Selasa, 01 Maret 2016

Lots of lofting


The despised kneepads are gone. The lovely new, gel-filled, velcro-on kneepads are staying. I had help with the lofting: Dad popped down for the day. He wore the old ones for five minutes and threw in the towel. I threw them in the bin.
With his help and a looming deadline Im making very good progress. The body plan went in very quickly, the half-breadths went down fair and the only points we could find that didnt look right were my plotting mistakes, not from the table of offsets. This photograph makes me very happy: a fair diagonal with no need to adjust any points.

This means that all the lines in the body plan will work.
Ive adjusted the colours in the photo to emphasise the red. Often builders will set out the diagonals in a different area of the lofting board from the half-breadths to avoid confusion. A different colour also sets them apart.
Its a testament to Paul Gartsides design and drafting that this all worked so well. Ive read detailed explanations about how to adjust points in each of the different views of the lines constantly chasing ones tail around the lofting board until all lines are fair. We didnt have to do any of that. The lines as drawn in the body plan are fair in the profile view, the half-breadths and the diagonals. Time will tell if the boat looks right.
I spent a devil of a lot of time on my hands and knees peering at increasingly faint pencil lines. I wont miss this and am looking forward to working upright for a while.
The last job left before I take up the boards is to develop the stem sections. The inner and outer faces of the transom are developed and looking good, the sections for the keel are drawn and I have finished the bevel board which means I could actually lay down the keel!
In the photo to the right you can see the keel sections. Kopanycia recommends drawing these on the body plan but says that because of the number of lines on top each other it will become "confused". My solution was to lay tracing paper over the body plan and then draw them in. Its not the drawings I want, so much as the measurements, so I can happily bin them but some how I cant bring myself to so inevitably theyll kick around the study until long after the boat is built.

A couple of things have vexed me.
Yesterday I set out to draw in the crown of the transom and discovered that my trammel beam was an inch short. At least thats how it appeared. I brought a piece a couple of feet longer from home but it was still too short! I taped the two beams together and that extra inch actually needed about three feet. In fact the end of the trammel had to be off the board to get the proper sweep from the crown to the edge of the transom.
What is the poor book Ive chosen to impale with trammel point? It was the first thing that came to hand at the right height. Stabbing compass holes in classical texts takes me back to my own childhood. I like to think Odysseus would be happy that its been scarred in an effort to bring a boat to life. Im not sure the Gartside #127 would have got him back to Ithica but it might have helped him escape from Calypso.












Im following Kopanycias instructions closely but sometimes he leaves me wondering. When drawing out the keel sections Ive been recording the measurements specified in the bevel board. Most of these measurements are taken from the outside of the keel, the bottom of the hog or apron or the top of the keel. However measurement A, which tells me where the ghostline/apex line/call-it-what-you-will is measured from the centreline, not the outside of the keel. This seems daft to me. Why not measure it from the outside of the keel which is surely going to be the surface Ill want to register my marking gauge or square from?
Its a small point but seems to ignore the purpose of lofting: to build a boat.

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