Pete W
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Rack on rack vertical force
1 votes

Assumptions: neglecting forces from gravity (weight of top part) neglecting possible effects from offset load (1) Decompose the external force into orthogonal components: $\vec{F_H} = \vec{F_N} + \...

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What is a "Unidirectional Input" (?) Closed Loop Control Algorithm Called and How Does it Work?
1 votes

SMALL SIGNAL Let's assume a typical loop. Controller and plant in forward path, unity feedback. Let's add a pre-filter. Let C = controller transfer function; P = plant transfer function; F = input ...

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Is it possible to construct geared speed and torque dials?
0 votes

Interesting puzzle. The speed dial could be something along the lines of the 'flying-ball governor' mechanism, with the travel of the sliding+rotating collar connected to another sliding non-rotating ...

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Help with design of linear actuator
0 votes

Lets take a look at how a position control system would look with a stepper + timing belt system. This won't consider loads and size of motor. Preview: It gets close. A servo-motor belt driven system ...

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Why are hydraulic systems widely used to multiply force ? won't a couple of gears do the job?
1 votes

"Can transfer force through long curved paths" - this part can in principle be done with cables, which is the technology that was used for construction equipment before hydraulics. ...

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Why does the taper on tapered-roller bearings help support axial loads?
2 votes

Another interesting feature of tapered roller bearings, is the relationship between axial and radial clearances. Bearings life is usually maximum when there is a slight interference fit -- allowing ...

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A problem from Damped free Vibrations
2 votes

I think your math is taking you to the right place. Looking at the this sketch from the problem statement, it does not look like $\dot{x}(0) = 0$ when $\phi_0=\pi/2$; for example see here. Perhaps ...

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Derivation of static & kinetic friction formula
2 votes

I think the formulas are empirical. But saying 'empirical' raises two questions: why is $\mu_k$ smaller than $\mu_s$ why is $\mu_k$ independent of velocity You can make a loose unscientific analogy ...

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What are disadvantages if increasing the gain Kd for a PD(Proportional Plus Derivative ) controller
Accepted answer
3 votes

Depending on the plant, a reduction in phase margin could happen. Here is a theoretical example. Consider a plant with a double integrator and an additional pole: $$\frac{K_1}{s^2(1+s/\omega_P)}$$ Now ...

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Flow Velocity Data Automation - Platform/Controller Selection
1 votes

Sounds like you want a 4-20mA Data Logger, which is a common category of product with many interface options and price ranges. As long as you're willing to do the scripting to sync it with whatever ...

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What is the steel used for CHC DIN912 class 12.9 exagonal bolt?
0 votes

I think all the DIN standards are now ISO. Here are references I found: Corresponding ISO standard, primary source -- ISO 898-1:2013 PDF copy of ISO 898-1:2013 from google search To indirectly address ...

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Are un-dimensioned orthographic views permitted on a standard drawing?
4 votes

Regarding the issue of repeat dimensions, at least for machine drawings as opposed to structural, reference dimensions (either in parentheses, or indicated like "12.34 REF") could be an ...

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What are some chemical reactions that failed to scale up?
1 votes

'Failed to scale up' can be a commercial thing as much as technological, will comment on that. Typically for anything novel, companies will file some but not all patents before they have ...

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Resistive divider hydraulics analogy, is this true?
1 votes

With laminar flow (and some other assumptions like fully developed flow, everything at equilibrium, newtonian fluids, and uniform viscosity throughout the system), then Poiseuille's law applies and ...

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V2 drawing interpretation
2 votes

I haven't seen that form of tolerancing, but your suggestion makes sense, that it might be min / nominal / max ; and min / max when only two numbers. I would also say same side as arrow. ...

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Why materials with preferably a negative temperature coefficient for heating elements?
3 votes

It really depends. If you have multiple heating elements (or areas within a single element), in parallel, they will end up at slightly different temperatures. If the application is temperature limited,...

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How to tune a PID controller when plant's step response looks like a ramp?
1 votes

If the response is really a ramp, i.e., a single integrator, you could use a P or PI controller. If the ship has some mass to her, then the ship's turn does not start or stop immediately -- rudder ...

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Control System Response
0 votes

Picking up from NMech's answer: For the step response, integration constants can be expressed in terms of $\zeta$ and $\omega_0$ According to swarthmore.edu Where $\omega_0 = \sqrt{\omega_1\omega_2}$ ...

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Could someone explain how a compensator shifts the root locus?
Accepted answer
0 votes

If I read it correctly (i.e. the plant has a single zero but not pole at the origin), then the issue I think is being solved, is that the plant RHP pole we are trying to manipulate is unpaired. Thus ...

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What, roughly, are the characteristics of nuclear power in grid management?
1 votes

Re: load following, from Wikipedia Modern nuclear plants with light water reactors are designed to have maneuvering capabilities in the 30-100% range with 5%/minute slope. Nuclear power plants in ...

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Equivalent viscous damper for friction damping
1 votes

I think a hydraulic device could approximate it. General concept: For each direction: a spring-loaded check valve (ie with a cracking pressure) in series with a small-diameter-tube would realize a ...

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Is electric motor torque determined by Kv or by power (watts)
1 votes

Kv is for back EMF. It is part of what you need to model the current, in addition to the resistive and inductive model of the motor windings. The current then gives your torque via Kt. This is all to ...

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How to work on big CAD project in team?
Accepted answer
12 votes

It's a massively important question. Short response: apply the concept of encapsulation. Divide into subsystems During development, assign design-ownership (distinct from project manager role, ...

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Highest point of stress in a multistage gear reducer
1 votes

As per the other answers, when teeth are uniform width, and are engaged, then pressure and shear-stress should generally be highest on the slowest moving gear. There are also impact loads as they ...

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Force control of pneumatic piston
1 votes

For a quantitative application, the electronic pressure regulator in Transistor's answer is probably the most appealing other than component cost. (It may still need another valve to move backwards, ...

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Discrete-time realization for continuous time domain controller/filter?
1 votes

For a great many engineering uses, you can approximate your idealized s-plane filter, into a z-plane equivalent, by one of the transformations mentioned in AJN's answer, using closed-form "...

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Ideal Surface finish in turning
1 votes

Simple definition of depth of cut, I believe, is the nominal difference in radius of the work before vs after the cut. This would be the roughness only when the Z feed rate was equal to (the "...

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Aluminum or Copper, which one is better to control and maintain the temperature?
Accepted answer
2 votes

Simplified analysis to compare materials, for different limiting-case applications, given the same geometry: Want max heating ramp rate, with fixed-power electric heater -- minimize Volumetric Heat (...

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How do I get a thin section slice of grooved metal to analyze groove depth under a microscope?
4 votes

There may be non-destructive options, like laser profilometers or even optical microscopy that can extract Z axis data. Check the back side too.

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Engineering Best Practice: Rev control for trial parts after release?
2 votes

When I worked at an (in theory) ISO shop, we did the same thing as the OP, and in-development designs were uncontrolled and informally and inconsistently versioned. A recent question here (talking ...

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