Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [mechanical]

154 questions
25
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4 answers

Strong adhesive to attach part to PCB

I am looking for recommendations for a strong adhesive that would be easy to apply by hand in production quantities. This is for fastening an ABS plastic riser in between two PCBs. Epoxy would work, but we would need to make sure the set time was…
BrianV
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23
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4 answers

Why use kapton tape?

I have noticed a lot of electronics use kapton tape in places where a heat resistant tape isn't necessary. Why is that so? Is it just because it's a good adhesive?
Artichoke
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23
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5 answers

What does BSC SQ mean?

I'm reading this DAC datasheet. The last page (p. 32) gives certain of the chip's dimensions, some in units of "BSC SQ". What does BSC SQ mean? Is it standard to express sizes in BSC SQ?
Randomblue
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2 answers

How do old school, electromechanical elevators work?

Today Scouting New York ran some photographs of the mechanicals of an old, working elevator that dates back to the 1920s. I was especially intrigued by this amazing picture of the control system: Can anybody explain what the heck is going on there?
Joel Spolsky
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14
votes
7 answers

Measuring small movements of a needle and syringe

My question is how to measure very small movements of a needle and syringe when injecting. When doctors inject local anaesthetic, they always aspirate (suck back) first to make sure they are not in a blood vessel. My contention, particularly if the…
Mark Stoneham
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13
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4 answers

How to package a sensor watertight in a DIY environment?

I need to measure the temperature in a terrarium and use that as an input to a temperature controller. The terrarium is quite humid, e.g. above 80%. Also the packaging should have minimal thermal mass, in order not to hinder the temperature…
Vorac
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12
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9 answers

Freely rotating part that conducts electricity to fixed part - does this exist?

Planning a design that has a 12V voltage source connected to a physical part that rotates. I need to conduct electricity from the rotating part to a fixed part which is connected (electrically isolated) to free-standing structure like a pole or a…
robobozo
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12
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11 answers

Alternatives to a classic DIP switch

I'm looking for a part that enables a user to frequently change a configuration. Right now I'm utilizing a SMD DIP switch connected to an I2C I/O expander. What bothers me is the large footprint of these components (DIP switch combined with IO…
timonsku
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11
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2 answers

Magnetic power connectors (ie. "dots") for slim power supply connection

This may be more of a mechanical question, but does anyone know what these magnetic power connectors are called? You see these on Fitbits and other IoT devices. I'm building an IoT board, that has a waterproofing requirement so a USB connector is…
Leroy105
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9
votes
2 answers

What was this completely destroyed piece?

Yesterday morning, I was preparing my tiller pilot (auto pilot for small boats) but it sounded like something was loose inside. When I opened it up, I found a damaged rubber sealing and the piece in the image below flying around loose. It is…
PMF
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9
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4 answers

Why no macroscopic electrostatic electromechanical parts?

So, I understand that relays, motors, and other electromechanical devices are almost always electromagnetic devices. Why is this? I know that electrostatic motors exist, but what makes them substantially worse than electromagnetic motors? Note that…
Hearth
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7
votes
6 answers

Track-mounted drive system

I would like to mount a slow-moving robotic "car" to a linear track of any incline from horizontal to vertical. The track should be rigid (attached to a boom if necessary) so that it can be propped up on one end or leaned against a wall to provide…
Isaac Sutherland
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3 answers

Mechanical construction of PCB. What is between the layers?

I came across an answer about the construction of a multilayer board. It included an image showing the mechanical construction of a board (see image 1.) This prompted me to think of the actual construction a bit more. Image 1: Construction of…
joojaa
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3 answers

Securing PCBs - Screws Vibrating Out

I am curious what methods are most suitable for securing PCBs. I have a large PCB which is fixed to a sheet metal enclosure using #4-40 x 1/4" stainless steel screws. The receiving end is a #4-40 captive standoff (PEM product). Initially I was not…
Jason
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6
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1 answer

Resettable mechanical switch?

I'm looking for a mechanical on/off rocker or toggle switch that can be reset to a default state and position upon the removal of power. The application is in a vehicle where I want the switch to return to a default position once the ignition is…
danpat
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