49

As other have pointed out, the main utility is to allow easier cleaning of the tank cars from sediment (solid precipitates). Usually, there is a drain in the lowest point. The reason that it is in the middle is that in this way, you can allow double the incline compared to if you had the drain at one of the ends for the same height. For example, if the ...


13

Same reason the Corsair fighter has bent wings. Makes clearances easier. Look at the lumpy, sticky-outy things on a tank car. You have the trucks/bogeys at the end bottom... and the massive fill valve and work safety area at center top. Lowering the center is advantageous to the car's clearance envelope, allowing it to have more tank volume in the same ...


10

So any sediment will collect there as part of cleaning. Then other designs have a more pronounced bend to allow for the bogies and also keep the height down - some tunnels are lower.


2

Even though the spur gear tooth is moved by one rotation, there is a force associated with it which is related to the friction (or in general the load on the spur gear). To simplify things, let's assume that the system is in steady state (i.e. no angular acceleration). In that case you don't need to worry about inertial effects. So, lets assume that the ...


2

Usually internal dimensions have arrows pointing out and external dimensions with arrows pointing in. But I find the dimensions obvious even when there are just angled lines marking the points as the figure or object makes it clear. Knowing first angle, third angle does help.


1

When you are operating a trimmer you have a mass of about 10 gr moving side to side. Let's assume that the amplitude of the motion is about 0.1mm, and that the frequency is f= 500Hz. So the blade will be vibrating: $$x(t) = X\cdot \sin(2\pi f t)$$ That means that is velocity will be: $$\dot{x}(t) = (2\pi f)X\cdot \cos(2\pi f t)$$ and the acceleration will be:...


1

To expand on comments: This drawing is a little bit sloppy. As it's a clearance hole, it should just indicate thru diameter and both diameter and depth of cbore. Takes almost no effort in any remotely modern CAD. When I did some mechanical design, I wouldn't be allowed to do this. Might receive a call from the prototype shop asking me to clarify my intention,...


1

First of all, the two methods you suggested (buying pad materials and spring+damper) are not necessarily different. Usually the different pad materials that can be bought, (mainly) modify the spring constant in the structure. Additionally, although there are methods of targeting specific frequencies, in most cases they are not very useful. The reason, is ...


1

Pressurizing oxygen, especially for medical use requires a purpose built compressor. Other compressors add oil that can damage the lungs and catch fire. Oil-less diaphragm compressors are better, but may be damaged by pure oxygen and are also not rated for medical use. Pressurizing oxygen is not a good DIY project. A different solution to consider is to ...


Only top voted, non community-wiki answers of a minimum length are eligible