Pete W
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How to work on big CAD project in team?
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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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How do I connect a 3mm water tube to a plastic box?
5 votes

If you don't care it being a little flimsy and just want quick, and the plastic is not too brittle: Use a barbed fitting with a straight thread on the outside, e.g. #10-32 of M5x.8 (these sizes happen ...

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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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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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How would I drop something directly in the middle of a vertical pipe?
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4 votes

Illustration following up from the comments We used vacuum to hold the ball bearing being dropped, from above. The ball was hand placed up against the output port of a manifold. Around it was open air....

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What are disadvantages if increasing the gain Kd for a PD(Proportional Plus Derivative ) controller
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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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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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Given flow rate of an orifice at one pressure, how do I calculate flow rate for a different pressure?
3 votes

Here is a reference from RoyMech, see section under "Orifice Flow Meter". The setup has the orifice placed in a pipe. Below is a similar, perhaps simpler, expression, from Jobson 1955, part ...

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Heat Deflection VS Coefficient of Thermal Expansion?
Accepted answer
3 votes

CTE characterizes dimensional change, with no load. It corresponds to a relatively fundamental physical principle, making it easy to use in a design calculation Heat Deflection test characterizes the ...

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What does "crs" mean in structural engineering / construction?
3 votes

Does not apply to this example, but just for completeness: I've also seen CRS as an abbreviation for cold-rolled steel in a material callout in machine drawings, e.g. "1018 CRS".

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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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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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Aluminum or Copper, which one is better to control and maintain the temperature?
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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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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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Fun Force Problem - Basic Structure of Two beams supporting weight
2 votes

To follow up on answer by NMech: I suspect if this were built, it would be necessary to have tension adjustment, due to elasticity of the tarp. Then, the sag and any 3D "catenary type" shape ...

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How do I read this schematic drawing notation for a drill hole?
2 votes

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 ...

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Rubber that remains Elastic in Hot and Dry Application
2 votes

TLDR: look at Viton / FKM PTFE has poor mechanical stability, would be careful whether to use it in most sealing apps (unless it has mechanical backup). Look at other fluoroelastomers, in particular ...

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Why are many compliant mechanisms only flexible in the joints?
2 votes

This looks like a wire edm part for those fine interior features. My guess is the design on the thin cuts was optimized for that process - i.e. constant width cut except at the entry holes, which are ...

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Reducing vibration coming from the floor while at sleep
2 votes

A number of years ago I was in a similar situation. As kamran says, the entire building is involved. Before going further, I would point out that whether or not you are able to ignore it / whether ...

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How to measure water output over time - any better solutions than tipping bucket gauge?
2 votes

With infinite budget, there are fantastic thermal micro-flow sensors, though they too have issues for drip-drip type situations. One thought, still same overall concept as the tipping bucket, could be ...

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How to make screws stay tight under high vibration?
2 votes

"split lock" spring washers are nearly worthless for serious torque or vibration. Belleville type lock washers are better, especially if serrated. The best by far, amazing actually, at least ...

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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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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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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 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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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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