Rudder design for Noux IOM

Finally decided to make some proper rudder moulds for the Noux. This design, based on the rudder a number of Noux boats have been using for 1-2 season, was chosen. It's a simple(based on a Marblehead rudder by Bob Sterne actually) moderately deep rudder with a fairly thin section (just enough to accomodate a 4 mm rudder stock).

Below some pictures from the CNC milling of aluminium moulds.
Continue reading Rudder design for Noux IOM

Testing VFD and AC induction motor


The stock 600 W DC motor on the CNC-converted Opti BF 20 burned out and had to be replaced.

Jari got a 750 W ABB AC induction motor to replace it and found this used VFD for driving it. Here we are testing the VFD for the first time and it seems to work OK. Acceleration and braking speed is great compared to the old DC-drive.

There's a normally-open start switch (black), a normally closed stop switch (red), an SPDT direction switch (blue), and a linear 10k pot (black) for adjusting the speed. Next step is to build a proper front panel for the switches. The VFD also has a 0-5 V load output which would be nice to monitor while machining.

I've started a new category, CNC, for everything related to CNC control and machines. Hopefully I'll have more to post about these things in the future...

Fixed problems with permalinks and stattraq/mostwanted

For a while now I have had the stattraq and mostwanted plugins installed. The idea is that stattraq logs statistics of how many users are visiting, which pages are popular etc. into a database. Then mostwanted picks out the most popular posts and lists them in the sidebar on the left.

Up until now I have only got the text "no results available" from mostwanted due to a problem with handling permalinks in stattraq. But today with some help from nice people on the #wordpress IRC channel I got it fixed. There are two things that need to be done.
Continue reading Fixed problems with permalinks and stattraq/mostwanted

Measuring the closeness of competition ?

I've been wondering if it is possible to measure the level of competition in IOM regattas. Here's one way to possibly do it. I've looked at the winning skippers net score and divided that with the number of races. So we can see that to win a world championship you don't have to win every race - an average score of around 4-7 will do !
The green dots are from various national championship scores I've found.
The red squares are nordic events - I see a clear increasing trend !
The blue dot's is our national Finnish ranking series - we see that there is still room for improvement.

Ofcourse this is not an ideal way of measuring the level of competition. If one single skipper takes command of most of the races the racing behind him/her might still be really fun... but I do think my plot shows something of the truth.

If anyone wants to send in results with the number of races sailed, the number of discards, and the winners points, I'd be happy to add them to this plot when I have time.

Update: Odd-Oivind Kure commented that what this really shows is not the level, but the 'closeness' of competition. That's true, so I've changed the title. (although from looking at the graph there definitely seems to be correlation between level and closeness).