Sunday, February 22, 2009

Crimp, crimp, crimp

That about sums it up. I continued working on the engine electrical system this weekend. After shoveling the driveway of course. That seems to be a regular weekend chore these days.

I installed a few more electrical bus bars. Top left is connected directly to the battery and alternator. Just below comes off the 'Ignition' switch. In the middle is the bus for the navigation lights (top is +, bottom is ground)and engine instrument lights (switched through the engine electrical panel. On the right is a connection point for the ground wire. The battery negative terminal is connected to the engine flywheel cover (as per original) which is in turn connected to the ground bus.

I went ahead and ordered #4 guage wire and connectors to run the full alternator output to the ammeter at the back end of the cockpit and back to the 'battery bus' at the engine. The rest of the system minus the switch panel is about complete. The alternator has a max 37 amp output but I am selecting wires and the guage in anticipation of upgrading to a 60 amp output alternator at some point. For general wiring I am using #12 guage. I could have gone smaller on a lot of it but #12 covers 90% of the boat needs and I just felt it easier to stock one size rather than rolls of many different sizes and colors. It means that sometimes a 2 amp draw is running through wires capable of handling 20 amps but I did it just to simplify my stocks of wire and connectors.

So, the battery bus feeds the switch panel, bilge pump(s) (not connected yet), a automotive type 12v utility socket (cigarette lighter) and provides a connection for the alternator (bus bars are rated at 100 amps)

From the the 'Ignition' switch, power goes to the 'Ignition' power bus bar. This feeds the ignition coil, electronic ignition sensor (replaces the old mechanical points) and after passing through the oil pressure safety switch, the electric fuel pump (temporarily removed)

From the 'Navigation' switch, power goes to the navigation bus bar which will power the red, green, white and engine instrument lights. I don't know if these will be connected by launch day. Its there for whenever I can get to it.

Whatever is not grounded directly through the engine, like nav lights, coil, and fuel pump, is connected to the 'Ground' bus bar

I have yet to run the power and sensor wires to the engine instrument panel. That has to happen out in the cockpit and it is cold out there. I also figured I would wait until I have the panel installed so I can run all the wires in a bundle at the same time. Darn, I just remembered I need to order more wire for those sensors...

I did run the common power, ground, and light power wires to the individual guages. Single wires from the just installed terminal blocks will supply guage power, light power, and a ground to complete the installation.

Doesn't look like much I know. I am waiting for the switch panel to be installed before I bundle up the wires neatly and secure them.

Replacing my stock of crimp connectors, shrink tube, and the #4 wire and connectors ran up my weekly bill to about $150. It looks like my total bill for the engine wiring project is going to run around $300-$400 just in wire and connectors. I have no idea where it all goes...

With the epoxy having set this week, I used a belt sander to clean up the instrument panel frame.

I really wish I had a table saw.
With a skilsaw, plane, and chisel I cut out the 'notch' (the proper term escapes me) that will allow the panel to insert into the hole in the cockpit well.

Here is a preview of what the panel is shaping up to look like. I think I can finally justify a router. I want to put a quarter round on the outer and inner edges. I have been wanting one for years and I think I am finally getting to the point where I am not going to be happy with the results unless I get one. Free handing the curved edges gets old and is tough to get perfectly. With my interior furniture projects getting closer I think its time and this would be a good job for it.

Sunday, February 15, 2009

Sparking some interest

I managed four or five hours on the boat this weekend and managed to get something done in regards to the engine electrical system.

But first, over the past month, this beautiful creature has been growing right next to me at the boatyard. Today, I saw it turning for the first time. Silent and beautiful and clean. I love it.

I continued glueing up the engine instrument panel frame. Doing the frame one joint at a time is introducing some uneven-ness that will have to be rectified later. I should have bought four clamps and done it all at once so I could control the layup better. I can fix it but I could have done better.

I started making up the wiring harness for the engine. First, I had to clean up the old wires. I really wished I had something to clean the engine with. It is looking dirty with lots of fiberglass and primer dust on it but the water at the boatyard is turned off for the winter so a good scrubbing will have to wait.

I forgot to bring anything to clean up the connections so I just left them loose for now. I thought I had more electrical terminal strips but a couple of them looked old and dirty so I ordered a few more. I installed the two decent ones that I had over the engine to get me started. The upper one is connected to the battery. The lower one is downstream of the 'ignition' switch. I will add a third one soon that the nav lights will connect to. Nearby, I will install a fourth for the ground connections.

I thought I had ordered an externally shunted ammeter but I guess I didn't. I have an internally shunted ammeter*. That means I have to run the full charging load through the meter which will be located at the aft end of the cockpit. For a run that long I need some larger wire that I didn't have on hand so I had to skip that bit. The battery connects to the hot terminal on the starter. A second wire off the starter hot terminal will run to the ammeter and back to the 'battery' terminal strip. On the other end of the terminal strip is the alternator connection. That puts the ammeter between the battery and alternator and the rest of the load where it belongs. The ammeter doesn't really measure total system draw, it measures the charging / discharging current to the engine start battery. When the house system goes in it will have a separate ammeter for keeping track of total power consumption.

Not too exciting. I ran the wires from the 'ignition' terminal block to the oil pressure safety switch / electric fuel pump. Also, on the same terminal, the power to the coil and electronic distributor.

When I get the rest of the terminal blocks installed I can run the rest of the wires and bundle them up in a nice neat harness. Pictures now would look boring and slightly hideous. After I finish writing this blog I am going to spend a bit more time with the electrical panel and get that ready to wire into the terminal blocks. There really isn't much to an A4 electrical system.

On a side note, I took my electrical temperature guage to the boat and was reading 71 degrees near the cabin roof and about 60 degrees down by my knees. The temperature outside was just below freezing so I think the cabin insulation is definately working.

That's it for now. I took some more pictures of the engine so I can update the 'engine' page on the website - dirty engine and all but I need something to do weeknights.

Roughly 15 weekends before launch. I am starting to feel the pressure.

*For those of you that want to know what shunting and ammeters have in common:

A typical ammeter is a sensitive electrical device requiring only a few milliamps to operate. Running the whole load through the a meter would require a huge and heavy device to handle the big electrical currents. The shunt is a bypass. Most of the current goes through the shunt and only a little goes through the meter. Now for the meter to operate properly, it needs to be calibrated to the shunt. The meter has to know that, say for example, 99% of the load is going through the shunt and 1% is going through the meter. That way the meter can read 100 times more than what is actually going through it so that it can accurately show the full system current. An internal shunted ammeter has terminal connections for the full load. The whole load is taken to the meter case. Inside of the case the shunting occurs. On an externally shunter ammeter (which is what I wanted but didn't get) the shunt is located somewhere convenient, say off of the starter terminal, and two tiny wires carry 1% of the system current back to the meter. That would have been better in my system with the meter 6 feet away from the rest of the system. Its okay. It will work. But I will need to buy 12 feet of 4 guage wire or something like it to carry that much current over that distance.

Sunday, February 1, 2009

Winter Slog

This week the boat has a three foot iced over snow berm all around it. I spent Saturday chipping ice out of the driveway after spending an hour trying to get the truck out of the driveway over the 3 inches of solid ice. Dog days of winter.

I started glueing up the engine instrument panel frame.

I want to re-mount my spicerack/secondary electrical panel on the aft end of the cabin but I don't want to see the screw heads on the outside. I spent way too much time fairing the cabin sides and prepping them for a smooth paint finish to have a couple of random screw heads poking through.

The solution was suggested to me by a friend of mine. Build a back panel for the spice rack, Glue it in and screw the rack to the back panel. There is quite a bit of surface area to the panel and not much weight on the rack so I think this will work. Clamping the panel to the cabin while the epoxy sets is going to be the tricky part. I will put flush counter sunk machine screws under the panel and protruding into the cabin. The spice rack will mount onto those screws. Today, I cut out that panel from some left over 1/4" okoume plywood. I think I will varnish the visible surface before I glue it in. Or maybe just paint it white. I don't know yet.

The rod end for the transmission shifter cable came in. Someone listed the dimensions incorrectly. I thought it was odd that an aviation supplier would have the right sized clevis end. In my 15 years of fixing airplanes I have never seen a fitting that large. The fitting I received is not nearly big enough. Here is a picture of the 1.)original, 2.)recently ordered fitting, and 3.) fitting that came with the cable.

To make matters that bit more frustrating. I looked at the rod end and ordered the clevis in a 5/16" fine thread. Turns out the thread is metric so it won't screw onto the cable. The original clevis I received was only listed in the catalog as 'clevis for series 60 cable'. Now I know series 60 threads aren't fractional. Learn something every day. That one only cost me $15.

I am thinking the solution is to file down the fitting that came with the cable just a bit so that it fits inside the original beefy bronze fitting. After jamming it in I can just fill the void with thickened epoxy and call it good. It will look odd but it should work okay.

Next week I have a maxed out social calender. I might have time to snoop in a buddy's boat shop and find something I need. Otherwise, the project will continue to creep along at this abysmally slow pace.

An old boss used to tell me that somedays, "all you can do is to push the ball forward. Try to make progress somewhere". Another friend has told me that the secret to being successful is to, "keep working, and it will get done." I am pushing the ball forward and working. That's about all I can say these days.