Thursday, September 25, 2014

Mainsheet Beam Cores Finished

 I spent several hours working to shape the laminated fir blanks.  The first order of business was to create an MDF template of the shape off of the drawings.   This required lofting a few points onto the MDF.  I then pulled a batten in line with the points against small nails. Next I hot glued the batten with support blocks to the MDF.  I could remove the nails and trim away excess material from the MDF sheet.  I then took the batten and MDF to the router table where I used a flush trim bit to cut fair curves.  This seemed more accurate than trying to sand fair curves to a line, especially on the concave side.

The batten flexed across nails.

Once the template was finished, I attached it to a laminated blank.  Using a saw and a belt sander (I still don't have a jigsaw), I removed excess material.  I then trimmed the blank to match the template using a 2 inch flush trim bit.  Almost all the excess has to be gone before using the large flush trim bit given the large load on the router when trimming over an inch and a half height (40mm) at once.

The finished template attached to the blank.

The blank cut and sanded close to the template.

With the blanks the correct shape, I moved on to rounding over the edges.  This is for aesthetics as well as getting carbon fiber to bond over the edges.  I also cut "nubbin" slots at each end.  These will keep the lashings that hold the blocks to the beams from slipping.

Finished cores after trimming, rounding over the edges and adding nubbins.

These are now ready for the first layers of carbon uni.

Task time: 6 hours
Total project time: 294 hours

Tuesday, September 9, 2014

Mainsheet Beam Progress

Both of the mainsheet beam laminations are done.

Here are the beams after coming off the mold.

Here they are after sanding and planing them flat to a 40mm thickness.

Next step is modifying the upper (concave) curve and shaping them.

Task time: 3 hours
Total project time: 288 hours

Pultrusion Dispenser

I have done five pultrusion layups on the aka beams since returning.  Having run out of cut pultrusion, I had to open a new 500 foot roll.  In order to avoid the "pultrusion hairball" that I discussed in a previous post, I quickly hacked together a dispenser.  It would work better if the inner dowels actually turned, but it gets the job done.

Task time: 25 hours
Total project time: 285 hours

Tuesday, September 2, 2014

CPlate Bits

I got these carbon plate parts from Turn Point Design today.  Brandon laid up some 6 mm cplate out of carbon scraps from bigger jobs and then CNCed the parts. These are just a few of the assortment. The washers are for reinforcing the aka bolts.  The long triangular ones are the forestay attachments to the bulkheads.

Monday, September 1, 2014

First Mainsheet Beam Layup

I ripped some Doug Fir for the mainsheet beams.

I went with wider 7mm boards to try and reduce spring back after unclamping.  The thicker laminates put up a fight when tightening them down.

The layup is molded to the lower more gentle curve.  The top asymmetric curves will need to be cut with a bandsaw later.

The beams run athwart the main hull as shown in the picture.  There will be a block lashed to each end.

Task time: 7 hours
Total project time: 260 hours

Milling Stringers

We spent a couple days ripping and planing stringers out of CVG Doug Fir and Sitka Spruce.

The stringers were ripped a few millimeters oversize.  I used a new Freud Thin Kerf Glue Line blade that did a really nice job.

The main hull needs 60 meters of 19 x 25 stock for three courses per side,  The ama requires 38 x 25 stringers and a 25 x 25 deck beam.  The ama is expected to take some pounding, so the timber is a bit beefier.

I was able to rent the use of the large Powermatic planer at the Northwest Maritime Center.  The planer allowed me to remove any saw blade lines as well at get the thicknesses down the the millimeter.  All of the stringers were run through together to ensure identical thickness.  Nice scarfs are dependent on consistent thicknesses. The stringers also have to fit CNCed notches in bulkheads and come out flush with the hull sides.

Task time: 15 hours
Total project time: 253 hours