HMS Winchelsea 1764 by John Murray - 1:48

[John Murray]

Hi Everyone. I bought the plans and downloaded them several weeks ago. I was contemplating having Chuck send the starter kit to me in Australia. It seemed the easier way. However, I have chanced up a community makers space a few miles away which provides access to laser cutters, and woodworking machinery that I don't have.

 

I bought a block of Cherry a while ago and thought I would see if they could assist with sizing it into 3 x sections by ripping the 1 1/4" slab on a bandsaw. The bandsaw was waiting a new blade so they used a table saw. I sized the slices to 1/4" on their thicknesser.

 

I then used 2 of the pdfs I had for the stem to test out their laser cutter. It has a bed size of 1300mm x 900mm.  My little piece was accommodated with ease. 

One question I have though regards the bulkheads and keel pieces. They are 1/4" ply. That size is problematic in Australia being a metric country. I can source 6mm or with some difficulty 6.5mm plywood. Both are fine? grades for exposed faces in furniture production. 1/4" though is 6.35mm. If I substitute the 6mm OR 6.5mm ply, what issues could be expected further down the build? Thoughts or workarounds?

 

Edited May 25 by John Murray

[Chuck]

6mm is fine.  In fact I believe my bulkhead sets are 6mm

[glbarlow]

An ambitious beginning, looking forward to your progress. 

[John Murray]

I spent some time gluing up the parts. 

One thing I noticed whilst I was watching the laser cut was that around 2 thirds of the lines would cut with a single pass of the laser. These resulted in nice clean cuts. However, the remaining lines each had up to 10 or more passes which resulted in scorching and small holes from I assume reflections of the aluminium grid it was resting on as the beam repeatedly passed over the same path. 

As can be seen in the two images, some of the joints are spot on. However, there were other joints where the wood had been scorched away from repeated passes of the laser. This resulted in gaps in some of the joints. I have highlighted problem areas in the two images. The scorch mark are obvious in the images I posted above. That is the top side view of the board. The underside was much worse. I suspect the person operating the laser (I wasn't inducted) did not know how to correctly setup for the cherry. I did not notice a setting in the software for wood except MDF or Plywood.

I shall be modifying my approach to this piece. I used 1 1/4" cherry and after cleaning the scorch marks and correcting a very slight bow I induced from the glueup, To glue up I will be using pins and a board to hold the pieces flat whilst drying. This attempt though I did not. (I used my Proxxon Planer then Thicknesser to flatten and clean up both sides.) I ended up with a flat stem at 210 thou instead of 250 thou. 

It shall be remade and I am considering changing from Cherry to another wood that I can source in Australia. Poplar or Huon Pine. 

I have also attached an image of two other laser cuts I made on the same wood panel. This show the underside though with the scorching. Unfortunately I did not get an image of the stem panel underside.
 

Edited Wednesday at 07:07 AM by John Murray
Added an image.