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    Max Tolerance stack-up

    My main concern is when the pin drops down how well aligned it will be with the hole on the PCB. I can start from the pin and work my way back, assuming the Pin's axis is the main daturm.
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    Max Tolerance stack-up

    Hi, I've been reading about stacking up tolerances. It's the first time in working with them. I understand the gist of it and I've seen a few simple examples however when I move onto my project I keep getting lost as I dont know what and where do they stack and if I should just add them up or...
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    Solidworks thermal simulation: is this logical?

    Hey Guys, I'ma bump this thread with another question regarding the same model (or a very similar one). In the OP you can see the two chunks of metal (named heat spreader) Those pieces are 6"x6"x1", with a whopping volume of around 35 cubic inches For experiment's sake I decided to change...
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    Solidworks thermal simulation: is this logical?

    That makes perfect sense! thank you. I completely forgot to think in terms of volume rather than mass. . .for some reason I assumed the same mass since it was the same piece. . Thanks!
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    Solidworks thermal simulation: is this logical?

    I just ran 2 simulations on Solidworks, same assembly, same initial conditions on all pieces, pretty much I "Cloned" the thermal study and just changed one piece So, from the assembly above you can see the materials for most pieces, the 2 grey pieces in the center are 2 aluminum plates with a...
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    Thermal Conductivity of Springs

    Yeah, that might be it, I appreciate the quick analysis. The thing about this particular application and why we came up with this debate is because when you press down on it the temperature drops (counter-intuitively) you would assume the temperature should increase when you press down on it but...
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    Thermal Conductivity of Springs

    I agree with Akin's law of spacecraft however I am looking for EDUCATED OPINIONS, based on heat transfer laws we've learned. If you want some more details that could help do a more educated guess. Please note I am not looking for exact numbers, I am looking if there is an obvious answer or not...
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    Thermal Conductivity of Springs

    I have a question that I've been debating with some co-workers. We are using conical springs (tapered) that most of the time in our application fully compress once engaged. We are measuring minute changes in temperature and I was wondering if a spring diffuses more heat compressed or relaxed...
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    Maximizing insulation (conduction, convection and radiation)

    Hi, Its been a while since I had my thermal heat transfer classes and Im a little skeptical on what I remember. Im trying to insulate a copper block, the sides are covered by an insulating material which has a low thermal conductivity (they are touching). Howver there is a surface on the top...
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    Increasing Flow rate through system

    Hi, I'm building an experimental set-up for some heat exchanger I'm trying to analyze, I want to maximize the flow through this little piece. I have a stable temperature bath, (see picture) that has an evacuation valve on the bottom. I only took introduction to Fluid Dynamics (found it amazing...
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    Small Machined springs

    Hi, I usually buy off-the-shelf springs, however I am working on a design that requires some very specific features on each side of the spring (if possible), however this is a very small device, (its a probe). Anyways, I was thinking of getting a machined screw, as I've seen some very good...
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    Designing with Thermal expansion in mind

    Hi, Im trying to design a tubular probe thats made of stainless steel (304), from what I've read it has a Thermal expansion coefficient of around 9.6 x10^-6 in/in/F give or take on the quality. I want to fill this tube halfway with an Epoxy, however from what I've read this epoxy has a thermal...
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    How to read lots of inputs

    I dont really understand that link very well, from what I gather its a whole device in itself right? The thing is that I am trying to make a probe for a meter I already have. I already have the meter with a very good processor that can measure up to .002 C. the problem however is the actual...
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    How to read lots of inputs

    Well, the EEPRROM has a single in/out wire, a Vcc and a GND. I am still researching to see if I can share ground with the resistor, if thats the case I will only use 4 pins: 1- GND 2- Resistor 3- Vcc 4- Data In/out if its not possible I will use all 5 pins: 1 - GND 2 - Resistor 1 3 - Resistor...
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    How to read lots of inputs

    Ok, thank you for the reply. The sensors are a set of values: Each sensor has a 5 pin-interface (Only 4 pins used): Pin 1 and 2 go to a temperature-dependant resistor (so an analog device) Pin 3,4 go to an EEPROM, that stores the calibration values of the resistor in place (it contains the...
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    How to read lots of inputs

    Hi, Im working on a project that could potentially do 2 of the following. I am a mechanical Engineer and I dont know much about electrical engineering, bu talking to a friend of mine who is still studying EE, he gave me his input which I felt was not the best option, I hope you guys can help me...
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    Logical Channel detection

    Each channel has a thermistor in it, so it only reads resistance. So analgo voltage I would assume. Yes i could add a micro-controller to scan and make decisions, however I would like to keep it as simple as possible. I am looking for the simplest solution.
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    Logical Channel detection

    Hi, I am designing a PCB with multiple 2-pos DF13 connectors in it (Like 50+). at the end of the board there is a 10 pos. cable. My intent is that the user (me) connects up to 9 channels in any position I like (I have 50 possible choices). However, this board is connected to another PCB that...
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    Pin-screen Matrix feedback

    Ok, I think I polished my question. I'll make it simple and quick. Can someone tell me what type of sensor I can use to measure distance traveled by a pin? Look at the drawing, I hope its clear.
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    Pin-screen Matrix feedback

    Hi, This is kind of a hobbyist project or something along those lines. I am trying to build a pin-screen Similar to that, or with whatever conifguration of pins. But I want it to provide electrical feedback so that I can map out where each pin is on a Z-position (their X-Y coordinates are...
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    Torque required by motor

    no no, axis of rotation goes normal (orthogonal) to the face of the disk, it is the shaft of the servo at the bottom that makes the whole thing rotate. So just T=aI, where I is the sum of moments and a is the desired speed. . .hopefully this will get me going
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    Torque required by motor

    The axis of rotation is pretty much the center of the bottom disk (and its supposed to be aligned with the beam and the top disk). Ok, so then I'll start making specs on what alpha I want for this system. Thank you again, you've been a lot of help
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    Torque required by motor

    Thank you for the reply Simon, Ok, so the moment of inertia would just be the sum of inertias of each component? (2 disks with I=1/2 mr^2) + (beam with I=1/12 mr^2) ? and I assume use the parallel axis theorem to move all inertias down to the bottom disk? (+1/2 md^2) and what would I do with...
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    Torque required by motor

    Hi, I am working on a project that needs some rotation around a central axis. I was looking over at some Servos but I dont know how to calculate the torque required by the servo. I was thinking of doing a simple free body diagram, but as I was drawing it I realized the forces are on the Z axis...
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    Weird PCB stuff

    they are red, and yes they are hooked up correctly, in fact if I swap LEDs from one wire to another they light up normally, but on those 3 particular channels (wires) since there is no voltage drop, the LEDs either dont light up or burn out. *EDIT* reading previous posts, i didnt see some of...
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    Weird PCB stuff

    how can I troubleshoot it? I have little experience with this, like in theory it should work, in paper, in eagle, in LTspice
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    Weird PCB stuff

    I did not measure the current, I edited the post to reflect that. the PCB schematic is not complicated, its basically the first drawing I posted up there (just that instead of the LEDs replace with the same DF13 connector with 5 pins that connect to the 5 LEDs . I just wanted to show where I...
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    Weird PCB stuff

    that would tell me the current is zero, since V=iR however, here is how it looks (like the actual EAGLE stuff): I have some current mirrors to regulate the current on all LEDs, and I have (as mentioned) the resistors with 90 ohms each, all verified by multimeter. I dont have the spec...
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    Weird PCB stuff

    Hi, I recently designed a PCB in EAGLE, and I got it manufactured and I had all the pieces Sufrace Mounted on it, put it in the oven, everything seems fine and dandy, but I already killed 3 LEDs because of some weird thing going on. I have 5 different LEDs conneced to my circuit, the leds run...
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    Not sure about finding velocity with this equation

    I am a little confused, you say you are moving the disc 5 meters? or is that just an example? what you are doing is rotating the disc about its center axis I assume? If so, you cant use the "linear" versions of those equations, basically replace V with theta dot (angular velocity, aka...
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