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    3D Gear models Electric Longboard thread

    If you're still considering getting the pulleys printed, it's probably worth taking a look at 3DHubs or MakeXYZ -- it should be quite a bit cheaper than professional SLA or SLS prints.
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    FVT Firmware for E-Skateboards

    There's a firmware flash option in their USB interface software. I have one or two FVTs that I can't quite get to work, so I might try flashing them and see if doing so fixes anything... (would be good to know how it differs from the regular firmware, though)
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    FVT 120A ESC Help?

    You needed to play with the throttle trim before you could calibrate the throttle? That seems a little counter-intuitive. Ijust tried sending every possible PWM signal between 1000us and 2000us in increments of 50us without any luck, so it doesn't seem like it's the throttle. Unless I'm...
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    FVT 120A ESC Help?

    I'm having issues with getting two FVT 120A ESCs I just bought working -- attempting to do a throttle calibration, but nothing happens when I hold down the SET button as I flip the switch to turn them on. Motor is plugged in, the fan turns on, and the programming card works fine. (motor beeps...
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    Screw-reinforced printed motor mount?

    I believe the IGUS stuff is really meant for things like bushings and rails; I doubt the ultimate tensile strength is significantly better than that of ABS or Nylon. Basic stress tests also won't tell you much because the limiting factor in printed parts is typically delamination and layer...
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    Estimating accelerations?

    kT's a constant, but your applied torque will fall as speed rises. If your torque was always equal to T_max you wouldn't have a top speed. ;)
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    Lipo Torkinator ESR help required

    Poking around with a multimeter is a good idea. Or, can you take a closer or better focused photo of the board, perhaps so the text on each component is readable? If you can figure out where there's a pin or something with a positive voltage only when your goped is on, it'd be easy enough to...
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    Sprocket Size Speed vs. Torque--Rookie Question...

    I think it'd actually be no, for both. For the same wheel pulley, more teeth on the motor pulley would make your board faster, not slower.
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    Post Your Electric Longboard or Electric Mountainboard Build

    I think somebody just needs to find some time to design a decent BMS... it's on my to-do list but I probably won't get around to it until the summer. In the meantime: http://endless-sphere.com/forums/viewtopic.php?f=35&t=61171
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    Drilling a keyway in a motor shaft : advice needed

    A short carbide endmill did the trick for me. It took me a couple passes but just go slow and it's pretty simple. Gives you a much nicer finish than a dremel, haha. Not that that really matters...
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    Top Speed Calc with Load

    If your mechanical setup is 100% efficient and there's no rolling resistance, your speed will creep upwards to approach the point on the graph above when (the radius of your wheel) x (force from air resistance) is equal to (your motor's torque) * (1 / your gearing ratio). A legitimate top...
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    Will this ESC + Motor Combo work?

    Your combination looks fine; the motor voltage won't be an issue. Ideally, your batteries should be able to handle 100 amps continuous; you can get your battery's maximum continuous discharge current by multiplying your discharge rating in C with your capacity in Ah. ( ie 5Ah battery * 20C...
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    Customizable Electric Longboard- Design Input

    Funny, so have I. Went to elementary school only a couple miles away. If you're looking for versatility, one suggestion I'd have is to make your motor mount rotatable; it adds an immense amount of flexibility in terms of wheel size/deck clearance/RWD vs FWD/2WD vs 1WD/goofy vs regular/etc...
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    how come it takes so many watts and 8s escs

    Misread the original post, oops. Thought he was referring to a hub motor rated for 350W. Or somewhere covered with decently paved roads. :wink:
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    how come it takes so many watts and 8s escs

    Care to share how you got 19mph? Maybe I'm missing something, but I don't see how it's possible to calculate speed from just power and weight. I'd also tend to disagree with the pneumatic vs solid tire argument, but I guess that's really dependent on terrain. Hummina, where'd you get the 1000W...
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    Step down converter for esc possible ?

    A UBEC is just a 5V/6V/7V regulator with a fancy name; essentially just the circuit you posted but with a fixed voltage. Don't see why it would be any more isolated.
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    Step down converter for esc possible ?

    If you adjust the regulator before plugging it into your controller, it shouldn't be a problem. You can glue down the pot adjustment screw if you're paranoid about it turning, but the one in your link uses a worm gear and should basically be vibration-proof. 10S lipos peak at 42v, and the...
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    Longboard 660kv motor HELP!!

    I did multiple hole patterns for tensioning, but I haven't found a need for tensioning yet; the "middle" pattern is just the calculated center-to-center for a 17:40 reduction + 3 thou; the other two are spaced at something like ctc + 8 thou and ctc - 15 thou. Turning down the trucks and clamping...
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    Longboard 660kv motor HELP!!

    I think $250 is doable. 5065 270kV motors are common and good for flat ground. I have a bunch laying around and could probably send them to you for cheap. + motor mounts, printed & polycarbonate pulleys, 6S 120A car escs, etc /shameless plug
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    3D printed parts Depository

    Just a note: my Flashforge extruder doesn't really agree with flexible filaments. The filament path isn't constrained well enough, and the filament buckles in between the drive gear and the actual hot end. I think there are printable extruders on Thingiverse that'd let you print with the...
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    Simple Charging Port (Plug n Play)

    Onloop's connector (which I think looks really, really nice) sounds like the safest bet, especially if you eventually want to upgrade your charger. @onloop I think he meant the balance leads can handle charging up to 40 amps, which shouldn't at all be a problem if your batteries are properly...
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    3D printed parts Depository

    Huh, okay. I've been having trouble tensioning the belt tightly enough so that it doesn't slip when breaking, without obvious resistance during some parts of the revolution. Bolts through my drawing?
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    3D printed parts Depository

    Ah, should've made myself clearer. I meant the wheel doesn't seem concentric; so it sort of "wobbles" as it turns, and the effective center-to-center distance between the wheel pulley and the motor pulley changes.
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    3D printed parts Depository

    Bump? Wheel runout has been a pretty major obstacle for tensioning my mounts; really curious about whether others have had the same problem, and how they tackled or solved it.
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    Here come the clones..

    The fan grill looks exactly like the one on the FVT 120A car ESC.
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