Building frames

December 2012; We were finally able to start building the jigs for the hulls.

The design that we bought from Schionning was so new that we had to wait while the first set of drawings were being scrutinised for CE approval.

Scale Mode

We made use of that time by going ahead with preparations for the build. We also took the opportunity to make a scale model of the jigs for the port and starboard hulls.

schaalmodel bouwspant   schaalmodel bouwspant

These models turned out to be very useful, giving us a good idea of what the final jigs will look like. After studying the models for a while we decided that some frames looked a little weak around the outside, and that others needed strengthening at the bottom. Based on our new insight, we decided to modify the frames by adding an extra 10cm around the outside edges and strengthen others where we felt it necessary. We were able to do all this with our available stock of forty MDF panels.

It became clear to us that Schionning had put a lot of thought into their design, and how to build it. Where possible, parts have been designed with straight edges. This allows us to make efficient use of our building materials.

Building frames

As you’ve may have already read by buildingmethod we decided earlier in the planning phase to work with a female jig instead of a male jig. A female jig will enable us to screw the slats directly into the frame profiles. The drawings made by Schionning are of male jig sections. Paul spent a few hours modifying the original frame sections in AutoCAD. He basically subtracted the height of the slats from the frame profiles, only a few centimetres in all, but it insured that we can build the remaining boat sections without having to modify them first.

tekeningen bouwspanten

We have to use three datum lines in order to accurately position the frames: the Waterline, the Centreline and the Deck-line. These were all clearly marked on each of the frames. There are eighteen frames per hull, many of which are made up of three pieces. We had to cut out eighty-six parts in all.

Paul designed a cutting plan that allowed us to cut all the pieces out of our MDF panels with as little waste as possible. We did consider having the pieces cut professionally using a computer controlled laser-cutter or router, but in the end decided to do it ourselves. This is where our A0-plotter came into its own.

On Friday 7 December all the materials necessary for the jigs had been delivered. Full of enthusiasm, we made a start.

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Using A0 size prints from our plotter, we were easily able to transpose drawings onto the MDF panels. It was tempting to trace around the cut-outs from the port hull and use these as a template for the starboard hull. It would appear to be a lot faster this way, but if you make a mistake, you’ll have two parts to re-do instead of one.
There are only a few small differences between the port and starboard jigs, but if you saw the frames in one go you know exactly what to look out for and the job goes quite quickly.

After three or four evenings Jolanda had managed to transpose all the frame drawings onto the MDF boards and Paul had already sawn a few out.

bouwspant tekenen   bouwspant zagen

When not jig-sawing, Paul spent time experimenting, trying to find the best way to assemble the frames, it was also a good opportunity to see if our plan was working.

Spending hours lugging large MDF cut-outs around, getting down on your knees to assemble them and then moving the completed, full size frames around is absolutely exhausting. It’s a nice thought knowing that this will not last for forever, and that in just a few days we will be able to start working with luxurious, light and easy to handle foam.

bouwspanten samenstellen

Whilst assembling the frames, we took the opportunity to strengthen the weak looking areas fit legs. We also fitted temporary battens to keep the frames in shape.

Aligning and rigging the building frames

Whenever we’re busy working away on our boat, tended to find ourselves drifting off and thinking ahead to the next steps. It is this curiosity that becomes the driving force in the build and keeps the pace up. Hopefully we’ll never lose this drive.

After completing a few frames it was clear that our plan was working well. We decided to finish the remaining frames together at a later date, but first we wanted to make a start on assembling the starboard jig.

Following the positioning of frame 1 comes the positioning of frames 2 to 18.

Starting with the stern as a reference, each frame had to be accurately positioned in all three planes, and relative to each other.
The final position of each frame was then marked on the floor. The whole process took a lot of time, the first few seemed to take forever, but it’s well worth taking your time and working accurately.

bouwspant 18  bouwspant 0  bouwspant uitlijnen_1

 

This is what we managed to achieve in the first month of building:

bouwspanten bakboord  bouwspanten bakboord zijaanzicht  bouwspanten stuurboord   bouwspanten 2 rompen

In January. . .
We’ll start fitting the slats; these will form the base for the foam layer. By the end of the month we hope to have a fully foam-clad hull.