Clipper's Vera Cruise Build

Clipper's Vera Cruise Build

Tuesday, December 10, 2013

Positioning The Last Frame

As winter comes upon us (earlier this year - and colder!!!) the focus of building has to shift away from construction and into research and other indoor work. Already mentioned in previous posts has been the work I am attempting to do on the electrical system design. I won't go into that right now since it is just a bunch of reading and trial and error drawings as I learn.

The drawing I posted a few articles back looks childish to me now, but I am not so naive as to think I have reached a point of full understanding. No, I will continue to draw, research, and re-draw the design, picking up a little more knowledge here and there.

I'm hoping that by next winter I can have some form of heating in the garage so that I can get some outdoor work done . This year has been all about conserving money and applying it only to purchases directly related to the boat or items that I absolutely must have. So,no heaters in the budget.

But some work has been done since the last posting and I will show what I have done.

The first bit of construction occurred a few weeks ago during a brief warming spell. This allowed me to get some epoxy work done and glue the breasthook to the stem. The breasthook is a triangular piece that mounts to the top end of the stem and allows the two top side pieces (the sheers) to connect to the bow of the boat.

 I want to glue the stem into position on frame 5 next but before I can do that, I need to determine the exact location of frame 6 on the stem and provide a positive way to insure I get it to that position when ready to install. Frame 6 will be installed after the stem is permanently attached to the boat structure. Being cautious, I am trying to insure that I have any issues worked out before gluing the stem to the boat.

Here are two pictures of frame 6 being positioned. Readers will remember this is the smaller triangular frame with the wood inlays.

Frame 6 does not have any positive locators on the building form and only a single positive locator on the stem. This is the step on the stem shown in the second of the first two photos posted. Frame 6 must be located a specific distance fore and aft and at a specific height on the stem. Both dimensions are important so that other parts will eventually connect between frames 5 and 6 and the breasthook correctly.

Establishing the fore and aft dimension is fairly straightforward (although more on this in a moment). Setting the vertical position took a bit of head scratching. What I ended up doing was using a water level to establish the height of the building form. I then propped up the frame with small pieces of wood to hold it in position vertically. You can just make out the small wood scraps under frame 6.

The water level is simply a plastic tube filled with water. One end of the tube is set at the height you want to duplicate (the building form height). The other end of the tube will automatically show that height wherever the tube is placed. The next two photos show this.

This picture is the end that was used to set the building form height at frame 5. Not really visible in the photo is the water in the tube which is right at the line of the building form where the frame is resting.

The other end of the tube is taped to frame 6. You can see the water level in this picture. The plan dimension from that point down to the bottom of the floor timber (triangular piece in the photo) is 13 inches . By adding various thicknesses of scrap wood under frame 6, I got it to a point where the actual distance matched the 13 inches from the plans. I wrapped the small scraps of wood in tape and saved them for when I eventually re-install frame 6.

Fore and aft distance is another story that is still in flux. Because the bow is tapered, the frames need to be in proper position in relation to one another so that when the sheer is sprung around the corners, there will be no gaps. The following photos has a couple of red lines added to try and illustrate this. You can imagine that if the fore and aft distance is off, then frame 6 will either extend out too far or not far enough.

Unfortunately, I have found some discrepancies between the dimensions on the plan and the actual placement of frame 6. I have been trying to figure this out and have ruled out that the stem is mounted incorrectly or too short. The height of the breasthook above the floor is also correct. The only discrepancy I found in the plans is a slight difference indicated when measuring the plans directly. They seem to indicate a shorter distance than the actual written dimension.

Since I am currently at a loss to explain what is going on, I am going to spring temporary battens around these points and see where the frame actually sits. As long as everything lines up, I am not worried if the dimensions on the plan are different from the actual measurements. If they don't line up, I have a bit of fore and aft free play that I can work with. We'll see and I will let the readers know about that situation in the next posting.

So that's it for now. The weather is supposed to get a bit warmer this weekend and perhaps I can get the stem glued in place. Of course that depends upon what I find out about the position of frame 6. 

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