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    H-Bridge help

    So I am wiring up a H-bridge for a small electric motor for a robotics project and am a little confused. This is the only schematic that I can find for this H-bridge. There is a pdf on that site that is...
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    Hda vs hdb vs hd*

    So I got into an argument with a buddy over the following: I originally inserted a hard drive into my system and it was labeled hda, what i hadn't notice was that it was on the master pin setting now when i switched the pin to the slave setting and rebooted it showed it as hdb are the two...
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    AC motor Capacitors

    I picked up a good and cheap AC motor that came with its own capacitors <not wired in though> The capacitors are these and this is the diagram on the motor" [Broken] Now I tried putting this together but...
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    Fischer-Tropsch process

    Not sure if this is the right place for this, but here we go. During the Fischer-Tropsch process to create synthetic oils one of the byproducts is water. Is this water removed from the oil somehow? Also I have been told from some of the engineers that I work with that synthetic oils absorb...
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    Variable Pitch Fans

    I was hoping that someone here would be able to help me understand variable pitch blade systems for fans/turbines and how they work I have already searched the internet quite a bit without much luck There are a few mechanical drawings but they leave a lot to the imagination Any help is...
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    Sound Card Line-In

    I have been reading up using the Line-in on my computers sound card and the pogram XOSCOPE to be able to do some various measurement/analyzing But before I attempt to actually plug anything together i want to make sure I don't wreck my soundcard I have found that some soundcards have the...
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    Composite Design

    I am not sure if this is exactly the right place but it works either way. I am interested in learning more about Composite Design Techniques mainly fiber based materials (carbon, kevlar, fiberglass, ect...) does anyone here know of any good resources/books that focus predominantly upon this...
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    Parabolic Leaf Springs

    Hello I am trying to find more information about parabolic leaf spring designs. I have allready learned linear leaf spring design, and I am curious to know how parabolic differs. (besides higher powers) Thanks
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    Shaft Key Sizing

    For my Design of Machine Elements class this problem is being posed. This is exactly as the problem is stated. The torque on the 400mm -diameter shaft connecting the flywheel with the jaw mechanism should never go above 700kN m. Dimension a copper square tapered key so that the shaft is not...
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    Homemade Parachute for Model Rocket

    Ok I am sure the title caught your attention, but it is not for me, it is for my cat, just kidding. It will actually be for a model rocket I am building. I would like to design a ram-air parachute to control a descending rocket (toggles will be attached to either servos or linear actuators and...
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    Port Programming

    I am interested in learning how to control various motors via my linux computer for robotics projects and possible cnc machines it seems that serial ports are the most prevalently used for basic robot control does anyone have any suggestions on where to start? thanks
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    Old Laptop Monitor

    Well I recently just tore apart an old laptop and salvaged the monitor (still good) Now I am pretty sure it is nearly impossible (for me right now) to turn it into a useful desktop monitor but does anyone know of any other cool projects/ideas to do with it? thanks
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    Solar Panel question

    I have a 24Volt solar panel trickle charging a 12volt Battery My question is when the sun goes down and the solar panel isn't producing any power. Does the battery then try power the solar panel? and if so is this bad for the solar panel? --Shawn
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    Hex head motor shaft

    on a smaller electric motor the motor output shaft is cylindrical with a hex head insert i am just directly attaching it to a small tire is there a certain type of drive shaft that anyone could recommend i thought about using an old allen wrench but had nothing to hold the drive shaft into...
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    MATLAB Matlab Question

    I am not sure if this is in the right forum but i have 2 matrices in Matlab T = [ r11, r12, r13, dx] [ r21, r22, r23, dy] [ r31, r32, r33, dz] [ 0, 0, 0, 1] T04 = [sin(theta2+theta4+theta1), cos(theta2+theta4+theta1),0, 7*cos(theta1+theta2)+4*cos(theta1)]...
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    Pressure (form) drag

    Is there a way to calculate the pressure drag on objects? without having to turn to CFD software? thanks also has anyone here ever built their own small wind/water tunnels for testing? and how successful they were?
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    Fin Stabilization

    I am trying to work through the stability forces on rocket fins and understand how you need laminar flow for greater stabilization but i am not sure how to accurately calculate some of these I was told that the Reynolds Equation holds true, but uses a different cross sectional area what...
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    Air Coupling

    I am trying to learn more about air coupling. That is the coupling between 2 shafts I am having a hard time finding any information on the subject matter does anyone know how these systems work and have any diagrams? thanks
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    Epoxy vs. Polyester Resin

    Can anyone give me a quick comare/contrast of Epoxy and Polyester Resins? and what application they are better for? thanks
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    Controlled Descent

    I am going to start working on the controlled descent of an amatuer rocket I want to go up to about 4000ft and then be able to have a controlled descent to a specific location. I am still very very early in the process and just brainstorming ideas about GPS locators and what not. has anyone...
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    Bike Tire

    On standard road bike tires sometimes they put a soft/flexible kevlar layer to protect against puncture. I was thinking about putting in in hard/rigid kevlar layer to also protect against puncture, I know that this will make the actual tire stiffer and harder to deform, which could be a bonus...
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    Radio Transmission

    can anyone explain to me why radio reception/tv reception ect.. come in more clearly when i hold the antenna? i am assuming my body is acting as a better receiver but can someone actually explain why? thank you shawn small
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    Bulb fiasco

    so i am trying to find taillight/ brake light bulbs i need a 6v 10 w (12 v 20 w) and a 6 v 5 w (12 v 10 w) and autostores are worthless in milwaukee none of the carriers have the Wattage listed they have the CP i amnot sure what the CP is on these bulbs? is there a direct relationship to...
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    Laying my carbon/kevlar fabric

    when laying my carbon/kevlar fabric i constantly have the problem of it sticking to my gloves which is quite annoying and makes it hard to handle should i be using specialy coated gloves? do they make such a thing? or is there a "lay-up" procedure that anyone knows of for laying composite...
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    Robotics Program

    is there any programs out there where you can enter a layout of a room for a small robot? like the room dimensions, basic furniture placement ect... or can you do this with C or Pbasic or some similiar program? thanks
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    Grad. School Advice

    I will be starting my Senior year of a Mechanical Engineering degree. I want to go to grad school. I really want to find a program that is based on robotics in an astronautical environment i don't think such programs exist anywhere though or if they do i just don't know about them yet. i...
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    Torch Brazing

    Not sure if this should be here or in materials.... So I am attempting to braze 2 flat pieces of aluminum I apply a copious amount of flux I believe I am heating teh metals thoroughly my braze is not flowing into any of the joints ever i have tried numerous times once I even ended up...
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    Buying either a stick electrode arc welder

    i am looking into buying either a stick electrode arc welder or a semi-automatic flux spool fed arc welder does anyone have suggestions about using either/or? thanks
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    Sun Tracker

    Does anyone have any suggestions of how to make a device follow the sun acrossed the sky? It will be a solar panel mounted on a satellite dish acting as a large sunlight collector, but it needs to be aligned with the sun for optimal power. Thanks for any input.
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    Jet Engine

    Has anyone here ever built a small Jet engine? Just generally interested in how you did it and from what parts thanks