Category: Uncategorized

Folding kitchen steps

Posted on by pica

We needed some steps for the kitchen since our cupboards are really high. However, we’re a bit short on floor space, so I wanted something that could fold away and not take up too much room when we weren’t using it. Not finding anything like that on the internet, I made my own plan in SketchUp and set about building it.

Here’s the first cuts of the sweet Chestnut ready for cutting into the parts which make up the stool.

After having run the pieces through the planer and thicknesser, I glued some of the more complicated pieces. Here, you can see the pair of sloped edges. Clamping them as a pair meant I could set the clamps against parallel edges.

This is the glue-up of the two pieces which make up the sides of the part which swings down. Their shape is a bit complicated because they have to fold into the upper steps. Again, gluing them as a pair meant I got nice parallel surfaces for the clamps.

I used my router to create the rebates in the sides (here are the two base edges held in place together to minimise the likelihood of tear-out).

Having milled all the pieces, I did a quick dry-run to see whether things fitted as I expected. In general, everything looked good.

Here’s the dry-fit with the steps in the “stool” configuration. The footprint of the steps when they’re folded like this is only 41cm wide by 27cm deep. They height of the final stool is also just right for resting on whilst waiting for something to cook.

Gluing up the bottom section…

and the top section.

Checking things fit together as expected once glued together.

As it turns out, not everything was quite right, so I had to shim this step to make up the difference.

I felt the steps weren’t going to resist racking too well, so I added this diagonal brace to provide better rigidity.

Adding the hinges. I looked for sprung hinges that would have made the top come down gracefully, but they were all too big for this project.

Hinges in and the first of three coats of varnish going on. I lightly sanded between coats with 1500 grit to remove small blemishes.

Steps stored in their stool configuration, taking up a relatively small area.

Here’s the steps unfolded and in use.

Virgin Broadband Update

Posted on by pica

Following on from my last post about Virgin Broadband and their traffic management, I came to a realisation. I phoned them up and asked about the current usage for our account over the last few weeks or so. They gave me this data:

Daily Downstream Total:
Period Total (GB)
26/03/2011 0.432 GB
27/03/2011 0.362 GB
28/03/2011 0.748 GB
…
17/04/2011 0.591 GB
18/04/2011 0.863 GB
20/04/2011 9.496 GB
21/04/2011 9.912 GB

What is apparent is that around about the 18th of April, our usage dramatically increased. I couldn’t account for this usage in general browsing terms, especially as we were away for a few days over that period. Thinking back, I looked over the iperf commands I was using to measure the bandwidth. On the client side, I was running this command every ten minutes:

iperf -c www.example.com -P 4 -f k -w 256k -t 60

This was using a TCP window of 256k, a transmit window of 60 seconds and four threads in parallel (-P 4). The net result of this is that I was sending 70MB of data from the client to the server six times an hour. Multiply this by 24, and you get a number very close to 10GB (which is what Virgin indicated we were downloading). So, after a bit of reading, I changed the client iperf options:

iperf -c www.example.com -P 1 -f k -t 5 -x CMSV

Now, I only have one thread running for five seconds with a default TCP window length and a single thread. The addition of -x CMSV reduces the output from iperf and means I don’t have to grep SUM to get the relevant line. Furthermore, I think a 10 minute sampling frequency is a little on the high side, so I changed the cronjob to only run the iperf script every half an hour, which should still give the granularity I wanted.

Of note is that with a smaller TCP window and a shorter transmit time, the results are slightly more erratic. They are, however, still showing the same pattern as before.

So, it seems Virgin were correctly measuring our downloads and managing our traffic accordingly. What caused the initial slow-down that prompted me to measure the bandwidth remains a mystery.