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Member #150164

Member Since: September 8, 2010

Country: United States

  • The sneezeBot Detects when someone is about to sneeze, then scares the snot out of them. It has already saved Sparkfun hundreds of dollars in shorted out electronics by preventing sneezes.

  • “I bet I can keep this motor from spinning with my bare hands, it can’t have that much torque.” - famous last words of a Sparkfun robotics designer.

  • HeeksCAD or HeekksCNC (HeeksCAD + tool path generation). I have found this to be more intuitive than FreeCAD, but I just downloaded the latest version, and am going to give it another try.

    For everything else I use Blender It has: 3D modeling, animation, rendering, motion tracking, video editing, FX, built in Python, game engine, physics engine, etc.

  • Don’t know of any, but Scilab (which is like MATLAB and NOT LabVIEW) has an add on “gateway” that lets you connect to it from LabVIEW. Haven’t used it, but it looks like it lets you do advanced calculations with the data you collect. Might be useful.

  • I’ll have to give that one a try too. Thanks!

  • For anyone who cannot afford to buy a copy of Matlab, Scilab from scilab.org is a good, free alternative. Scilab is a powerful Numerical Computation program and much of the syntax is even compatible with and can import Matlab files.

  • The use of servo or stepper motors is application specific.
    Steppers: 100W or less,
    Servo: 200W or more,
    Either: 100W to 200W
    See http://www.geckodrive.com/ark-4/faq.html

  • You could possibly add resistors in series with this board so that it only sees 51V max, but I have not tried it.
    The chip for current sensing is limited to 60V. I do not know what placing 2 in series would do with a higher voltage.
    Some other information that might help:
    The voltage sense is simply a voltage divider, in this case 3 resistors in series to get the needed resistance values (4.7k + 10k = 14.7k and 1k).
    The voltage divider equation states: Vout = Vin(Rout/Rtotal) or Vout = 51(1/14.7) = 3.47 the proper voltage for your 3.5V microcontroller, which is actually doing the voltage measuring. This board simply scales it down to a “safe” range.
    If all you need to measure is voltage, you could use some precision resistors and design it for your needs using the above equation. But a word of caution:
    Scaling down is actually a little risky. Resistors have no over-voltage protection. If you get a voltage spike (back EMF, etc.) you could damage your micro-controller. I would recommend using an optoisolator or other such device with this chip.
    With this circuit, just resistors, or both you are also changing the overall circuit by adding resistance in parallel and/or series with the load. Depending on the application this may or may not matter.
    Whatever you do, calculate the effect on voltage and current through each component.

  • I love Open Source Hardware and Software so I made a 3D copy of the logo, added some lights and uploaded a 3D render on the Open Hardware Summit Forum on the “this thread” linked by Eric-Montreal in his post above.

  • Actually, I am a Mechanical Engineer and there are many applications that use gears like that. There are even asymmetrical gears that are non-circular.

No public wish lists :(