Member postings for Geoff Theasby

From PPPrune -

"RUDDER/ELEVATOR BALANCE WEIGHT - REMOVAL/INSTALLATION
1. General
A. This procedure includes removal and installation of balance weights for
the rudder and elevator while control surface is still installed on the
airplane. Balance weights can be made of tungsten or depleted uranium.
WARNING: THE RUDDER AND ELEVATOR MUST BE PROPERLY BALANCED AT ALL TIMES.
AN OUTBOARD ELEVATOR OR RUDDER THAT DOES NOT MEET THE
REQUIREMENTS SPECIFIED IN 51-80-02 OR 51-80-03 OF THE
STRUCTURAL REPAIR MANUAL CAN PRODUCE UNDESIRABLE FLUTTER AND
DYNAMIC INSTABILITY WHICH COULD AFFECT FLIGHT SAFETY.
B. Depleted Uranium Balance Weights
(1) Some balance weights on outboard elevator and upper rudder are made
from depleted uranium, which is a naturally occuring uranium that
has been "depleted" of most of the isotope U235. This remaining
low-level radioactive uranium, similar to other heavy metals, is
toxic if ingested, absorbed, or inhaled into the body. Those
weights are identified with legends permanently stamped into the
surface of each weight, to assure special handling during
maintenance. Protective coatings have been electro-plated on the
weights to contain the depleted uranium. If those coatings are
penetrated, certain precautionary measures are required to minimize
the small health risk.
WARNING: REWORK, SUCH AS FILING, SANDING OR MACHINING, THAT WOULD
DAMAGE THE PLATING OR REMOVE ANY BASE METAL IS PROHIBITED.
INHALATION OR INGESTION OF FILINGS, DUST, ETC., FROM THE
WEIGHTS MAY BE HARMFUL.
(2) Limited repair of damaged or corroded weights can be accomplished
safely if the procedures in subject 51-20-03, hazardous materials,
of the Structural Repair manual are used.
(3) Replacement of uranium balance weights with tungsten balance weights
can be obtained from Structural Repair manual (51-20-03)."

Depleted uranium WAS used, but now Tungsten, I believe.

Geoff

One of the oft-repeated film clips from the attack on Pearl Harbour shows an intense jet of black smoke shooting from the funnel of a warship. I imagine that a bomb or torpedo has just exploded in the boiler room, and some of the blast went through the furnaces.

Geoff

Yes Dave. If you have the experience and the skill. In a start-up I was involved in, we equipped the Chief Engineer with used professional gear from Iwatsu, Kokusai, Anritsu etc., plus Marconi, H-P and Rohde & Schwarz, that's where I learned to use a Spectrum Analyser. Both the MD and Chief were brilliant, then there was me, who did everything else! Great times.

Geoff

Stewart of Reading have been in business for years and sell good, reasonably priced, used test equipment. (No relation)

Geoff

I'm late to this debate, but I believe I can add to it. I'm writing an article on these little scopes, having been a radio amateur for 50 years, in possession of a traditional (Philips) scope, and the author of other published articles on simple test gear using your computer sound card and downloaded software, mostly for free! Furthermore, I recently acquired an AVO 8, one of my life's ambitions. The difficulty of obtaining the right battery is of no consequence, since any cheap (£5) digital multimeter will be more accurate for testing resistors than the AVO. Surely most people have more than just the one multimeter?

Geoff

A similar anvil was on Chesterfield Market on Thursday. The foot was left as it came, so it was clearly a piece of heavy duty steel rail.

Geoff

"Off the wall" suggestion... I've seen things like this which give access to a chimney flue, for inspection or cleaning purposes. A removable panel a few inches square.

Geoff

Here here, NDIY! The world is full of people who can only see disadvantages, in mobile phones, 'visual disturbance' like cellphone masts, solar panels, battery technology, pollution, etc. Yesterday I heard a sensible idea for people who have to park on the street. Plug your EV into a street light! Wonderful lateral thinking! Also, charge it up whilst at work. 8 hours spent unused in the office car park, yeah? The hydrogen economy is a dead end because the i/c engine has hundreds of moving parts, an electric motor has one! Fuel cells are much more likely.

Geoff

Camphor is a rust inhibitor, so spread old-fashioned mothballs around.

Geoff

Google your camera details for the manual.

Geoff

Norelem have a HUGE catalogue of Standard Parts.

Geoff

OK, found it now.

Bear in mind that conventional electric motors lose torque as voltage is reduced, leading to thyristor control as mentioned, which cuts off more or less of the AC mains waveform reducing the speed but not the torque by reducing the time that AC power is 'ON' during half the 50 Hz supply waveform. Modern versions use Triacs, to control both halves of the AC waveform. I built such a device for my single phase power drill. I now have a pulse width modulated speed control to control a Gauge 1 locomotive, running at a nominal 12 volts, which works the same way, with DC.

I find no problem with the article by Mr Gawthorpe, except that he states that no flip-flops or gates are used in his device. I would say that there are, but built from discrete semiconductors, not integrated circuits. It doesn't help that a mains motor is rewired for 12 volts, and an inverter built, this just confuses the matter. An inverter would be used with a AC mains motor, not with a 12 volt car alternator.

Geoff

I can't find it now, but I recall it. I also recall a lecture at Sandown Park a few years ago, regarding turning a car alternator into a variable speed motor. I think it used a power oscillator, but this isn't my field.

Geoff

Yes, Russell, however I was never convinced that CO2 was a major problem. Methane, from cattle, from ourselves and melting permafrost, is more potent, as are several other common chemicals. Our grandchildren will be more concerned about the debts we are currently loading on to them, but that's another matter.

Geoff

Duncan, alcohol is a food! Ho Ho.

At the moment, CO2 is less of a problem than NOx or particulates A hydrogen economy also assumes no Nox from i/c engines, but this applies only if the H is burned in oxygen, not if burned in air. (Air being 80% nitrogen)

Geoff

No, no, no! Not Hydrogen! It's expensive to make and store, and the process is inefficient. Fuel cells, yes, but using methanol or similar hydrocarbon. Cheap, easy to contain, low emissions. Not commercially available, not because it has been 'suppressed' by the oil giants, but the i/c engine is entrenched, and well understood.

Geoff

Howard, "With regard to commercial vehicles, the attempts to power buses electrically have never come to anything, Spinning up an electrically powered flywheel, or charging, whilst at stops, has never been implemented successfully, even for urban transport. "

Apart from trolley buses, which were very successful, and still used all over Europe, there are hybrid buses operating NOW here in Sheffield. They set off on battery power, and the smaller-than-normal engine cuts in afterwards. The smaller engine reduces emissions. As for transferring the pollution to power stations, that is so, but it is easier to clean the output of a power station than do it individually at each vehicle.

As for flywheel power, check on Parry People Movers.

Geoff

Martin, we may have to change our lifestyles somewhat. I/c engined cars can do local, fill them up once a month, or long distance, fill them up daily/weekly. We are not condemned to having two cars either. The average commute is 20 miles daily. So, have an electric car used daily, and hire an i/c engined car for holidays or the odd long trip. Or join a car club. Hybrids are an answer tor those who want one car for both, but it means hauling round an unused battery or an unused i/c engine if you are using the alternative power source. In horse drawn days, people were happy to hire a horse or carriage, my family used to run a livery stables in Keighley before WWI. Most people's cars sit unused between 9 and 5 or whilst sleeping. So, rent when needed, save the hassle of ownership, costs incurred only when needed, and no large investment depreciating in your drive most of the time.

LED lights will make little difference to the power consumption. Anyway, they are a safety feature, so that others can see you.

The Enfield 8000 could barely make it to the pub & back. But see the, "Who killed the Electric Car" documentary.

Nowadays the average commute is well within the range of an EV, plus they don't only need to be charged up at home. Most cars spend the working day in a car park with their drivers at work nearby. They could be charged then, too. If all suitably oriented buildings, not just houses but factories, warehouses, industrial sheds etc. were built with solar PV roofs, which nowadays don't need direct sunlight to work, and the rest retro-fitted, problem solved!

Geoff