# Tag Info

## New answers tagged mechanical-engineering

1

See the .gif below showing how you might set these mates up. You need to add another part or a sketch into your assembly with axes in the correct places, and then mate your shafts to be concentric to those axes. Here I have set the parts coincident to the front plane to also limit their axial movement.

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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.

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Your issue is that you're assuming the key and key way will have exactly the same dimensions. In reality the key will have to be slightly smaller than the keyway. What yo want to do is start with the concentricity, then use the width, or parallel mate to line up the key and keyway. This way you're not over-constraining the assembly. Solidworks sometimes ...

1

More precipitation sites initiate the higher the temperature. So you want a higher temp to have many sites. The precipitates grow faster ( become coarse) at higher temperature. But the objective is many precipitates ( high temp.) with small size ( low temp). So the temperature selection is a compromise. I think some newer precipitation stainless steels have ...

1

This is the end part of the ship during the construction and is not finished yet. This part when finished will be called Stern. The stern houses the rudder and the propellers and follows the keel. It is designed to have a streamlined narrow shape under the water to help reduce the drag of the ship and vibration due to the rotation of the propellers and ...

1

You got time & temperature switched. temperature, pressure

1

This structure as it is is not going to tip over no matter how much force you apply on the top where you have the arrow at 12 inches. Unless the force is so much that the pipe is going to break or crush under the compression stress. Because the arrow falls within the footprint of your hanger. Let's do a quick calculation: Let's say you hang a weight of P ...

0

The use of the orifice plate is to optimize the jet diameter and adapt it to the possible abrasive material or the job detailing finesse requirements. The orifice which is normally of Tungsten carbide and in the industry sometimes called jewel does not control the pressure. pressure and velocity are controlled by powerful pumps. - Uses a high velocity ...

1

If you want a hight reduction ratio (such as 1:50 as mentioned in your other question), don't use spur gears. These are self-locking. Lock after cycloidal drives: https://en.wikipedia.org/wiki/Cycloidal_drive If your rpm's are low, the unbalanced property might not hurt so much.

0

The built-up to momentum in the mass of gas flowing out of the nuzzle and building the design exit Mach and stability of the combustion is better left alone from the disruption of on-off cycles. Avoiding flame blow out in the combustion chamber and continuity in vector thrust navigation lend better to long bursts.

1

A Brayton-cycle gas turbine compressor presents a large mass flow of air to the combustors at a pressure that varies with the speed of the blades and their pitch. For the moment we assume that both of these are constant. Heat is added to the compressed air by burning fuel with it in the combustors and the resulting hot gas is free to expand out towards and ...

1

You're making the assumption, that all wheels are rolling without slip. Is it a front wheel driven vehicle? Slip could cause the deviations you see. So, what directional speed are you looking for? Forward velocity? At the mid plane? Use the average of the two longitudinal speeds of the wheels (wheel rate/radius). Lateral? Should be zero of you have no ...

1

That should be correct. The rotational velocities and accelerations in the motor, caused by turning the output shaft, increase by r. Along with the acceleration, the reaction torque in the motor increases by the same amount. The reduction ratio will also apply on this torque and and hence increase it again by r at the output shaft.

1

The curve is not linear. $s =$ actual deflection (mm) $h_o =$ total possible deflection (mm) $F =$ actual load (N) $F_c =$ designed limit load (N) Here you can see the original archive with the ploted graph from one industry (I usualy use this material for reference about these type of spring). I don't know the exact formula. But the reasoning ...

1

I have a K&E LOVAR 100 ft base tape. And the ‘brochure’ specs. LOVAR per K&E is quoted at 0.44ppm/C. NIST discusses the difference in CTE amongst commercial “alloys of steel” as being only a few percent +/- and negligible. Steel is approximately 12-13ppm/C. So, 0.44ppm +/- “a few percent” of 0.44ppm I believe is the answer to your question. In ...

1

The forged composite material used by Lamborghini and Calloway (a.k.a. "forged carbon") has a higher modulus and tensile strength than other composite materials like glass fibers and even traditional carbon fiber composites made with twill or satin weaves. The "randomness" of the fiber orientation in the "forged carbon" composite produces a stronger part in ...

5

If that is true, then would not be better off just to remove the whole setup and have the axis of rotation free from bearings ... Ball bearings change a system from sliding friction (as in a journal bearing) to rolling friction which is usually considerably less. Ball bearings prevent wear in one place as would occur with a horizontal rotating axis at the ...

0

so that there are not any inner or outers rings and therefore the friction problem would be removed from the beginning The axis needs to be supported somehow (i.e. in direct contact with the support) or it would be "floating in space". As the later is impossible, you are forced to have the first. Usually you provide a lubricant between axis and support ...

1

The cross section of the spring wire may be what they need. If so, and we call it $D_{wire}$, this can be calculated as: $$D_{wire}=\frac{(D_{out}-D_{in})}{2}=\frac{(5.3-4.7)}{2}=0.3\text{ mm}$$

0

Redundant ; How would you pour with no gravity; the metal would just sit in the ladle after you turn it upside-down. Floating of slag/dross , and hydrogen gas ( always present to some degree) would not happen.

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It certainly does: any slag inclusions, for example, will tend to rise to the "top" surface of the casting, which hence furnishes an anisotropic distribution of inclusions in the finished part that depends on gravity. If the sprue or gate that feeds molten metal into the mold cavity is on the "top" side of the mold, then breaking the gate remnant off the ...

-2

In theory yes! But how much difference does it make, it depends on the impurities, material, and of course size of the part. Right after filling the mold, the metal is still a fluid, it means the heat transfer is carried out by conduction, (natural)convection and radiation. In the presence of a gravity field, the temperature gradient and the density ...

1

It is a spring-loaded ratchet and pawl system. the pawl mechanism is unlocked by the centripetal force of the initial rolling of the shade by a user. Here is a diagram.

1

A roller or inclined ramp clutch may be what you are talking about.

0

The restoration and maintenance of historic buildings is the subject of a post-graduate course for architects, engineers and construction managers. This link covers some aspects of small, historic building maintenance. The left panel has a chapter reference. nps.gov/tps/standards/rehabilitation/rehab/masonry01.htm

1

Building on to what was previously said, when designing a bracket or mechanical fastener based connection, my major concern would most likely be the failure of the plate or the bolt/screw. For this, you may need to consider: bolt tearout, hole yielding or general yielding/failure of the plate. Furthermore, you may also need to consider the strength of the ...

3

There is no material with zero deflection in the world. Every thing deflects, to different degrees. The best possible way to prevent a bracket from failure is to design it for the task it must do. If the load is a vibrating machine, it must be allowed to vibrate by with a frequency that is not likely going to resonate with that of the machine. if the load ...

2

Units of N, mm (for the stiffness k), and g (for the mass m) are not consistent. You need to convert these values to use in the basic equation for the frequency: $$f=\frac{1}{2*\pi} \sqrt \frac{k}{m}$$ Knowing that $1 \, N = 1 \, kg*m/s^2$, $1 \, m = 1000 \, mm$, and $1 \, kg = 1000 \, g$, you get the following: $$f=\frac{1}{2*\pi} \sqrt \frac{N/mm*((1 kg*m/... 1 Simple answer is that you can't because you have to take derivative of the position vector with respect to time which would be zero in the case of the vector you described (It simply doesn't contain the temporal information). 0 If you only have a general postion vector that describes the path of the object, then it's impossible to derive the velocity vector. Here I try to demonstrate it: Since the point masses are dimensionless, we can consider two different point masses at the exact same location. Point mass m_1 moves with velocity v_1 so the point mass m_2 with v_2, ... 0 High pressure applications typically involve elliptic head. This is the shape with the lowest stress from all shapes possible. See the graph at the bottom of 6th page of this paper https://www.google.com/url?sa=t&source=web&rct=j&url=https://pdfs.semanticscholar.org/bbce/eebd3ef103fe37d7f0185d193005d194e83c.pdf&ved=... 2 The coordinate transformation of polar to cartesian is given by:$$\begin{pmatrix} r \\ \theta \end{pmatrix} = \begin{pmatrix} \cos\theta & \sin\theta \\ -\sin\theta & \cos\theta \end{pmatrix} \begin{pmatrix} x \\ y \end{pmatrix}$$For a point mass, moving along a path in space, we can define an arbitrary point, and call it origine. Notice that the ... 1 I would advise staying away from the conical, as this is for low pressure applications. This would lead to more thermal flashing in the vessel. You would also want to consider sch 80 with high pressure steam and condensate applications. 0 One Newton is equal to 101.971grams and one gram is 0.00980665N. In free undamped vibration we have to convert grams to Newtons,$$ \omega_n = \sqrt \frac{k}{0.00980665*m_{grams}} T= \frac{2\pi}{\omega_n}  f_n=\frac{1}{T}= \frac{\omega_n}{2\pi} Edit Going over my answer after @John answer, I realize that I was wrong. I leave my answer ...

5

Great question! Water absolutely is used as a lubricant in some power generating systems. For example many Francis style turbines use their feed water as the primary lubricant and coolant of the bottom main bearing. (In the old Loeffel turbines, that bearing was typically made of lignum vitae wood, and could last up to 100 years in near constant use). ...

0

Diesel and heater oil are the same thing , the tiny difference is the additive package ( a fraction of 1 % of the total). Diesel may have a better additive to prevent wax from crystallizing and plugging lines in cold weather , for example. From time to time in various locations there may be different limits on sulfur ; depending on the refinery this may or ...

0

Lubricity is a material quality Look into the difficulties they have had removing sulfur from diesel fuel. Sulfur was added (or not removed) to increase the lubricity of the diesel fuel, to improve freedom of motion in injection pumps. That being missing is a hardship for older diesel engines whose pumps depend on it. The fuel is basically the same in ...

0

Diesel engines can run on a wide variety of fuels, as long as the fuel provides some lubrication. https://en.wikipedia.org/wiki/Fuel_oil#Uses Residual fuel oil is less useful because it is so viscous that it has to be heated with a special heating system before use and it may contain relatively high amounts of pollutants, particularly sulfur, which forms ...

1

I suspect you may be looking for a "synchronized screw jack lift mechanism." Many sites exist when one searches using the above term. Some are not synchronized, allowing for tilt and translation and probably other movements, depending on the complexity. A commercially oriented web page provided this image: Laser cutters use this method of bed movement as ...

13

Sea water is about the worst thing in the world to put in a metallic mechanical device. As noted , corrosion would be horrendous ; dissimilar metals, stray currents , etc. Wind turbine gearing is an exceptionally demanding application ; EP ( extreme pressure ) lubes are needed with graphite and/or moly sulfide, etc. I am sure a major problem addressed by ...

58

The whole point of lubrication is to keep the two surfaces almost apart. Water has low viscosity in comparison to oil-based lubricants, which means that it forms a thinner film (electrohydrodynamic film thickness) between the two surfaces; the thinner the film, the greater the chance of direct physical contact between the parts. So, the higher viscosity ...

0

Long ago , the IL Air National Guard flew F51 and F84 ; at summer camp they shared the same dedicated airfield. In the distance you could see an F84 line up on a straight approach to land; Occasionally an F51 would make a 90 degree turn and land in front of the F84. When the F84 made its large turn it was so far away that you couldn't see it unless you were ...

1

A low speed biplane will have a smaller turn radius than a jet, for the same reason that a car can make a smaller radius turn at low speeds. For "normal" non-aerobatic flight, the standard time to make a horizontal turns is the same for all aircraft: 3 degrees per second, or 2 minutes for a full 360 degree circle. If a jet is flying at 5 times the speed of ...

2

It's difficult to determine from the photo which parts are moving and which parts are dependent on another part for specific movement. If you get proportionately smaller travel per revolution of the main knob, the other parts of the assembly could be a differential screw mechanism. Differential screw mechanisms are used in micrometers, in which the main ...

3

Elastic Modulus is a property of material, not the shape of the structure. In your case it depends on the type of the paper you used and also weather the bridge walls are parallel to the paper fiber grain or perpendicular, or angled, because paper is not an isotropic material. Most likely the paper you have used is composed of randomly mixed fibers, which ...

0

If you don't want to use a mechanical fastener, I would suggest encapsulating them, by wrapping a thick adhesive around them and sticking it to the base material. You might try Sugru moldable silicone putty, or just a very thick (and non-corrosive!) RTV silicone. Make sure to prepare surfaces well! Even slight fingerprints will trash most adhesive bond ...

0

The best solution for adhering wires to things is to use rigidly attached anchor points, and then zip ties. Anchors that are part of the case, or are attached with screws are best. As I said in a comment, I haven't had good luck with those adhesive rectangle anchors. They're initially very strong, but after a few months I've seen them come dislodged by even ...

2

Depending on the gripper mechanism an the properties of the objects you want to lift, you can do it by hand calculation (ideal case). It would be much easier to give you advice if you gave information about the structure and material of object to be lifted (like rigid solids, compliant foamy things, or bulk like sand). Now I'm assuming a rigid load object ...

0

First alternative I've run into was suggested by Wasabi in a comment to my question. The video is here: https://www.youtube.com/watch?v=OdW7vhYYSdM This example uses a circular saw -- hand tool. In essence they put an accelerometer chip to control the power and braking inputs to the saw. While it doesn't stop as fast as sawstop, it triggers the halt at ...

1

The seal you are looking for is commonly called an oil rotary seal ring. I found many brands and sizes with a quick search. the range of prices for a 1-inch shaft is around \$5.

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