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Everything posted by Geoff_H
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NSW motor vehicle licence at 75year old
Geoff_H replied to Geoff_H's topic in Student Pilot & Further Learning
Bruce, may I be so crude as to ask your age? I have just started to allow one trusted garage to do work on my car's. Still do simple stuff, stuff that takes less than a few hours. I absoluely agree with the having to get up to get the tools I forgot 😁 -
Are parts available for Camit2200 engines? How reliable are they?
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Similiar speed but different mach numbers?!
Geoff_H replied to SAH's topic in Aircraft General Discussion
Sorry but the speed of sound is not purely a function of the temperature. It is a function of the density! In a gas temperature is a significant contribution to the density. -
NSW motor vehicle licence at 75year old
Geoff_H replied to Geoff_H's topic in Student Pilot & Further Learning
My car does not have a wheelbrace. Nor a spare wheel. Destroyed two wheels recently. Drove about 10km on flats at 80km. Not the normal precise steering it normally has. -
NSW motor vehicle licence at 75year old
Geoff_H replied to Geoff_H's topic in Student Pilot & Further Learning
Only go to a garage that has a torque limiter attached to a rattle gun. It is what I do with my alloy wheels, observe the setting and attachment of the device. And when they say that they won't let the car back on the road without them as tight as possible, inform them of their knowledge inadequacies and publish the company on social media. -
NSW motor vehicle licence at 75year old
Geoff_H replied to Geoff_H's topic in Student Pilot & Further Learning
The stud is a spring. Steel is elastic and by extending it just a little very large forces can be generated to hold two things together. How much force is a function of pressure in a cylinder or sideways forces on wheels. The true way to determine the force is to measure the bolt extension. Difficult on small bolts, easily done on large bolts. The extension on small bolts is infered by the torque applied to the nut. The wedge force determines the bolt force by mechanical infered calculations taking into account friction in the nut. Bolts can be over stressed particularly when it is the first 1.5 threads that take the overwhelming part of the strain. It the wheel nuts are overtightened the threads are put under stresses that will allow the thread areas of both the nut and bolt to permanently deform and eventually break the bolt or strip the thread. -
NSW motor vehicle licence at 75year old
Geoff_H replied to Geoff_H's topic in Student Pilot & Further Learning
In the 1970's I was commissioned to do a study on bolt failures. Amongst the things that I discovered was that 90% of the bolt load is taken by the first 1.5 threads. So over tightening, using the full impact force of a rattle gun just damaged the threads. The tyre service I use these days has a torque limiter on their rattle guns. I was able to use the cars wheel wrench to change the flat tyre. If your tyre fitter over tightens the bolts you are at risk of stud failure. -
NSW motor vehicle licence at 75year old
Geoff_H replied to Geoff_H's topic in Student Pilot & Further Learning
A month ago I went through one of the monster potholes in Sydney's castle hill. it damaged the drivers side front and rear tyres. Front tyres are a different size to rear tyres, so I had to buy 4 new tyres. $2000. I also got the experience of driving on run flats at 80km/hr, the vehicle was controlable, but would not have been at any faster speed. -
NSW motor vehicle licence at 75year old
Geoff_H replied to Geoff_H's topic in Student Pilot & Further Learning
For turnover you will also need the coefficient of friction road to tyres lol. I need to a quick calc before in tear into a corner lol -
NSW motor vehicle licence at 75year old
Geoff_H replied to Geoff_H's topic in Student Pilot & Further Learning
Got my medical for Class C drivers licence yesterday. Went to DAME that has been doing my class 2 medical's. She was totally aware of my medical history, only cost $99. Good result. P.S. she is now my GP. -
NSW motor vehicle licence at 75year old
Geoff_H replied to Geoff_H's topic in Student Pilot & Further Learning
My Class 2 far exceeds the motor vehicle medical, but the beauricracy of the government prevents it from being a satisfactory substitute. -
NSW motor vehicle licence at 75year old
Geoff_H replied to Geoff_H's topic in Student Pilot & Further Learning
I did the class 2 basic a few medicals ago. My doctor required a full eye exam and report as per heavy vehicle licence. Took a lot longer than optometrist and cost $160, then my doctor charged $250 for rest. Next med I went to DAME, she did eye test and charged $250. Full class 2 cheaper and let's me night fly, not that I do much of that these days. I see that my dame does the road and maritime so I will go to her. -
Very shortly I turn 75. NSW require that I get a medical from my GP. She is requiring that I also get an optometrist report at additional cost. I have a class 2 CASA medical certificate the DAME does my eyesight at no extra cost. As a car licence can be a medical for a RAA licence this question is probably a revelamt topic for this site. Anyone had to do the 75 medical?
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I like the dual cycle engines that are becoming popular in modern vehicles. The combustion starts as an Otto then converts to a diesel cycle (using petrol). These engines are more efficient than both diesel and Otto. When you see the temperature entropy and pressure enthalpy graphs this is shown. The best reason that I like them is that Mercedes is getting 400hp out of a 2 litre engine. I feel that a small engine with that output and efficiency could be the future for aircraft. My vehicle has a 2 litre 250hp engine and gets 6.4 litre/100km, very reliably, it has a dual cycle engine. It's manufacturer was talking about dropping the less efficient diesel engine in its favour. All seems to have changed now that the "climate change religion" reigns suprime.
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What is Warnervale like these days? Is it good for doing the biannual flight review for a private pilot licence?
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Similiar speed but different mach numbers?!
Geoff_H replied to SAH's topic in Aircraft General Discussion
The speed of sound is a function of the density of the material it is being transmitted through. -
I am talking about the control systems inside the power systems not the 330kV or 500kV systems, they are very specialised systems. I was the commissioning engineer for the first Eraring 500kV switchgear. Another item that makes large spikes is the size of the wiring. The original power stations used 24/48V systems with 7/0.29 wire, modern systems use 1mm or less. Larger wiring gives larger spikes.
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CAD Design for Aircraft Project
Geoff_H replied to marianmadalin32's topic in Aircraft Building and Design Discussion
I use autocad 3D for 3D printing. I have used acad since its inception in the 1980s ( or about then). I tried a free 3d cad package but it was too hard to learn at my age, something about old dogs and new tricks. 😁 -
CAD Design for Aircraft Project
Geoff_H replied to marianmadalin32's topic in Aircraft Building and Design Discussion
30 years ago I was writing acad program files (name eludese at the moment) I was able to take an excel file and extract data and create dwg files from the excel data. The formats for acad and SLC files is well documented. I expect that pdf file format is documented. I am 74 and too old to do it these days but you should be able to find a young budding programmer that would write such a program for you, maybe even for free. It appears that the software exists, for free some of them, do a PDF to DWG search on the internet. Feel free to contact me privately if you wish -
CAD Design for Aircraft Project
Geoff_H replied to marianmadalin32's topic in Aircraft Building and Design Discussion
30 years ago I was writing acad program files (name eludese at the moment) I was able to take an excel file and extract data and create dwg files from the excel data. The formats for acad and SLC files is well documented. I expect that pdf file format is documented. I am 74 and too old to do it these days but you should be able to find a young budding programmer that would write such a program for you, maybe even for free. -
CAD Design for Aircraft Project
Geoff_H replied to marianmadalin32's topic in Aircraft Building and Design Discussion
Is your a to make SLC files? -
CAD Design for Aircraft Project
Geoff_H replied to marianmadalin32's topic in Aircraft Building and Design Discussion
Can I assume that you have pdf files and want them converted to DWG/dxf files? -
40 Years ago when I started working in power stations we used relays for control. We recorded spikes of nearly 5kV. We imposed a 5kV spike tolerance on the new electronic control gear. We didn't even consider that with the relatively slow switching of electronics a maximum tolerance to 1kV spikes. That was until Siemens forced us to accept the 1kV tolerance. The electronic control systems worked great. The moral of the story is avoid relay switching spikes and go for electronic switching as much as possible.
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Considerations in Engine Cowl Design
Geoff_H replied to skippydiesel's topic in Aircraft Building and Design Discussion
Active inlet dampers could possibly be used to regulate the amount of air into cowling for regulated cooling. Many aircraft use exit dampers, a simpler and better idea to only using as much air as necessary. But inlet dampers such as that used on some vehicles could be used. Inlet restriction may reduce airframe drag, may, but the complexity and weight penalty may negate their effect. It's just a thought, my design process has always been, "what can we do different" then suggest even stupid ideas then examine possible implementation of the stupid idea. I then usually end up seeing that things as they were traditionally designed are the best. I live by the motto that there are no stupid questions just stupid answers.