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51

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 ...


25

From the "Solo Traveler" patent: A more specific object of the present invention is to provide a lid having an opening formed therethrough to enable drinking, and having a recess formed in the lid adjacent the opening to accommodate the upper lip of one drinking from the cup This is also illustrated in the patent diagrams. I came across this interesting ...


23

Most bridges (and overpasses) are built to cross over something. With a few notable exceptions, most of these "somethings" are relatively long perpendicular to the desired crossing direction and fairly narrow parallel to it. Therefore a simple "two directional" bridge best meets the needs of the engineering problem. Engineers always try to solve a problem ...


19

The simplest answer to the question is "because the motorcycle gets in its own way" Take a look at this picture of a trials motorcycle; it has perhaps the smallest of turning circles available in a motorcycle of a given length: And here's a picture of a typical bicycle steering/suspension setup: On a motorcycle, it's fairly universal to have the ...


17

Once the cylinder is released and starts to accelerate downward, the rotating flyweights should pivot upwards to a certain degree (as shown in the drawing) and should act as a drag on each of the motors' rotor shafts and thus a drag on the falling cylinder No, there is no reason for them to pivot upwards. The gravity pulls the flyweights with the same ...


16

A bicycle usually weights about 18 pounds versus an average of 180 pounds for a motorcycle. In tight turns a bicycle can easily be controlled by the rider shifting their body's center of mass as needed to nudge the bicycle to turn or correct extra overturning moments, by leaning in or out of the turn while playing with the handle bar. The weight of front ...


14

An ideal dropout design would...... OK, already there you've gone into the weeds. There is no ideal dropout design. Engineering real world things is a balance of tradeoffs. You have to balance the mechanical aspects of the dropout like you mentioned, but you also have to factor in the price of the drop out itself, the material properties of the dropout ...


13

In general, each tooth of an involute gear is made up of two curves: the involute curve and the root fillet. The involute curve is essential for gears to operate properly, and allows power to be smoothly transmitted from one gear to the other. The root fillet on the other hand is not involved directly with power transmission or the kinematics of the gears (i....


13

See the .gif below! EDIT: You may need to enable visibility of these handles if they're not on by default - it depends on your default profile/settings.


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 ...


12

Sorry for not taking your "Thin Hollow Brick-Shaped Object" as an example - I felt a standard notched test specimen would illustrate the principle more clearly: It can be seen that adding external radii to the test sample has no effect on the stress. In this example, cutting even more material away from the corners would make no difference to the failure of ...


11

In itself putting paper inside a glass will make very little difference. Glass is a brittle material and tends to fail by shock and point loading. Its static tensile strength is actually pretty good. What will help is packing paper between the glasses as it will help prevent them coming into contact with each other and dampen vibration and impact forces. ...


10

The earliest CRT displays were in fact round. However, that was more due to manufacturing tradeoffs of making large glass envelopes with vacuum inside than a desire for the display area to be round. Rectangular makes more sense than round for a variety of reasons: It's what people want to look at. We use rectangular pieces of paper. Photographs are ...


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.


8

Before I start, let me disclose that I don't know a lot about the details of infrastructure projects or your file format, but I think the general considerations are fairly universal. There are a number of considerations when providing your digital model to a contractor, and in my work I have decided to offer them my model in some situations, but not in ...


8

Multi-way bridges are rare for river crossings for the reasons you describe; however, they are seen as a component of highway interchanges, usually when left entrances/exits are present or access ramps have been "braided" into an existing system interchange, or where a SPUI has been built over an existing divided highway. Viaducts over railroad tracks or ...


8

I use polypropylene glycol in my CO2 laser tube under florescent lights and have not had any problems. It also comes with the added benefits of freeze protection and corrosion protection. If you would still like to block out the light you can use black hdpe tubing for plumbing and helical wrap the tube with blue masking tape. You could also spray paint the ...


8

It's a combination of 1, 3, 4, the product development cycle, and the nature of the product. 1 - Damage in materials is a cumulative process, the product of hundreds or thousands of little events (e.g. the tightening and loosening of the belts) or one big event (a crash). So, the product has to be designed to always have a certain damage capacity ...


8

Filling inside the cup with paper is just to lock in the wrapping of the same paper around the glass. It also offers coverage and protection of the rim of the glass. Because of the integrated, all-around coverage the whole package remains intact in the box with no chance of clinking against each other and it renders strength to the box as well. It is even ...


8

I'll approach this from a different perspective to the other answers: Pushbikes have no limits on the steering range because they don't need to add the complexity and weight. They're simple, light, and traditional, so include only the features necessary. Turning the bars more than a few degrees while riding along at any decent speed isn't needed, bu it may ...


7

Honey dippers work by using the viscosity of the liquid to raise a small amount of the liquid from a reservoir. Spoons work by trapping the small amount of liquid in a gravity well. Spoons therefore will work even when the liquid has low viscosity. The honey dipper method only works with appreciable amounts of liquid when that liquid has high viscosity. ...


7

Below is simple table for designing snap-fit joints from Bayer Snap-Fit Joints for Plastics a Design Guide, please consult the pdf for more info. As I understand your joint is C cross section with 1st type. You should also check for spherical joint clearance should be y/2. y = (permissible) deflection (=undercut), E = (permissible) strain in the outer ...


7

When the timer reaches zero, the microwave tube is turned off. Depending on your house wiring, this large reduction in load may allow the line voltage to rise a bit. The fan, which continues to run for a few seconds in order to get rid of the built-up heat, speeds up a bit as well.


7

Are you bound to the shape/configuration of part you constructed in your question? If not, a simple 3-way pneumatic solenoid valve would make this very simple and leak proof(relatively speaking). They are inexpensive too.(eBay) You would have an input and the valve will allow flow through one outlet and then energize the solenoid and you will get flow ...


7

While it is an interesting idea, I don't think a "static treadmill" is going to give you results similar to walking. A PFTE(teflon) surface would be really low friction, but I think there are some bigger issues you may need to address first. Walking is essentially a repeated process of balancing, tipping, and re-balancing. The algorithms your brain uses to ...


7

Most soda cans in the US are on the order of 0.1 mm thick according to the sources I've seen. So 0.25 mm seems plausible to me, assuming that you made no errors in your calculations.


7

Flywheels are used in space, but not for storage of energy. They are used for attitude adjustment, as the spinning of a large mass has significant implications in an object which is free to move. Unlike on Earth, where a flywheel or gyro can be spun up against the force holding it in place (bolted to foundations), and change in spin speed will cause the ...


7

Mainly cost difference. And also, a fan is sufficient for the job. The problem being solved is thermal stratification. That's caused by a lack of vertical mixing; the warm air rises to the top, the cold air sinks. Normally, there's quite a bit of movement in the first two metres or so from the ground - thermal stratification starts when the ceiling gets to ...


7

In the ones pictured, there are no trailing axles - they are a 2-6-0 and a "tenwheeler" 4-6-0 respectively. The ones shown have the firebox between the two rear drive axles. .That was an evolution of the earlier 4-4-0 arrangement. In later 4-6-0, "Prairie" 2-6-2 and "pacific" 4-6-2s and tank engines with those configurations, ...


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