For the very latest activity, click here: From a Bare Hull

Saturday, April 30, 2011

Battery Cable Wrap-Up

I chose a house bank electrical configuration and wrapped up the battery connections. This involved fabricating solid copper buss bars and small jumpers made from 2/0 battery cable. I also did the final routing of the house bank battery cables to the main battery box. This involved securing the cables to the bulkheads with the Weld-Mount System, my first experience with it. Very cool stuff, indeed. I will let the pictures speak...
Cable ends routed into the battery box.
Cables mounted behind fresh water PVC with Weld-Mount system.
Fuse and terminal panel with buss bars, jumpers and protective covers installed.
Next step from here... battery switches and distribution terminal strips.

Tuesday, April 26, 2011

Electronics Cabinet Carcase

Last weekend, I cut, glued and screwed together the cabinet carcase for what is intended to be "electronics central" for the boat. This cabinet will house the main units for devices that have remote control heads. The main cpus of devices such as computers, radios, etc will be in this cabinet.
Freshly assembled. Next, some sanding and paint.
Shown in the picture are black mounting rails ($20 on eBay) that accept a standard 19 inch wide rack mount devices. This is the same size you typically see in large computer IT installations with racks of computer equipment. Or in recording studios with racks of effect processors, etc. You can get (or make) pretty much anything in this standard size including computers, shelves, general enclosures, etc. The hope is that this will help in the organization and modification of the electronics systems over time. I am hoping to avoid "rats nests" of wires as things are added and removed.
The current rats nest aboard the small boat. Just what I am hoping to avoid.
The cabinet will fit in the side space underneath the dinette table, left of the footwell, against the hull.
Dry fitted in place.
Other features planned for this cabinet
  • Integral DC power sub-panel
  • Mounted on removable over-extending drawer slides. This will allow the entire unit to slide out to allow side and rear access to connections. Or, with the disconnection of the electronics head units, the cabinet can be removed entirely from the boat.
  • Integral cooling fans to keep the devices cool.
  • Key locked to prevent theft.


Sunday, April 17, 2011

Battery Cables... I Don't Like 'Em.

No sir. I don't like 'em.

Making battery cables is one of those tasks where the enjoyment of building a boat wears pretty thin after doing it once or twice. It's just tedious and boring. Dealing with stiff 2/0 size cable is annoying. But it has to be done. Making a battery cable generally goes like
  • cut cable to length (with cable cutters DESIGNED for large cable. No, your typical wire cutter/pliers ain't gonna work.)
  • on the ends, trim the plastic jacket back about an inch (with a utility knife, careful you don't cut yourself)
  • slip the properly sized lug on the end and crimp (with a crimper DESIGNED for crimping large size lugs. No, squashing it with pilers/channel-locks/vise/whatever ain't gonna work.)
  • seal the base of the lugs with a generous piece of heat shrink.
If I wasn't obvious, this is a task where you need the right tools for the job, otherwise you are guaranteed failure. 

Our supplier recently had their annual sale for their regular accounts and we were able to get two 50 foot spools of 2/0 cable around 15% lower than our already low price. With price of copper going up, we took advantage. Anyway, the temporary 'non-marine' battery cables have been removed and the permanent ones installed. 

Cables for starter and electronics battery
Cables for both house banks exiting the conduit. Yet to find their way to the battery box.

Friday, April 15, 2011

DC Electrical Mains

After finally receiving a couple back ordered parts, I finished assembling the (admittedly overengineered) panel for the main DC terminals and fuses. Always trying to optimize space while keeping things tidy, it *just* fits between two pairs of fuel supply/return hoses for the day tanks.
Panels mounted between fuel hose runs
Mounted in the right hand panel are the pairs of terminal studs for each battery bank. The studs feed through the bulkhead and have a nut/washer on the other side (they are designed for thru bulkhead  applications). The battery cable lugs will be attached on the other side. The battery boxes for the electronics and engine start battery are directly behind the terminals, inside the aft dinette riser. Behind the House Bank terminals is the large PVC conduit that feeds the battery cables for the house banks, located under the floor, center, forward end of the main salon.

Mounted in the left hand panel are the main fuses, shunts and "first stage" distribution terminals. The fuses handle 125 amps. The shunts are used to measure current flow for the battery monitors (coming later),

As you can see, not everything is connected. I have a little flexibility here as to how I can wire things, of which I am undecided. By fashioning jumpers (made of flat copper bar, or short sections of battery cable), I can patch things a couple different ways. I could use all four fuses for the + lead for each of the four battery banks. Or I could fuse each of the + and - leads for each bank with the addition of a few more fuses in the space below. That probably sounds a bit overkill as you do not usually see both sides of a battery bank fused.

Why fuse the '-' lead?
It comes from amateur radio where it is "common practice" to fuse both leads. The reason: lightning does not discriminate the '+' from the '-' wire, it can just as easily strike the non-fused side and fry your battery and/or equipment. In a SSB installation on a fiberglass sailboat, it is common to tie all large metal items together with the ground system in order to get the best radio performance. This includes: life lines, standing rigging, masts, tanks, engine blocks, etc. which turns the boat into one big lightning rod. Anything you want protected from a lightning strike, like batteries, should be behind a (fast acting) fuse. Now lightning strikes are not common around here, but are more likely to happen in tropical areas. Protecting sailboats from lightning strikes, with their big lightning rod sticking up from the middle, is not an exact science. So, it is all down to how paranoid do I wanna be?

Like I said, I am undecided,  and I got time. Which ever way I choose, I could always change it later with little effort.

Tuesday, April 12, 2011

More Cabinet Carcases...

...in the galley. I added the large drawer assembly on the right, and the small under-stove one on the left. Just dry fitted for now.  Not quite a perfect assembly and paint job, but it will be covered up and the carcases should be square enough for the drawers. I did make a mistake cutting the small one on the left. The side supports don't extend far enough forward, I wont be able to put the face frame on it. I think I can fix it by trimming out the front, or I may just re-cut it entirely.

Stove space on the left, drawer underneath. Drawers on the right.
Closeup. All have removable access panel to get at the space against the hull.

Saturday, April 09, 2011

How Things Are Really Happening

Some time ago, after the floor supports and primary bulkheads had been glassed in, I speculated how the rest of the build might proceed. I think I said something like "Easy, I will start at each end and move to the middle". Well, as is often the case in this kind of project, things don't quite go the way you had planned. So far things are turning out to be just the opposite, and for good reasons. One being, I am still undecided on bow pulpit and steering mechanism design, and not that keen on making the capital outlay for those just yet (read: I don't have the money). It is ending up as building from the middle and moving outward. This has its advantages:

  • with electrical, plumbing, mechanical mostly centralized in the engine room and moving outward, it gives a lot of opportunity for organizing and running the "tentacles" outward to the rest of the boat as the local areas and systems are are built out
  • the cabinets in the main salon (dinette risers and galley cabinet carcases) provide a nice temporary storage space for tools, parts, etc,  that are already accumulating inside the boat, needed for the current "semi-finish" build phase. Helps keep me from tripping over bits and moving them from one place to another.
  • And, the extra height provided by the dinette riser puts my portable workbenches at a nice height that doesn't kill my back.

Wednesday, April 06, 2011

Engine Room Floor...

... is in, with hatches for storage underneath. This is the floor upon which one would sit while at the workbench in the engine room. Flavored with Bilgekote White and silica non-skid sprinkles, the hatch covers include stainless folding twist latches to positively lock them down (one wouldn't want stuff falling out when the boat is upside-down, right?) The hinges are mortised and the latches are recessed to keep toe-stubs to a minimum (though later I will probably put something like Dri-Dek over it). Now, its not perfect; the paint/primer is not that smooth and there was a mistake cutting one of the hatch covers. It ended up being a bit narrower than it was suppose to be. So the reveal on the sides is a bit wider than the top and bottom. Oh well. Its only the engine room. I can always recut/repaint the hatch cover if it keeps me up at night.
Joining, assembling, glueing and screwing.

Finished floor with hardware, paint, non-skid.

The smallest of the hatches.

Saturday, April 02, 2011

First Galley Cabinet Carcase: I'm Calling it Good

First galley cabinet carcase has been assembled, painted and fitted. Ready for four drawers (and a face frame). Includes lower storage access against the hull. The main salon layout allows for a maximum drawer travel of about twenty inches (before it hits the opposing sink cabinet). This leaves about a ten inch gap between the back of the carcase and the hull that could be used for storage. So, a deep "pocket" was built into carcase that will be accessed by a removable bottom in the cubby hole behind the counter backsplash. It is about 12 inches deep and is big enough to hold a large Costco size olive oil container.

1000 words follow...

Five large holes near the top are for ventilation.

Top view. Note the underneath storage at the very bottom (access cover removed).

Storage in "cubby" hole between hull and back of carcase.

Holes in the back to run conduit/hose/wire/whatever, if needed.

Update: As you can see, the carcase ain't perfect. In this particular project, I cut my teeth on the CNC machines accuracy and precision. Despite careful measurement of the plywood thickness, the dados cut by the machine ended up being a bit too narrow (by about 1/64th of an inch), enough to make assembly somewhat of a pain. I have since discovered the software setting that can compensate for this. Also, this project revealed that I need to do something about the machine's accuracy, precision and consistency before I use it to cut more detailed stuff like drawers. But for now it is ok for things like carcases.