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  1. Thread: Malum IK

    by jwatte
    Replies
    55
    Views
    5,542

    Re: Malum IK

    https://www.youtube.com/watch?v=8fnfeuoh4s8
  2. Thread: Malum IK

    by jwatte
    Replies
    55
    Views
    5,542

    Re: Malum IK

    SO I haven't been very active on the gun thread, because I realized something else was broken, too.
    The new video transmitter, with "SmartAudio(tm)" 4800 bps half duplex interface, needs a serial...
  3. Question(s) Re: AX12-A not communicating after failed firmware recovery

    Overloading servos can die, for sure. Debugging this is going to require some effort!

    You should add an Xbee or something that can send periodic status information. For example: Every five...
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    Re: DJI releases RoboMaster S1 - Robot tank

    Look at that delicious injection-molded plastic gimbal!
    I wonder if it's separable enough to use on its own? And what the control electronics are?
    Also, seems quite comparable to a mech:


    ...
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    Re: Malum Gun Sub-thread

    Not giving up on this. Just too busy at work to make post-worthy progress.

    A dual-start worm screw, perhaps?
  6. Re: How many hours per week does your team meet to work on anything robotics related during the season?

    That's not enough really to do actual work. Just setting up and tearing down will take a significant amount of time.
    I'd rather use a single three-hour window instead of two 90-minute times.
    That...
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    Question(s) Re: Dynamanager finds mx-28t but not mx-106T

    Are you using "Dynamanager," or the specific "Dynamixel Manager" program that's part of the RoboPlus download?
  8. Re: Why are there two sets of wires going to the electromechanical brake - mobility scooter motor

    Brakes are good if you need to stop.

    Does the "mystery" motor have six total wires? And you think four of those may be going to the brake?
    If so, you might want to measure the connectivity, and...
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    Maker Media shut down

    https://www.theverge.com/2019/6/8/18657824/maker-faire-make-magazine-shut-down-layoff-diy-culture

    So ... no Maker Faire New York, I guess? :-(
  10. Replies
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    Re: Malum Gun Sub-thread

    Also: I found these: https://www.mcmaster.com/9657k412
    7554
    Not as artisanal a source as Ace Hardware, I admit, but their CAD models are pretty nice!

    Cutting a 7.7mm diameter, 3mm pitch...
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    Re: Malum Gun Sub-thread

    I'm not sure about that. By leg span when walking, maybe? but the hip-to-hip distance is only 137 millimeters -- a hair over 5". When "curled up," it's actually quite small! (Onyx was bigger...
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    Re: Malum Gun Sub-thread

    Yes, I think that's a reasonable conclusion!
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    Re: Malum Gun Sub-thread

    Right! My path of inquiry is "Dhon's design has a theretical pinch point and seems to work great in practice; what's specific about those features that make that pinch point not interfere in...
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    Re: Malum Gun Sub-thread

    @GhengisDon That's pretty fast :-)

    @giantflaw Yes, my best design so far was a gravity loader, too. (It's the one available on Shapeways.) The thing I'm trying to get away from is storing all the...
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    Re: Malum Gun Sub-thread

    @giantflaw Yes, I'm going to have to live with some indecision point mitigation. Also some bristles/velcro pads, perhaps.

    @tician I agree that toughness comes from flexing, but that's not the...
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    Re: Malum Gun Sub-thread

    In engineering in general, there's always a point of "undecidability."

    In any electronic system (even a digital one,) there is SOME signal that will lead the input buffer being in an...
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    Re: Malum Gun Sub-thread

    You know what's great? Physical simulation is great!

    7546
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    Re: Malum Gun Sub-thread

    That's good to know! (And matches what I've seen -- the BBs slide much less than I would have hoped ...)

    Separately, I built a model of the funnel, and of course ... there's another pinch point....
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    Re: Malum Gun Sub-thread

    Ha! :-)

    More like a linear bearing with cycling bearing balls, maybe? (In fact, going looking in that area might give me some more ideas?)



    Yes, that's a given in this application. I'm using...
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    Re: Malum Gun Sub-thread

    Interesting!

    My current thoughts are something like this: (Seen from above; the U shapes are where BBs fall down, and the "spiral" on the bottom feeds the BBs into the up-bent channel)

    7542
    ...
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    Re: Malum Gun Sub-thread

    A rotating wiper and a stationary hole is equivalent to a stationary wiper and a rotating hole, right?
    Because if the hole rotates, then some kind of agitator/sprocket can rotate below it without...
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    Re: Malum Gun Sub-thread

    What worked well for me before?
    A simple wiper, with BBs falling into a plain opening.
    I wonder if I could re-use this thought somehow?
  23. Replies
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    Re: Malum Gun Sub-thread

    Preloading 300 BBs in a single helix does sound interesting :-) And storing it around the barrel is a novel idea. Could look really cool!

    Meanwhile, there was still a pinch point between the...
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    Malum Gun Sub-thread

    Strapping a barrel to a gearbox and aiming it at the enemy isn't particularly hard, mechanically speaking. (Or even electrically -- either use a 10A motor driver, or use a MOSFET driven by your...
  25. Thread: Malum IK

    by jwatte
    Replies
    55
    Views
    5,542

    Re: Malum IK

    In other news, I m in love with thread milling.
    No special tapping heads. No compression holders. No need to synchronize the spindle.
    Just friggin' cut the thread!
    The thread mills don't get stuck...
  26. Re: Maker Faire 2019 Mech Warfare (WMFNY in Queens on Sept 21 and 22)

    I'm really hoping I'll be there!
    (Close to my birthday, too; good reason to duck out of town :-)
    This time with less gun jamming.

    I couldn't see from the MW sketch -- what's the area of the...
  27. Thread: Malum IK

    by jwatte
    Replies
    55
    Views
    5,542

    Re: Malum IK

    Thanks for the feedback! Truly helpful.

    Some more context: This is the result of several iterations of doing the same kinds of tests! It's good to know I'm following an established process. There...
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    Sticky: Re: Introduce yourself!

    Helios -- check out the Mech Warfare forum, it has some good threads.
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    Question(s) Re: PWM Operating Mode

    No, the MX-28 has no way to be controlled by a RC-style PWM control signal.

    The "PWM control mode" simply means that you can set the duty cycle (and thus approximately voltage/current) of the...
  30. Thread: Malum IK

    by jwatte
    Replies
    55
    Views
    5,542

    Re: Malum IK

    In my question for a better magazine / feeder system, here's what I've got so far...

    https://watte.net/malum-hopper-v3.JPG

    Why can't anything ever be easy?
  31. Thread: Malum IK

    by jwatte
    Replies
    55
    Views
    5,542

    Re: Malum IK

    Yes, but you don't want them :-) There is a fairly annoying place around the motor where the BBs catch and I ended up with about 50% dry fire.

    https://a360.co/2I5fMWB
    https://a360.co/2Qu6uXE...
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    Re: Dumb Idea: So like... what about jumpjets?

    I bet the three "editor's choice" ribbons for Bay Area Maker Faire may help open the door for NYMF :-D
  33. Question(s) Re: Do I have to unplug the balance connector from the loader before use ? (LiPo)

    The question is what the charger does when it's not powered by itself, just sitting there.
    If it goes very-high-impedance, then you can leave it plugged in without danger to the battery.
    For...
  34. Replies
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    Re: MX-64 bricked after update

    Yes, I'm using a USB2Dynamixel.

    Yes, when the bootloader somehow failed, it ended up with a partial program, which presumably ends up crashing right after boot.

    I'll probably pay the fee and...
  35. Question(s) Re: Do I have to unplug the balance connector from the loader before use ? (LiPo)

    I don't know; is it?

    How much current do you "balance" with? 0.2 amps?
    How much RDS(on) do your MOSFETs have? 100 mOhm?
    This will cause 0.02 Volts of drop between the battery and the charger.
    ...
  36. Replies
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    Re: MX-64 bricked after update

    No, they are "bricked" as in they don't work at all (although they blink when powered on.)

    Specifically, this is the chain of events (reproduced on two servos):

    1) Servo communicates fine at 1...
  37. Thread: Ax12/18 pid

    by jwatte
    Replies
    9
    Views
    3,920

    Re: Ax12/18 pid

    Yes, the differences between AX-18 and MX-28 are:
    - higher-resolution encoder in MX-28
    - stronger motor in MX-28
    - higher operating voltage in MX-28
    - faster embedded control CPU inside MX-28
    -...
  38. Replies
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    MX-64 bricked after update

    So, I have this problem where I have some MX-64 servos running firmware version 33 (pretty old.)
    I've tried updating them with Dynamixel Wizard 1.0, but that update reports "failure" and then the...
  39. Thread: Malum IK

    by jwatte
    Replies
    55
    Views
    5,542

    Re: Malum IK

    I'm in discussion with Robotis tech support about the servos that died when trying to update them.

    A few things I really need to do, based on learnings:

    1) A gun feeder that doesn't jam. I have...
  40. Thread: Immortal (V2)

    by jwatte
    Replies
    18
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    2,395

    Re: Immortal (V2)

    Love the Exorcist head spinning :-)
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