Questions tagged [mechanical]
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162 questions
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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, ...
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4
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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?
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5
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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?
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2
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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:
...
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3
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USB A mechanical orientation?
This concerns a USB A socket on a PCB.
Is there a standard or preferred orientation of the polarization tab, either up or down?
The picture shows one with tab towards the top
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14
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7
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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 ...
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10
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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 ...
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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,...
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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 ...
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11
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2
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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 ...
- 1,937
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2
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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 ...
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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 ...
- 38.5k
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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 ...
- 203
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6
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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 ...
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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 ...
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Putting far more mechanical energy into a generator than its electrical load
Funny how I was pondering about this question for a long part of the day yesterday, and today I was at stackoverflow and in the box with the featured questions from other SE sites this very related ...
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9
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hardware for pushing buttons
Many times I want my computer to interface old hardware. Such as radio, light switch, etc. This mostly involves pushing pressing and moving various buttons and switches.
I don't want to buy new ...
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Understanding a mechanical drawing
I'm trying to understand this mechanical drawing. (Another one. I asked a question about mechanical drawings a while back.)
I can work out most of the dimensions, but the mount pads are confusing me. ...
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1
answer
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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 ...
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6
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1
answer
6k
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What is the usable area (for connectors) of a PCI Express card bracket?
I have a number of awkwardly shaped connectors that I need to cram into a single PCI Express slot metal bracket without any of them colliding with the host PC case's metalwork. The connectors are a ...
user98663
6
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2
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Servicing mechanical selector switches / rotary encoders
After 15 years of use, one of my Alps mechanical selector switches (metal contact spring dragging across metal tracks) had developed oxidised/dirty contacts.
After some cleaning with alcohol and ...
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6
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1
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683
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Most robust way to stiffen a thin PCB
I am designing a tool to be used for in-house product testing & development, part of the tool is a "probe" that is inserted between the end of an AA battery and the end of its holder (effectively ...
- 2,535
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3
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Are there strong but insulative screws?
Common through-hole power semiconductor devices, like TO-220 and TO-247, can be mounted to a heatsink by running a screw through the hole in the device. However, on TO-220 the hole is often ...
- 17.7k
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How are air-core inductors typically constructed?
I'm considering learning to build air-core inductors for power applications.
For example, I presently want a .5-1 mH choke capable of handling 50 amps for two seconds. Winding my own air-core seems ...
- 17.7k
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3
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Confusing PAD layout in datasheet
I am planning to use a Right Angle RGB LED EASV3015RGBA0 and here is the package dimension and recommended soldering pad:
Top matches with LED image(see the anode mark). Bottom is consistent with top....
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2
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3k
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Easier-to-machine alternative to pogo pins?
My project has a rectangular 5 x 6 grid, 1mm pitch pin header. Unfortunately, it needs to be cycled by the user over 300 times!
We've looked at pogo pins, because of the high cycle count, but the ...
- 1,504
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2
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2k
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Electronically controlled pneumatic lift, or something similar
Need to be able to firmly lift about 110Lbs (~50Kgs) weight, through a distance of upto 12 inches. The weight can be considered to be a flat & square wooden board, hinged to a flat platform, with ...
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Where can I get a small cheap linear actuator?
First, I should clarify: I am not looking for much power or much precision. I am looking for the cheapest thing I can plug into an arduino. I am just looking for stuff I can use for prototyping/proof-...
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1
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How to mount pcb with IEC320-C14 power entry connector inside enclosure
I am making a PCB which has one IEC320-C14 and one IEC320-C13 connector on it (Like this one). The PCB will be quite small, just large enough for some sensing circuitry; between 5 and 8 square inches. ...
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Motor that allows threaded rod to pass through
Is there a motor that can travel linearly up and down a threaded rod. I already know that you can attach a motor to the end of a threaded rod and make a nut travel along the threaded rod but this is ...
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Electronics can fail due to overheating, overvoltage, and mechanical stress. Are there other causes? [closed]
My experience with power electronics failures have generally fallen into three categories: overvoltage, overheating, or mechanical failures.
Each might have manifold sub-causes, of course. ...
- 17.7k
4
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Driving relay directly from optocoupler, what is best?
I'm designing a smart socket using an ESP-32 and a mechanical relay that can drive 5A at 240VAC. Following typical relay driving circuits, I would like to use an optocoupler between the MCU and relay. ...
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2
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Breadboard minimum lead length
What's the minimum lead length for a component in order to reliably connect with solderless breadboard contacts?
Reading specs on cables, relays LEDs, and other components, what should I take as the ...
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1
answer
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Small-ish (sub-centimeter) latching/locking connector for multiple (~4) isolated wires not bundled into the same plug
This is more mechanics than electronics but I didn't find a StackExchange site that would be better fit for it, so here goes:
I'm wondering if there is a type of "standard" connector that ...
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4
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1
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PCB Quality Issue
We made some 6 layers PCB boards (4.5" x 4.5") recently. But we have concerns about the quality. When pressing/bending/twisting the boards with very small force by hands, we can hear very ...
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Mechanically, is a latching switch always a momentary switch?
I am looking for a switch that (mechanically, not by circuit design) is first a momentary switch and then latches down when depressed far enough to be a maintained switch.
Do all latching switches ...
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4
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1
answer
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Is it possible to control and reverse the direction of a dc motor through a headphone socket?
Yesterday, I found that it was possible to control a servo using a headphone socket with a fairly simple circuit.
I've got a project where I need to to control a dc motor via a headphone socket. Is ...
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1
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20A or 30A fuse in 200A fuse clips -- is nesting reducers OK?
So, I am trying to figure out the cleanest way to make a 20A or 30A tap from a 200A circuit (single hot + neutral) that is being run through a fusible safety switch (NEMA style, as this is in the USA),...
- 9,018
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8
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How can I solder or mount this potentiometer on a PCB?
I need to use this potentiometer:
(Vishay 534-11103)
…on my board but I don't know how I can do that. I appreciate any ideas or replacement suggestions.
Manufacturer's datasheet link here.
As asked ...
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3
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4
answers
703
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Help me decode this mechanical drawing of an SD card PCB layout
I'm trying to understand this mechanical drawing so I can create a layout for it in gEDA PCB.
Specifically on page 4. I've already managed to place GND 1 and GND 2; those were fairly simple to work ...
- 32.2k
3
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7
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30k
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Gerber to DXF converter
What's a good utility to convert gerbers to DXF/DWG?
The reason I ask: I'd like to create gerbers to give to mechanical engineers for use in SolidWorks to look for interference due to solder fillets ...
- 703
3
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2
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Electro-Mechanical Connection: from screw straight up to electrical-wire?
I am developing a system that includes aircraft cables with threaded studs - screw endings that are used for mounting. Here is a picture of the stud connected to a cable:
Now I am searching for an ...
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1
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2k
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Mechanically strong way to connect wires T-junction way
I have an existing LED light curtain but I would like to redo it in more robust way. It has a main cable with 6 branches hanging down like this:
...
- 1,057
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3
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What is this type of motor called?
Firstly some background:
I would like to make a magnetic stirrer, like the ones they use in chemistry labs:
A small bar magnet sits inside the glass jar, while another bar magnet, attached to a ...
- 27.6k
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1
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Why does the X-box 360 controller battery pack have an integrated breaker contact?
People owning an X-box 360 with wireless controllers came across a phenomenon where older controllers were switching off randomly while playing or if they were moved too quickly. Me and everyone I ...
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2
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How is a display with colored cylinders instead of flip-discs / flip-dots called?
The Rossio railway station in Lisbon (Portugal) uses little colored cylinders for parts of their displays (marked in red).
I'd be really interested in getting more information about them, but I ...
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1
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Electromagnetic energy harvesting designing problems
We designed a very simple energy harvester made of a little magnet that moves inside a coil.
We have a vibrating environment moving at 12 Hz with 10 millimeters peak-to-peak. Our pcb will be ...
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3
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1
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Flex Cracking for 0402 MLCCs
Is there any data to show that 0402s are relatively flex crack resistant due to their size?
I can find lots of references about 0805 and larger capacitors cracking due to board flex, but I can't find ...
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3
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How to limit current in order to power small car radiator fan with laptop charger?
I'm trying to do a makeshift small grinder/sander out of a car radiator fan, but I want to power it up with a laptop charger for convenience.
Since it's a salvaged fan, I wasn't able to look up its ...
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1
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3k
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electronically activated mechanical release mechanism
I’m hacking a toy and would like to fire a spring loaded sponge missile. I’m having trouble googling for some sort of PCB mounted mechanical latch. Or any type of tiny mechanical mechanism that I ...
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