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Friday, 24 April 2015


We needed a new pair of sofas, as the old ones were cast-offs that were worn out and collapsing. So, I decided to make some. The square design was settled on, in a size that fits the spaces we have available.

More storage is never a bad idea and I never liked the wasted space that sofa take up, so the space under the seats was designed to store stuff.

The frame is simply boxes of plywood on a wooden frame:

Foam is stuck to the outside surfaces and then covered with material, which gives a firm seat. here's a covered arm:

Everything bolts together and has been sized so that the TV unit I made can be slotted in where a seat would be, on either of the two sofas. So, we can swap sides by swapping one of the seats between sofas. The arms just bolt on the end of whatever they need to.

Here's a finished sofa:

Unfortunately the material choice was a bit unsuitable, as the material pills easily and catches a lot of debris, so a recovering exercise may be in my future...

Hexagonal Lampshades

There's currently two bare light bulbs in the main bedroom, so a plan came about to create some lampshades for that room. There are two ceiling roses, and the plan is to create two hexagonal glass and copper shades. The glass chosen is a rippled purple glass (English Muffle, I believe).

The sheet was first cut into two parts:

Then, gradually the parts for the hexagons was cut from each half:

I used a template to mark out the hexagons and the sides:

The cut the appropriate shapes out:

There's six bulbs in each hexagon, so I needed a way to mount the bulb holders. This is where 3D printing comes in handy, as the holder is a simple thing to make on the printer, as it has an obvious flat surfsce to print from and there's no overhangs.  The angles will all be accurate and although the 3mm holes had to be drilled out the final item is very neat:

The bulbs and bulb holders mount on the end of each finger:

The hexagons are assembled using copper sheet soldered together with a copper wire frame inside the hexagon to hold the glass in place in the copper sheet frame. The internal frame also provides a way to mount the star bulb holder.

Once mounted in the hexagons the bulb holder also holds the central bulb holder which is modified to attach to the wiring of the star bulb holder.

The final hexagons look like this when they are in place:

Tuesday, 21 April 2015



My old belt was falling apart as it wasn't fully leather, but a man-made composite, so I decided to make a new one.
The result looks good, it remains to be seen how well it stands up to daily use. I made the holes very specific to where I want them, so this isn't a belt I can lend to anyone...

The belt itself was a strap of black leather that matched the old one in width, so I could re-use the buckle from the old belt. The buckle was riveted onto the belt, which is different to the old belt as that was stitched.

The rivets also hold the loop for the belt, so there as four in total.

So far, it is working well.

Wednesday, 15 April 2015

Dehydrator MK 2

After success with Dehydrator MK 1, I decided that the cardboard box would probably give out after a while, but before that happened the supply of 100W light bulbs would run out. Several bulbs failed and they are now difficult to buy, so I decided to build a more solid solution.

I'd need a heat source, a fan, and something to control it all. In the end I added a temperature sensor and a humidity sensor, and attached an LCD panel that I had hanging around. An Arduino Uno controls everything.

The power for all the circuitry comes from a slightly modified power supply PCB from an old video recorder. I modified a couple of supplies to get 12V and 5V and added voltage control from one of the Arduino PWM ports so that I could control the fan speed using firmware.

Video recorder PSU PCB

The electronics is in a separate area to the drying chamber, with a hinged front panel to allow access.

The arduino and the display are on one panel:

The fan and power supply and the power resistor controller are on a second panel:

The heat source I settled on was a 200W wire wound resistor that was connected across the mains supply using a triac with an opto isolated trigger from one of the Arduino GPIO lines. The algorithm works on a 30s cycle, altering the duty cycle of the power drive between 0% and 100%, in order to get different power outputs from the power resistor.

I also added an I2C temperature and relative humidity sensor so that I can attempt some form of automation in the future. All the power settings and readouts from sensors fits on the LCD display:

The trays fit in from the top (something I may change in a dehydrator MK 3, as it's a bit fiddly but it does make the air flow easier) and are wooden frames with plastic mesh on them.

I've dried apple, tomatoes and mango in the drier so far and the results are pretty good, I can't tell dried mango from the dehydrator from shop bought dried mango.

Oh No! Hinge Failure

It looks like there was a problem with the hinges in the pen box. The nails were just too short to hold the hinges when the box lid was twisted. Solution: Bigger nails. Screws would have been nice but I didn't have any of the right size and it would take too long to order them.

You can see the bigger nails here:

It seems sturdier now...