Friday 22 June 2012

Professional Weather Forecasts

Something light for the midsummer weekend: In spring we visited Bremerhaven, Germany, where there is the "Zoo by the Sea" ( Definitely worth seeing, and on that day it was especially nice, because we went in the middle of the week, the sky was grey, it had been raining earlier, and it was only some 10°C. But the result: we were almost alone, could see everything easily, and there was no stress on the great playground.

For the atmospheric scientist, never mind the animals, they offered an intriguing weather monitoring system! The sign underneath explains how it works:

  • Stone has a shadow – the Sun is shining.
  • Stone is wet – it's raining.
  • Stone is hardly visible – it's foggy.
  • Stone is white – it's (been) snowing.
  • Stone is moving – it's windy.
  • Stone is swinging heavily – it's stormy.
  • Stone is under water – there's a flood.
  • Stone has fallen down – there's (been) an earthquake.
  • Stone is gone – there's been a theft.
I'm seriously considering of installing such a smart weather station at our observatory, too...

Have great midsummer weekend!

Photo: Thomas Ulich; click for a larger version.

Thursday 14 June 2012

Project Doll's House: Let's build it!

Now then, let's make it, and find out, if the theory is any good in practice. In the previous post, there's a list of elements to cut out, and a suggestion in which order this could be done. The first step is to cut the ground plane, the rear wall, and both side walls. I suggest to leave the side walls rectangular at this stage, since it is time-consuming to cut the exact roof shape only to find out that something else went wrong. Therefore I really recommend to leave the roof until all the other bits fit together – contrary to what I did and what is shown in the photos.

After cutting out these four elements, 5 mm deep grooves are cut into the ground plane, into which the walls will be seated. Now we can make a first test and see if everything fits together so far. This also serves as a motivation boost for you and most importantly for the little girl waiting for her doll's house: "Daddy, you can REALLY do that!"

The next step is to cut out the two floors, and to cut grooves into the side and rear walls to receive the floors. Again, it's time to try the arrangement immediately, just to see how the project takes shape.

The next step is to cut out the interior walls, and then make the grooves for them to sit in. Apart from working out the exact shape of the roof for the folding mechanism, this is the trickiest bit, because it requires – even more than before – precision measurements and work. In the photo above, the interior walls already have doors in them. The doors and staircase will be explained in the next post.

I did not manage to get all grooves exactly lined up, and an offset of a few millimetre is visible in the front between the first-floor wall and the second-floor walls. Since a lot of effort and time went into this, and the winter was fast approaching (I have to do these things outside!), that we decided to leave it at that and not try to redo the lower floor and the ground plane.

The final result looks already a lot like a doll's house, with expectations and excitement clearly on the rise – and Christmas on the horizon! At this point it's worth mentioning, that the house in the picture above is held together by exactly two small nails on the upper rear corners of side and rear walls. Everything else just slots into grooves.

Now that we are at a stage that all major elements are cut out and everything fits together well, it is time to cut the top bits of the side walls into the proper shape for the roof and to cut out the doors and elements for the stair cases. Then it'll be time to plan size and location of the windows. Finally, the whole thing will have to come apart for painting. To be continued...

Photos and design: Thomas Ulich.

Sunday 10 June 2012

Project Doll's House: Summary of Measurements

After so much theory and thinking, maybe it is time to make a simple summary list of the elements we need to cut. If you trust your planning, you can now cut all at once, but maybe it is wise to cut and groove only some parts, and then see if everything fits, before cutting more.

However, we first need to finish some missing bits of the theory, we need to determine the overall height of the doll's house. Previously, we discussed the height of the rooms, and the roof-folding mechanism. All of this we need to put together now, in order to work out the height of side and rear walls.

First, let's decide here, that the ground plane will have 5 mm deep grooves to receive the side and rear walls.

The rear wall needs to cover two floors of 200 mm each, which we said should include the thickness of the floor element (9 mm), i.e. the free room height will be 191 mm. Thus two floors need 2 x 200 mm = 400 mm wall height. To this we need to add 11 mm as detailed earlier, and we need to add another 5 mm to account for the bit the wall will sink into the floor. Thus the rear wall will be 416 mm tall and, as determined previously, 782 mm - 2 x 7 mm = 768 mm wide (7 mm for grooves in both side walls).

The side walls are a bit more complicated, but let's first only cut out two rectangular pieces of wood, after which we will transfer the measurements of the roof-folding mechanism to these elements and cut out the details in another step. The side wall needs to have the same height as the rear wall up to the point, where the roof section starts, i.e. up to the place from where we will later make 45° cuts. Thus we know that the lower bit is 416 mm tall (see above). From the post about the roof-folding mechanism (drawing), we can see that the height above that line is 180 mm + 12.7 mm + 20 mm = 212.7 mm, which gives a total height of 628.7 mm. Previously we already worked out the width of the side wall to be 360 mm.

Now then, here's the list:
  • Ground plane, 12-mm plywood, 420 mm x 842 mm (from here)
  • Side walls, 12-mm plywood, 360 mm x 628.7 mm (2 pieces; see above)
  • Rear wall, 9-mm plywood, 768 mm x 416 mm (see above)
  • Floors, 9-mm plywood, 764 mm x 354 mm (from here)
  • Internal walls, 9-mm plywood, 197 mm x 354 mm (from here)
Thus a practical approach is:
  1. Cut ground plane, side walls, rear wall.
  2. Make 5 mm deep grooves in ground plane for the outer walls, side walls 12 mm width, rear walls 9 mm.
  3. Make grooves along the rear edges of the side walls, so that side and rear walls overlap as shown here.
  4. Put it all together. This is always a motivating highlight. Repeat often.
  5. If ok so far, copy the outline of the roof-folding mechanism onto the side walls, and cut out accordingly.
  6. Put it all together.
  7. Cut floors.
  8. Make 3 mm deep grooves in side and rear walls for floors, make sure they align properly.
  9. Put it all together.
  10. Cut interior walls.
  11. Make 3 mm deep grooves for interior walls.
  12. Put it all together.
After all this you should have:

In the next post, I will show the build stages outlined here.

Design and photo: Thomas Ulich.