Well, here it is. This is the geometry data from the mock up testing finished last weekend. I will let the picture speak for itself. Turns out things could be simplified from the initial drawings I put together. Only the aft roller need be adjusted. I guess this why one does experiments and mock ups.
The aft roller positions will stow all four types of these anchors and will self-launch when released.
Also, the Windline rollers used in the mock up will pull through a 3/8" chain, with a standard galvanized shackle attaching to the anchor shank, without difficulty.
Next is to use this data to continue the pulpit design.
For the very latest activity, click here: From a Bare Hull
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Sunday, October 18, 2009
|From Building A Westsail 42: Latest Activity|
The apparatus is simply an existing work table with two pieces of plywood simulating the cheek plate, approximately the size expected and then some (so I could cut them down and really dial it in). Two rollers are mounted between the cheek plates using two pieces of all-thread as an axle, through holes strategically drilled through the plates. Also included is a 15 foot section of 3/8" chain and a standard shackle to test deploy and retrieval of the anchors to help simulate a real world setup.
I started with the bow roller placement from the initial CAD drawings done a couple weeks ago. This initial setup worked pretty well for all anchors I had on hand (Bruce, CQR, Delta). But the Bruce and CQR had trouble self-launching. Moving the aft roller up about an inch fixed this. Finally, I jacked up the front of the table to an incline I expect the pulpit to be at in order to match the sheer of the boat. It is about a 6 degree incline. Again the Bruce and CQR had trouble self launching, so, the aft roller goes up another inch to fix this.
In the end there are a series of holes in the cheek plates with pairs matching the optimal position for each style anchor.
Testing is not done however. I will be exchanging the 44lb Bruce for the 66lb this week to see if there is any significant difference for roller placement.
As for the "rollbar" style anchors like the Rocna, the problem is the rollbar hitting the underside of the pulpit as it is pulled in. The easiest solution is to drop the forward roller a couple inches. However, we cannot build that extra drop length into the cheek plates as it will screw up the optimal setup for the other anchors (like the Delta and CQR). Specifically, the cheek plates will hit the flutes of the anchor and block it from being retrieved into the fully stowed position. So, I am considering a couple removable "tangs" that will attach to the cheek plates and drop the forward roller. If we use a Rocna style anchor, we add these tangs and drop the forward roller. If we go back to another style, we remove the tangs and move the roller back up. That is the idea at least. Clear as mud? I will probably have a CAD drawing here shortly to clarify things.
|From Building A Westsail 42: Latest Activity|
Thursday, October 15, 2009
One of the things holding up the final design of the bow pulpit is the design of the anchor slots and rollers. We want an optimal design for easy launch and retrieval of anchors, and adequately accommodates different styles of anchors. The key will be the design of the cheek plates and placement of the rollers. What better way to design this than using full scale items? We purchased a couple different size rollers and two anchors of the style we will likely use first: a 44lb Bruce and 44lb Delta. I will be cutting and drilling some sample cheek plates from plywood to test various anchor roller positions. Shackled with a small section of chain, we will be searching for the best launch, retrieval and stowage setup. We have some concerns (and some readers have pointed out as well) that the 44lb Bruce might be too small for the W42, so we might exchange it for the next size up (66lb). A little "tweak" and we can convert the Delta anchor to a "simulated" Rocna anchor. More later.
Wednesday, October 14, 2009
Bill Crealock, designer of the popular Westsail boats (including this, the Westsail 42) as well as the famous Pacific Seacraft designs, passed away late last September at the age of 89. His obituary in the LA Times
"When computers began to be used in design work, Crealock said he preferred working by hand, mixing art and engineering in his designs. Crealock's designs were used for every craft from dinghies and brigantine-rigged sailing ships to catamarans and 70-foot powerboats. He even made some preliminary designs for a charter submarine."
With interior finish work looming over the horizon (beginning after the first of the year most likely), narrowing down the interior design is taking some priority. Our discussions could be summarized down to "not too traditional with a bit of modern". "Not traditional" meaning not a lot of intricate dark woods in small bits all over the place. We would like to keep some traditional wood tones but otherwise smooth and "less busy" surfaces. The attached image gives an idea of the style under current consideration. It is the port side of the forward salon. Ignore the colors and lighting.
Wednesday, October 07, 2009
A reader pointed out the lack of pictures on the blog of the overall project. Indeed, there were more pictures posted before I did the last blog cleanup. So, I added back a link to the web albums. See the sidebar under project details. These pictures are not very recent. I will try and get some newer ones up in the coming weeks. Link to Web Gallery Enjoy.