for plans, facades and room layouts. The interface is clumsy and the advanced features are payable. Disappointing.

Verdict: The X4 is a gem of precision Swiss engineering that is a delight to use and of extraordinary accuracy; just delete the Android software once you’ve used it to flash the latest firmware.

Nov 022014

Bird House by Claude Nicolas Ledoux

(click any picture for full-size view)

10 years ago, Nicolas and I built a swiss-chalet style bird house:

Swiss chalet bird house

A decade of rain and snow had taken their toll, so this summer we decided to build a new one.

Some years back we visited the Royal Saltworks at Arc-et-Senans and were so bowled-over by Claude Nicolas Ledoux’s architecture that we bought the book of his plans and Nicolas came up with the idea of using one of his designs. We settled for a simple Abreuvoir et Lavoir (trough and washing-room):

Abreuvoir et Lavoir

The full-sized building was about 9.7 toises wide, which is just under 19 metres. Our first attempt was scaling 25:1 but we were constrained by the beech planks we wanted to use that were 18mm thick, which would have made the walls too thin, so we finally decided on 29:1. We imported the image into Visio and created a custom scale so that the dimensioning shapes would show the measurements directly in the final units:
Abreuvoir et Lavoir

We respected the design as faithfully as possible, the only change being to remove the four columns at the front, as we felt that the birds would shy away if they were too closed in.

It quickly became clear that the sculpted walls and columns were going to be tricky to execute, so we created a 3D model:
Shaded 3D

which helped greatly to plan the grouting:

Grouting Wireframe

Experience had taught us that our worst enemy was water, so we assembled entirely with glue and dowels. For easy maintenance, the floor has aluminium posts sealed with epoxy resin that the house drops onto:
05 Bird House
and the walls are slightly raised from the floor to prevent water lying under them.

The floor and roof were tar-painted and covered with roofing felt. The feeders are in aluminium:
04 Bird House

The roof slots over the walls, with latches to prevent it from lifting in the wind:
06 Bird House

and the entire assembly sits atop a 2-metre post:

02 Bird House