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    Compression of methane

    I do not know what range automotive O2 sensors operate in. You need to keep your O2 content below 2% as far as I know, to stay in a safe range. Our sensors ran in contact with the gas stream itself, sampling 2-5 cfh. fairly simple concept: sensor- meter-alarm. The high oxygen alarm needs to be...
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    Compression of methane

    The BTU content of your methane can vary greatly, from barely hot enough to sustain combustion to blue hot flames. PLEASE, if you compress any flammable gas, include an oxygen sensor on the compressor suction (intake) line to prevent a dangerously explosive mix from being put into your...
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    Mechanical prototyping options

    Yes it does! I went ahead and ordered a fair selection of it, so I shall report how it works. Some manufacturer in Germany or Sweden used to sell a prototyping kit that was packaged in a cabinet. I used one a long time back at an employer far, far, away but for the life of me I cannot remember...
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    Submersible bilge pump

    I thought that might be your intent. An underwater ROV in quadcopter form...ought to be a masters thesis in hydrodynamics. and yes, you will have to feed the motor controllers a signal they can understand, so be sure to get controllers that will take a PWM signal. In addition the controllers...
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    Submersible bilge pump

    Just so we are clear -I believe you mean a PWM signal. I have wired a number of bilge pumps and am not aware of an RC control capable bilge pump or one that is meant to operate at anything less than 100% of capacity. They are merely intended to be made inexpensively and run reliably. The only...
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    Mechanical prototyping options

    I have been looking for quite some time for a source of high quality prototyping parts that I can use to quickly make small to medium sized physical models without having to resort to making one-off parts which eat up time and materials. I think I have found the source here...
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    Invention prototype - help please with bent half tube

    You are correct. You can use exhaust header tubing pre-bent 90 or 180 degrees and then cut carefully with a bandsaw. While you show no dimensions, as long as it is less than 4 or 5 inch diameter, it should be fairly common. Some possible suppliers would be...
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    Recommended software for converting 2D images to 3D CAD model.

    Are you looking for a software program that can automatically convert 2D to 3D, or with the aid of an experienced CAD operator? To extrapolate 3D from 2D for visualization purposes, maybe... To create a 3D file accurate enough to be useful in building parts, there is a lot of information that...
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    What material is best to build a floating bicycle?

    It's a pontoon boat with a bicycle mounted on it. No real reason to change from standard materials used by the boating industry. Aluminum frame, stainless for the metal bits that spend the most time in the water. PVC, HPDE and Delrin for the plastic parts. I am skeptical about the usefulness of...
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    Traversing a square tube.

    if you put the wheels in the corners that would serve to keep the vehicle centered in the tube. That would make things much easier when traversing the inside of the tube. You might look @ as well...Inuktun does this job very well.
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    Motor Selection to Operate Golf Cart Steering Wheel

    Put a torque wrench on the nut that holds the steering wheel on the column and measure the input torque. As far as the motor to turn the wheel, I would think about using a couple of sprockets and a chain to drive it from a stepper with an encoder or a servo motor so you can get some positional...
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    Is 32 really too old to begin higher math?

    I returned to mathematics at age 50 following a rather undistinguished attempt in my teens. I was successful enough to earn a couple of engineering degrees, and these forums were instrumental in my success. I would think that @ 32, it would be a breeze.The more you do it, the easier it becomes...
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    How do I size a hydraulic motor to fit a 12 propeller to move water?

    Hi Steve, Surplus will have better prices than Grainger. The only reservation I have about this plan is the fact that every time you change power from one form into another yoiu lose efficiency. "pushing against a varying total dynamic head from 1 foot up to 18 feet. "...
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    Designing a clay disk launcher

    Do_All White Wing Automatic Trap. Battery operated. Works every time. No engineering required. I have built claybird throwers in the past. If you have a machine shop and a lot of time, it is an interesting enterprise. If you actually want to shoot instead of tinkering with the machine I...
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    Courses Online Math Courses?

    A Google search for "online college math courses" might be a good start. I would suggest that you inquire with your advisor to make sure that the institution that you attend will allow you to take courses elsewhere to get your last 6 hrs and then award you a degree. Some require that your last...
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    How to remotely control 4 DC motors?

    Do you need to control remotely by radio control? if so, then you'll just need a 4 channel remote control unit as used with either RC planes or cars and 4 motor controllers (bi-directional if needed...something like this: RC unit:
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    In pursuit of genius

    I completed 2 BS degrees with all of my upper-level classes online. It is much more difficult than taking the same class in a face-2-face setting, but it can be done. I would suggest that you try to deal with your mental health issues rather than merely retreating into yourself. If your goal...
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    Please criticize my REU personal statement

    It's looking good, but I would suggest the following changes- (Yes it is nitpicking but very often small changes can make big differences-I've edited a lot of copy) paragraph 3: "summer's" (possessive) should be summers (plural). Paragraph 4: Why did you suddenly decide to quit using any...
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    Hovering just above rock bottom. Academic Failure requesting help.

    I was in your situation 35 years ago. It's not a lot of fun. Feeling like a failure doesn't suck as bad as actually being one. You can salvage this. Therefore I am going to say to you what I wish someone had said to me (and that I had listened) then: You said: "Ok, let's assume, I somehow...
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    What is the meaning of material requirements?

    Let us take the question apart and see if we can find what they are asking... "Discuss and identify the material requirements for the component" <how do they want you to do this? ---> by relating the material property requirements to the service requirements <the service requirements which...
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    Engineering Technician

    I graduated from an Engineering Technology program in May 2010. If you are interested in pursuing ET as a career choice, there are some things you need to look in to. Start with ABET's discussion of the two programs: then take a look...
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    Linear actuators for mechanical project

    Dependent on the duty cycle required you could possibly overvolt these @ 24VDC and get the 100mm/sec required. If the actuators need to run more than intermittently, I would contact ServoCity about their recommendations...
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    Strength of Square Steel Tubing

    The strongest tube will have a round cross-section. I have never seen triangular steel tube offered for sale. A triangular cross section would be very expensive to produce and mechanically inferior to a square tube. For more information about what is available you might look at some of the...
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    Propeller - need to calculate the area

    If I am not mistaken, propellers are designed with a particular airfoil profile. This site: has both a PDF and the Excel sheet for a NACA 4412 airfoil. Therre are several other pages and the forum may be helpful to you as well. This site used to...
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    Have you ever asked yourself what would happen if you drill a hole into the earth's s

    The gravity component is an excellent calculus problem..... There's a bit of thermo...some fluid mechanics...a bunch of free body diagrams...several chapters of a good physics book...and a lot of educated guesses. This is a 3 pizza problem. I'm going to Dominos.
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    Strength of Square Steel Tubing

    What you need is a good simple mechanics of materials or strength of materials book, but it is hard to pick out 'just" what you need (which is all about beams) to find the answer without working through a bunch of material. if you can find a copy of "Strength and Stiffness of Engineering...
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    Experimental Fluid Mechanics Videos Series

    Thanks very much for stickying these, as well as the mentions of other resources. I am sharing them with the other members of my Applied Fluid Mechanics class. Great stuff. So few instructors bother to set up experiments to augment their lectures these days these films are a real treasure...
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    Need Help CMOS signal divider cuircuit

    No offense, but: Asking vague questions is a sure-fire way to minimize the amount of interest shown in your problem. I would suggest you remember that you are asking people to give up some of their time and mental energy to help you. Therefore, if you pose your question in an interesting way...
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    Which CAD Program Should I Learn?

    Fred Garvin said: "I came up on Pro-E and let me tell ya, PTC's documentation was the worst I had ever seen." I just bought MathCAD from PTC and while the interface is much more intuitive than MatLab and others...the documentation and support truly does suck. There are no good books that I...
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    Job and age

    "define old" Anyone 20 years older than me. 52 now defines the middle of 'middle aged' since I just reached 52. in 10 years, the median point of middle age will be miraculously moved to 62. The only really good thing about getting 'old' is that there are more 'younger women' every day...