Sunday, June 15, 2008

How does your rudder hang?

I can't believe its over 3 months since I created this blog and this is my first follow on post.

Sadly we only got our first sail in Poco Loco last weekend. Not the best of days weather wise and let down by my ability to tie secure knots! I've made quite a few changes made to her over the winter months but enough to warrant being 2 months late launching :-)

I will be tweaking the positions of various settings over the coming weeks and will post up some of the control set ups I am using.

Clearing out the garage today I re-located a spare set of the foils that came with the mirror. This got me thinking as to whether I was using the best set for racing. A thorough inspection yielded some interesting observations . The first one being that the re-found daggerboard was a laminated foil and lighter than the one I had used for the past 12 months. I think I will defintely give this a try next time we are racing.

Being the scientific type I also got the bathroom scales out. The results were as follows:
Daggerboard - old: 6.5lbs new: 5.5lbs
Rudder blade - old: 2.5lbs new: 1.75lbs

I have in the past heard people talking about the fact that the rudder blade hung vertically. So I set the boat up outside, levelled her and fixed the tiller centrally in position with my acme self steering system. My self steering system is a piece of elastic tied to the rear fixing point of the toestraps with a bowline tied in the other end. The bowline slips over the end of the tiller and keeps the tiller centrally positioned. This is ideal when I need to dash forward to sort something out when racing with the little one.

I then took the following pictures from the same fixed point and was very surprised by the results. The only thing that changed between the shots was taking the bolt out and sliding in the other blade.

So starting with the "old" blade:

And the "new" one:

Enlarging the "new" picture you can see where a previous owner has marked up the blade when its in the stock. You might be able to see a small black line underneath the stock and a sloping line marked with a "V" aligned to the rear of the stock. So a quick glance over the transom after launch will confirm whether the rudder blade is fuly down.

Other observations I made comparing the two were the "new" blade was noticeably thinner, with a less aggressive cross sectional shape. Now I need to pack out the "new" blade in the stock with cut down ice cream tub lids or old CD's. This should prevent it from twisting in the stock under load whilst sailing.

So the "new" foils will get an outing at the end of the month at the club regatta.

Being a Laser sailor I've not really had to worry too much about foil shape and how it hangs. Given you can't do very much other than reduce the thickness of the trailing edge.

So I assume from the above pictures, the "new" blade will create less drag and reduce weather helm. Any other benefits?

Monday, March 10, 2008

Wanted photos of Mirror Dinghy Rigging

Unless I am mistaken there is no resource out on t'internet that shows a complete photo montage of how to tune up your mirror dinghy. There are some good tips on the UK Mirror Sailing www site that primarily seem to be aimed at those starting out. The various sail makers also have data sheets recommending how you set up the rig for their sails. Obvious examples of these are Speed Sails and P&B Bermudan and Gaff Rigs Part 1 and Part 2.

What is missing is some of the implementation detail that takes you to the next stages beyond a beginner. For example - Where exactly is the best place to fix that fitting and where is it best lead to - without moving it around every week creating new holes in the deck.

Over the last couple of years the rules have changed quite dramatically - Bermudan rigs, centre mains, to the new Winder hull.

I guess if you are out on the circuit every couple of weeks its easy to take a quick sneak at a competitors' rig. However, for those of us that have not yet made it out onto the circuit rig fettling is near on impossible.

So thats my aim here to bridge that gap from the club sailor thats grasped the basics and wants to improve their rig set up (and spend some money!). Essentially, I am looking to record various versions of the sail controls - Kicker, Outhaul, Downhaul, Jib tack, Spin pole set up both from he traditional Gaff rig and the new Bermudan rig. What gets lead back to where etc. Anything that you think has helped you set up and control your Mirror be it major or minor lets record it.

The description of the fly away pole set up on the UK Mirror sailing www site is excellent but fails to discuss how the pole downhaul is set up. Lurking on the mirror forums last year I saw the painful exchange of messages trying to describe how and where the pulleys, rope and elastic were deployed. A couple of photos would have solved the problem instantly.

Interestingly both the UK Mirror Sailing and the Mirror Zone www sites both have a placeholder for (further) technical guides. This situation hasn't changed in the last 11 months I been a mirror owner. OK, so this is probably at least the third attempt to kick something like this off. I will give it a couple of months and evaluate progress. The best things in life tend to come from shared experiences. I'm just a conduit that can make that happen - so I need your rig set ups.

To some extent capturing this information via a blog is not an ideal long term home for such an important information base. It does have a couple of advantages though - its Free and easy to set up and maintain the resources. An obvious problem I foresee will be cataloging the various tips to allow readers to quickly navigate to them. However, at the moment I see resolving the navigation to loads of tips as one of those nice problems to resolve.

So get clicking with the digital camera and send me pictures from your rigged Mirror dinghy. An accompanying description on why it works for you or suggested improvements would be excellent. Don't worry too much about the sizing of the photos I can sort that out at publication time. Just try and ensure that they are in focus!

My email address is

NOTE: Photo wise I am looking for just pictures of the boat and rigging. I do not want images of people proudly showing off their Mirrors!