Kayak Strongback Option 2

Just seen in a recent mailer from Bunnings - 4m aluminium planks for around the $NZ150 mark. Surely this would provide a good rigid base for building a kayak.

What Are The Odds?

You go walking along the Wellington waterfront and... end up on the 6 o'clock news on TV.

Apparently not so low. Check the last interviewee on http://tvnz.co.nz/view/video_popup_windows_skin/1842042 . Ah yes, that's me. Now I must admit this is at least my second performance on the biggish screen. I remember my primary school class being used as in the opening to Nice One Stu - a popular 1970s, kids after school TV programme in NZ.

Fortunately I suspect the video clip will be archived fairly soon. But it's good to know that in little 'ol NZ it's not that hard to end up in the media:)

Kayak Strongback Spacing Planner

Now getting away from banking, and remembering that I’ve kept my blog as a personal blog first and foremost, here’s an article (hopefully the first of many) on the building of (hopefully) 3 kayaks.

For some time now I’ve been prepping myself for the construction of a fibreglass composite kayak and finally I feel I’m underway! The basic process is to construct a sandwich core with a wood (or other) substrate used to create the form for the kayak with fibreglass on each side providing tensile strength on the inside and abrasion resistance on the outside.

There are two common methods for creating the sandwich core: stitch and glue plywood; and wood strip. I’m starting off with stitch and glue plywood but I have it firmly in mind to go on and create 2 more strip form kayaks. Wife and daughter will surely be bemused as I gift them their own high performance kayak...

The initial kayak is a Night Heron from Nick Schade at Guillemot kayaks. Check the web site and especially the message board he administers. This is an invaluable resource. Once that is done I’ve got my eye on Ross Leidy’s Whiptail, and one of Bjorn Thomasson’s kayaks in particular the Njord, Hunter or maybe Isfjord. No special reason apart from the fact that they just all look so HOT!

So, what about the strongback spacing planner you ask!? Well, when you build your sandwich core form you need a rigid straight guide. This is the strongback and you can create it in a variety of ways. (And no, I don’t need one for the stitch and glue Night Heron but it should make a good flat surface for construction and will suit my needs for the later kayaks.)

The thing is how you go about creating a strongback. I’m very keen on the approach taken by Bjorn Thomasson and Dan Caouette but in building one for myself I used (like Dan) doubled up plywood sheet strips (although in my case I went 150mm wide). The problem is when I went to bend them they seemed in a lot of stress and I wasn’t sure how to even that curvature stress out over the full length. Well, this is where a bit of geometry came in useful and I thought it was worth reporting out for others.

First a diagram; let’s use H to represent the length from the centre to the long end of the strongback, W the distance from the centre to the edge at the widest point (ie half the width), r to represent the radius of the circles that would make up the two sides of the strongback, and h and w to represent the distance up and across at an arbitrary point on the strongback.

How do you get the radius of the circles? Easy thanks to Pythagoras.

So, solve for r to get:

Question is now how to get the width at some arbitrary distance along the centreline of the strongback. No worries,

This time we want to solve for w.

And remember that the width at distance h from the centre is 2w.

Using Excel for my case where I wanted the total length to be 5.00m with greatest width 0.6m I get a table such as this.

Overall Length	Greatest Width	Circle Radius	Offset from Centre	Width
5.00	0.60	10.57	0.00	0.60
			0.50	0.58
			1.00	0.51
			1.50	0.39
			2.00	0.22
			2.50	0.00

Applying this to my sample kayak strongback gives me the following drawing.

Update: 9th June 2008: Thanks to the wizardry of Google Docs you can view a spreadsheet:

http://spreadsheets.google.com/pub?key=pYTbzqIDg8t4ncGmXY2EBIw

Or just view the graph here:

Future of Banking Conference

Or more accurately titled the 2nd Annual Technology and Innovation Conference - The Future of Banking and Financial Services.

Crikey, bit of a mouthful.

I attended this yesterday and spoke briefly just before lunch. Briefer than intended unfortunately because of the length of the previous presentation. Still, I finished on time and had a ball!

Main messages and comments:

• The role of IT, knowing why you're there: operations plus business transformation. Understanding just why you're so critically a part of the business whenever change is necessary, especially disruptive change.
  
• The need to sell and market internally. No innovation will get anywhere when you're not selling it. Just as a quick aside, I noted this come up a day ago in a post from James Gardner on BankerVision. It is hard but you *can* innovate in banks; just understand that the selling will be a great part of the effort.
  
• Handling of conflicts of interest especially product management versus project management. We do this so poorly in banks - the approaches taken for managing the ongoing development of software products that have enormous impact on the customer service offered by the institution is really quite simplistic. Considering that these systems are extensive pieces of IP consisting of code, hardware, ideas in the heads of testers, developers, analysts, architects, and managers, well we really should approach it like a software product vendor. We need to keep the people together and we need to balance off the conflict to build right versus build the right product. It was comforting to hear Jeff Smith from Suncorp also spoke about this within the first session of the day. In fact, quick note hear to say I was very impressed with Jeff's talk. Suncorp have scored well there.
  
• Finally I managed ever (ever) so briefly to talk about complexity and how to deal to it with services. Never had anywhere near enough time to talk about this one. I noticed that the IBM stand in the vendor area had a bunch of dice. I was tempted to grab a dozen, toss them on the floor and ask the audience how complex they thought that system was. Then split them into two groups of dice, put one lot on a desk and another on a different desk with a string between them representing an interface. Then I could show the transitioning of total complexity from multiplicative to additive. This would have given a good demonstration of the power of componentisation. As an aside I have done this before with a group building many sided solid objects from paper cutouts (tetrahedrons, cubes, dodecahedrons etc), I think it worked so there's a potential way of demonstrating complexity in a tactile manner.

A few general comments about the rest of the event...

Gosh what a lot of suits! and what a lot of people from ANZ! I guess their building was just right next door. Lot's of conversation about mobile technologies. Much overrated based on my experiences although I am very interested in the browser interfaces possible with the iPhone and Windows Touch phones. I can see that xhtml compliance with an understanding of modern phone browser capabilities could provide a far faster and more usable method of deploying mobile applications. Java midlets might let you control the buttons, but who cares when there are no buttons! Of all the presentations that I saw I found the most value in Jeff Smiths. Good commentary on people and approach with a good criticism of the prevalence of the waterfall approach to project managing complex system change in financial services companies. A real need for more maturity of project management in our sector.

So all in all a great time and now I'm looking forward to getting stuck into some real work back in the office.