Pages

Wednesday, December 21, 2011

Das Boat Update

Managed to find some time to work on the sub.  Actually, I had found that one of the blocks of wood developed a slight twist.  Most would say it was minor, but I didn't want it to escalate into a twisted master model.  I placed the two planks together, clamped them flat, and then dowelled them.  I then let it sit for a few weeks.  I just took the clamps off and presto, the twist was gone.


The next step was to make a template from the plans for the side view of the sub.  I chose the side view since the top and the bottom of the hull are relatively flat, that would save some time handworking later on. 


 In order to make sure all was square, I had to handwork the sides of the block.  Luckily, I had a bigass block plane I bought at a flea market during the summer.  With my block plane, and square, it took approximately an hour to get the side flat and square with the top and bottom.(+ or - .005") yeah that's right, I checked it from one end to the other with a feeler gauge.


 I found some template material sold by a vendor at a model show in Toledo a few years ago and bought a few sheets for just such an occasion.  The pieces were not long enough for the eight foot sub so I made it out of two pieces, with an overlap in the center.  This stuff is FANTASTIC to work with.  Score it and it snaps fairly easily.   While I was tracing the periphery from the plans onto the template material I decided to put as much detail on it I could, regarding contour lines. This would help line up later on.

When working with the plans some of the section lines in the side view didn't look constant.  I decided to measure the distances between each one (learned that trick working on automotive tail light plans) and sure enough some were 50mm, some 48.5, some 25mm and one section wasn't even labled,  Section 39.   I measured and documented the distances between the sections, then documented the distances so I could match it when I laid them out on the block.

A second anomoly I noticed was the number of sections labelled Section 25.  I understand why the designer did this, since they are all identical.  I labelled them 25A, 25B etc. 

Note the above photo.  The numbers at the very top of the block are the distances between the section lines.  The second set of numbers are the actual sections (Yes that is 10 1/2, and 9 1/2).

I lined up the template material to the section lines, and made sure the bottom of the hull would be lined up with the bottom of the block.  This would save me from cutting out the whole periphery.


The next adventure was to cut the blocks.  Since I only had a 14" bandsaw, with a throat depth of about 7 1/2"  I opted to cut the planks one at a time. 



Once the board was rough cut, I used a chisel, and my trusty square to make sure the whole periphery of the sub block was flat and square.  This takes a while to say the least. NOTE:  The conning tower will be added later.