With Wings As Eagles: Craig P. Steffen's Blog

On the other hand

2008 January 31 00:40

I asked for and got a Matias half-keyboard for Christmas. I can type decently on it, but since half the keys require using the shift, and they're randomly distributed (more or less) interms of frequency, I've thought that re-mapping the keys might speed the process up.

Well...it turns out that someone's already done that. It's called a Frog Pad. It's a square keyboard that optimizes for the frequency of symbols. That should inherently make it faster to type on, but since it bears no relationship to the qwerty keyboard, it will be harder to learn.


learn something new every day

2008 January 28 23:00

I'm going to have to take the engine out of my beetle one day, probably this winter or early spring. I have a valve continuing to stretch on the right side, possbly due to an induction problem.

Getting the engine unmounted doesn't seem to present to much difficulty. However, getting the car high enough to get the engine out from under it has worried me, until now. I did a search this evening for "remove beetle engine" just to see what was out there, and I found this page on geocities. It suggests jacking the right rear of the car up, taking the wheel off, and then sliding the engine sideways so the top of the engine goes through the space left by the wheel, which seems like a very sensible thing to do. So I expect I'll try this.


it's a hundred and six miles to Chicago

2008 January 26 01:36

May I just say that I f***ing hate Chicago? One would think that a construction project that totally messed up one of the main interchanges in your interstate system might merit a sign, say something like "The I-65/I-80 interchange is under construction. Please take alternate routes". That would keep it from being a complete logjam of all the people from out of town who don't know any better and take it, thus creating a zone of slowed traffic that made it take 1 1/2 hours to get 3 miles. Did I mention it was snowing during this time? May the fleas of a thousand camels nest in Richard Daley's underpants.

HOWEVER, the reason that I ended up driving through the festering construction-zone hell that is Chicago is that I'm attending the Sportair workshop on sheet metal, as pertains to aircraft construction, this weekend. Should be lots of fun, then back to the real world next week. That's right, I'm in Oshkosh...oh yes:




the part of the electron will be played by...

2008 January 23 00:35

[WARNING: Technical content, which is then followed by pretty pictures]

I'm a gadget freak, and I tend to gravitate towards the gadgets that take up electricity. I can instantly think of dozens of electrical devices that I'd like to put in my beetle: radios, navigation gadgets, instruments, defrost blowers, lights, you name it. All of those things require power to work, and the 30 amp generator that came with the car in 1972 just isn't going to support too much extra load.

The solution is to install an alternator. They produce more electrical power, at lower engine RPM even. In the process of reading about alternators, I've become facinated with that technology. The automotive alternator, like a slingshot orbital maneuver, is one of those very rare cases where nature lets you have it both ways, seemingly defying physics. (The role of a generator or alternator is the same; the engine turns them and using the energy of rotation, they product direct-current electricity to power the electrical systems of the car.)

The principle of a generator is very simple and intuitive. A uniform magnetic field is created by coils of wire and soft iron cores, called "pole pieces". A bunch of coils of wire are rotated in the magnetic field. The coils cutting through the magnetic field create voltage in the coils which drives current. Now a single wire loop rotated in a magnetic field would product a sine wave AC current, so the rotating part of the generator is made up of a whole bunch of coils at different orientations. Brushes and contacts (together called a commutator) connect the one coil that's cutting through the field the most together with the generator output wires, so you get a more or less steady voltage out. The voltage of the generator is regulated by adjusting how much current is in the magnet coils (called field coils).

By the way, an interesting fact about generators is that if you apply electric current to what is normally the generator output, the generator will run like a motor.

Generators tend to be heavy because to increase their output, the rotating coils must be made of heavier wire, and the pole pieces tend to be heavy as well. The current to the field wires is supplied from the generator's output. The magnetic pole pieces retain some magnetism even when the generator isn't operating, so a generator is self-exciting; it can produce current if the rotor is spun from the outside.

An alternator is a slick way to do the same job that the generator does, more efficiently, but to create alternators it required good semiconductors. The general principle is the same, a coil of wire moving within a magnetic field produces a voltage in the wire. However, in an alternator, it's the magnetic field that moves and the coils stay still. The center part of a an alternator, called the "rotor", is two halves sandwiched together with coils in between the halves so that as it turns, each coil of wire in the outer portion of the alternator gets rapidly alternating magnetic fields. These coils are called the "stator". (There are good photos of a rotor and stator here, and a little farther down is an electrical schematic of the alternator.)

The engine of the car turns the rotor, and as the rapidly varying magnetic fields continually pass by the coils in the stator, they cause current to "slosh" back and forth. This sloshing would produce current that flowed in both directions (AC, or alternating current) except that the stator coils are then connected to a series of diodes set up as rectifier, which are arranged such that current can only flow out in one direction. There are typically three separate sets of coils and each one has a diode going in each direction so that each "push" from the magnetic field moves current out of the alternator in the correct direction, so none of the energy is lost.

Some of the current from each coil is tapped to provide current to the rotor magnet coils. The amount of current is controlled by the alternator "regulator", which adjusts the current to make the alternator output voltage as close as possible to a pre-determined value, typically 14.4V in a car. The alternator spinning produces output current which produces current in the magnet which produces current...which almost sounds like perpetual motion. It is a positive feedback system, except there is an external source of energy, the rotor which is being forcibly spun by the engine.

Interestingly, one disadvantage of an alternator is that the way the rotor is made, the alternator doesn't have any residual magnetism, so if you spin an alternator without an external source of current, there's no field coil to start generating output current. The way typical alternators work is when the ignition key is turned on, battery voltage is applied to the alternator warning light. The other side of the alternator light is connected to the positive side of the field coil in the alternator. (This can be clearly seen here, in a diagram on Speedy Jim's VW web site.) Since the field coils are essentially a short circuit at this point, the alternator light lights up this is when you turn the key to "on" but before you start the engine. The light lighting up pushes a small amount of current through the field coils in the rotor. When the engine starts, the (now energized) rotor spins, pushing current through the stator coils, producing voltage at the alternator output, which pushes more current through the rotor, which produces more current in the stator coils, et cetera. This continues until the voltage at D+ is at the same voltage as the battery, which means the alternator is now producing all the field current it needs. This also has the effect of making the alternator light go out, since B+ and D+ (the points on either side of the alternator light) are at the same voltage.

The story so far: Current through the alternator light provies a small start-up current to the rotor. The spinnning of the engine provides energy which initiates a positive feedback loop that raises the voltage in the alternator to a pre-determined level, after which the regulator starts limiting the rotor current to keep the output voltage at exactly that level.

On problem with this system is that while the alternator light will detect a catastrophic failure of the alternator, it won't necessarily detect that the alternator is producing not quite enough current to run the engine. This happened to me once, I was driving along fine and the first thing I noticed was the tachometer stopped working. Because of this problem with the warning light, that was, of course, after the battery was run most of the way down.

Now, back to the beetle. The generator (or alternator) in the beetle is driven by a pulley attached to the crankshaft, and at its other end drives the main engine cooling fan. Here's a by beetle's engine partially taken apart:

The top pulley of the belt is on the generator. The other end of the generator goes into the fan shroud where it drives the cooling fan.

To increase electrical output, in 1974 the volkswagen beetle went to an alternator rather than a generator for all of these reasons. To increase the electrical capacity of my car, I will be installing one at some point. To get some of the parts, not necessarily to buy an alternator to use, I bought a beetle alternator on ebay, shown here with the cooling fan but without the pulley:



You'll notice that unlike the generator shown above, the alternator is fatter at the pulley end than the generator is. The support pedestal for the alternator must provide space for this, and the carburetor and the fuel pump must provide for this extra required size.

You can sort of see the parts of the alternator here. Looking in the holes at the end of the alternator, around the edge you can see the copper-colored stator coils. Just inside of that is the rotor.

The alternator I have appears to not have a regulator installed:

I guess this is an externally regulated alternator? Or perhaps one where the regulator has been removed?

As far as buying an alternator to use, I probably will buy one new. California Import Parts has some nice alternators with install kits, including some 75 amp ones (all the late 1970s beetles came with a 55 amp alternator as stock. However, in the process of researching this post, I came across a company selling a 95-amp beetle alternator. Maybe a birthday present?


exploding diagram

2008 January 22 23:51

Working on my own exploded diagram of the beetle's right rear axle assembly:



From left to right along the top, the objects are the stub axle, inner spacer, spacer ring and roller bearing outer race together, roller bearing inner ring, and outer spacer. The bearing retainer is to the lower right with the bolts.


checkmate

2008 January 22 22:54

The items came today to finally hook up the Sirius radio to the Taurus radio.

Here's the Sirius Direct FM adapter and two cables to adapt the Ford connectors to normal and back to Ford-style that I got from Crutchfield:



Here they are, the radio finally connected:

You'll notice that you can't see the interface box for the adapter in this photo. That's because the people that designed the adapter assumed that the radion connection was in the front of the car too, so the cable that goes from the adapter to the Sirius radio cradle is only 6 feet long. The only place where all the wires reach is when the box is next to the back seat.

That was my "garage" work for today. Upstairs work consisted of putting shelves in the closet so that we don't have a giant pile of random hats/scarves/gloves and can't find any that match.

Sunday I put cardboard flaps on the doors in the garage to help block cold air from coming in.


re-commencing countdown

2008 January 20 19:05

I'm finally back working on the beetle again; of course, the coldest day of the winter.

Workbench before cleaning it off:

Ready to begin work:

The axle tied up to the frame of the car to get it out of the way:

I was able to push the stub axle out this far:

Here's the stub axle on the work bench. This is what the drive axle bolts to, so when grinding out the bolt, what I was trying to save was this part.

The whole assembly without the axle. The silver ring around the hole is the outer spacer.

On the left is the center race of the roller bearing (which is the outer bearing). On the right is the outer spacer.

The housing where you can see the rollers of the roller bearing. The tube you can see past the middle of the bearing is the inner spacer sleeve.


radio endgame

2008 January 19 21:57

Now that I know where the radio connection is, I ordered the hardware to patch the Sirius radio into the car. Principly I need the direct FM adampter from Sirius, but also two adapters to adapt Ford's non-standard antenna connector to it. Both pieces of hardware should arrive next week.

For now, I disconnected the cable from the car's normal antenna and I taped the transmitter wire from the Siriuc car kit across the antenna jack on the radio box in the trunk. It works really well; we haven't heard any static at all on it. However, we can't listen to terrestrial radio with the current setup.





At the bottom right corner of the radio box is the antenna input connector. Just to the left of it is a long, multi-pin connector with no cord connected to it. That's where an optional trunk CD changer plugs in when it's installed.


The water heater is in the basement!

2008 January 17 23:56

Real progress on the Sirus radio thing today. It occured to me today that perhaps there is a pre-made piece of wiring harness that interfaces to the wiring in the Taurus to connect the Sirius radio the way I want. So while we were in Knoxville today, I stopped by some stores to try to find such a thing. The only really helpful visit was to Circuit City, who had that general kind of thing, but not for our year of car. One piece of information I took away from that store was a brand name of car stero connection equipment, Axxess.

That didn't quite get me what I want, so I started looking first for our model, and then for the piece of equipment that we needed. I came across installer.com, which didn't have something that said it was for a 2006 Taurus, but did have a widget for a 2005 Taurus, called a FRDR-AUX. That page seems like it's for our car, but the diagram of the radio shows an antenna jack, which our radio doesn't have in the dash unit, which is why I'm looking for this product in the first place. I'm also suspicious, because the instructions talk about 13 and 14 pin connectors, and the connector on the back of the radio that I saw looked like 20 pins to me.

Logjamelectronics.com also has a FRDR-AUX available, which actually mentions the 2006 Taurus, so we're in luck! No more diagrams and no more information, though.

The problem with these two advertisements is that they say their adapter plugs into the data connector on the radio that would normally go to an auxilliary CD changer. We don't have a CD changer, but there's also no empty connectors on the back of the radio. Something doesn't add up.

Still thrashing around, I finally find it available at the manufacturer's web site. It's more expensive there, no surprise. They have an installation diagram, which contains a crucial piece of information that I hadn't found anywhere else: REAR MOUNTED TUNER AMPLIFIER PACK.

So the heart of the radio is in the trunk, which is why the radio in the dash board didn't have the right connectors and didn't make any sense--it's just the head unit.





And here are the connectors:

Now that I know where the bloody radio is, this job will be much more straightforward.


acoustic browser

2008 January 16 08:12

One of my friends at UHACC pointed me to a neat Firefox plugin called UnPlug. It scans web pages for embedded video content and allows you to save the content files locally. Like if you wanted to download something from YouTube so that you could play it from your hard drive, this tool would do that.

One thing you have to remember is that it must be invoked explicitly. It doesn't change anything in your normal browsing. It must be invoked either from Firefox's "Tools" menu or from the little icon that appears:


yesterday and today

2008 January 16 00:17

yesterday: cyberspace: I uploaded latest version of the work I did on the beetle during the fall of 2006. It's still under construction, and it's too long; I need to split it up so it doesn't take so long to load. It now has over 70 photos.

garage: I tried to get behind the radio in the car, but I failed.

Today: garage: I managed to get the radio out, but I didn't find what I expected. I have perhaps an interim plan.

basement: I consolidate mice, moved NeXT monitors, and moved bicyles.

cyberspace: This morning I finished sorting my browser bookmarks. For the first time in years, they're fairly carefully sorted into categories.


new kid on the block

2008 January 15 21:50

There's a new laptop on the block.

Apparently, the "MacBook Air" was just announced at MacWorld. It's only 3 pounds, no spinning optical drive. It doesn't have a built-in ethernet port, if you need that feature, you use a USB ethernet adapter.

I have to say that this goes to my top 3 next laptops just because I always loved both of my iBooks. The reason that I got a PC laptop the last time I bought a new laptop was because I was tired of not having browser plugins because I was running PowerPC Linux. There are many companies that distribute binaries of their software products, like Flash players and Adobe pdf reader for Intel Linux, but not any other processor brand. But now that Apples run Intel CPUs, that's no longer a problem.