Archive for the ‘CNC Boat Molds’ Category

Mold Installation

Saturday, January 9th, 2010

All of the molds have been installed. You can just see the stem mold on edge followed by the other molds. Each mold was aligned in the X and Y axis using a laser level. Setting up the laser level was more difficult that expected. To get laser to line up with the center line and with the 10 inch horizontal line took a lot of trial and error. The edges of the molds will be covered with plastic packaging tape to prevent the strips from getting glued to the molds.

The next step is the cut the strips and then route the bead and cove.

First Stem Mold

Monday, January 4th, 2010

I installed the braces for the station molds and the first stem mold. Each of the molds have been marked with a vertical center line and a horizontal line 10 inches up from the base. If everything goes correctly each of the molds will be in alignment in both the vertical and horizontal plane. This alignment does not need to be perfect but I don’t want to start accumulating too many errors this early in the process. The next station mold to be installed is Station 1 followed by station 2, 3, 4 … until I install the other stem. I will setup my laser level to help make sure that the stem mold and each of the station molds are in alignment.

Puddle Duck Molds

Thursday, December 24th, 2009

The molds for the Puddle Duck were cut on a ShopBot CNC Router out of 3/4 MDF. Shown are one half of the molds, the mold for station 4 and the stem. The puddle duck is symmetrical so the molds for stations 1 &7, 2 & 6, 3 & 5 and the stems are the same. The clamping strips have been attached to the molds, so with a little sanding to clean up the edges the molds are ready to go. Clear packing tape will be put on the edges of the molds to keep the strips for sticking to them.

Molds Away

Sunday, November 29th, 2009

I finished putting the molds into CAD. I used TurboCAD which is not quite as easy to use as AutoCAD. My AutoCAD license had expired and I was not going to spend $1995 to get another year. TurboCAD is less than $99 and was good enough. The molds will be cut by Knight ToolsWorks in Portland OR. Once cut I will glue the clamping strips to the molds and do any clean up that is necessary. I will also cut the holes for the clamps in the stem, I could have had the CNC machine cut them but I don’t know where I want them. I will decide when I glue up the inner stem. The next step is to build the strong back once I get the garage cleaned up.

Mold Design for Puddle Duck 14 Canoe

Friday, November 6th, 2009

The Puddle Duck 14 Canoe has 7 station and 2 stem molds. Stations molds 1 and 7, 2 and 6, 3 and 5 and the two stems are identical. Station 4 is the center station of the canoe and there is only one. The patterns for the molds are from “Building a Strip Canoe” by Gil Gilpatrick. The patterns in the book were drawn in 2:1 scale and are shown half-breath for the stations and full profile for the stems. Measurements were taken from the book to the closest 1/64th to locate points on each mold so that the shape can be reproduced.

To take the measurements, a zero point on the pattern was determined in the lower left corner. At each crossing of an interval line the location was recorded. Since the pattern in the book covers two pages, the binding obscures the Y 5″ interval line. Two Y interval lines at 4 1/2 inches and 5 1/2 inches were drawn to fill in the missing data.

The points were entered into OpenOffice.org Calc to verify that the point are generally in the correct locations. Next the data will be entered into CAD and the points will be splined to make a fair curve. Some of the points may need to be adjusted to improve the curve. Once the half-breaths have been checked, they will be mirrored around the Y axis to make the full pattern. The stem pattern does not need to be mirrored because it is already a full pattern.

As part of the CAD process a description of each mold and a large cross centered at X = 0, Y = 10 will be placed on the ink layer. The cross and a description of the mold will be drawn in ink by the CNC machine. The points and lines that make up the outline of the mold will be place on the routing layer. The molds and the stem will be cut out of 3/4 (18mm) MDF by a CNC machine.