Search:

Type: Posts; User: tician; Keyword(s):

Page 1 of 13 1 2 3 4

Search: Search took 0.03 seconds.

  1. Replies
    8
    Views
    338

    Re: Questions about powering

    03-25-2020


    Keep the voltage at or below 12V.

    Never stall the motors ('continuous' torque of the servos is at most ~1/3 of stall torque).

    Never let any joints be driven into interference...
  2. Question(s) Re: Attempting to make simple script to move the motor to angles between 0 and 360

    argh. again? That library/example does not indicate what version of the SDK it is designed around or which one you are using. Older SDK versions do not necessarily support the DXL2.0 protocol or...
  3. Question(s) Re: Attempting to make simple script to move the motor to angles between 0 and 360

    The PROTOCOL_VERSION must be set to 2.0.
    The BAUDRATE must match the setting shown in Dynamixel Wizard.
    The MAX_POS_VAL = 1023 must be changed to MAX_POS_VAL = 4095.

    I did not look closely...
  4. Replies
    4
    Views
    297

    Question(s) Re: Connecting Dynamixel Motor to PC (Windows)

    yep. Only one program can access a given port at any one time.

    The Windows serial port (COM) interface is particularly annoying in that it operates on the absolute assumption that a port cannot...
  5. Re: Planning to build HR-OS1 robot using AX-12A & AX-18A (looking for frames)

    If you are feeling adventurous, it might also be worthwhile to go with the newer XL430 servos (https://www.trossenrobotics.com/dynamixel-xl430-w250-t.aspx)...
  6. Re: Planning to build HR-OS1 robot using AX-12A & AX-18A (looking for frames)

    What sort of software are you planning to use?

    The Bioloid Premium kit is built around Robotis' CM-530 controller which is not compatible with the DARwIn-OP/HROS-1 framework and gait engine. It...
  7. Re: Planning to build HR-OS1 robot using AX-12A & AX-18A (looking for frames)

    I'm not aware of what happened internally at Trossen, but I've not seen much of several of their long-time employees and their development platforms have shifted almost exclusively to ROS and robot...
  8. Replies
    4
    Views
    297

    Question(s) Re: Connecting Dynamixel Motor to PC (Windows)

    Which versions of Dynamixel Wizard and the DXL SDK are you using? The X-series servos all use DXL2.0 protocol, which is different from DXL1.0 protocol.

    RoboPlus was broken into separate downloads...
  9. Re: [Beginner here with no experience] Need help with Ideas for implementing an automation process

    Just a little clarification: a fastener is tightened to a specified torque to exert a desired clamping force. There are a number of parameters that must be examined to correctly select a fastener...
  10. Re: [Beginner here with no experience] Need help with Ideas for implementing an automation process

    I'm inclined to suggest a guillotine for the penny-pinching executives whose bonuses cost more than flat out replacing all the fasteners during every aircraft airframe/engine overhaul. Barely costs a...
  11. Re: [Beginner here with no experience] Need help with Ideas for implementing an automation process

    Are these fasteners being used in any sort of life/limb threatening situation? DO NOT REUSE THEM! EVER!

    The highest strength alloy steel bolts can be reused in some situations where they have not...
  12. Re: [Beginner here with no experience] Need help with Ideas for implementing an automation process

    Lots of options.

    Easiest that comes to mind is a hopper holding the unsorted parts that are fed onto a conveyor belt in a well spaced manner (one fastener on the belt every couple inches). The...
  13. Thread: Which one?

    by tician
    Replies
    1
    Views
    180

    Re: Which one?

    Considering a standard humanoid robot would have two arms, is it not obvious?

    Anything more complex than a toy humanoid robot using hobby servos or AX-12 dynamixel servos is going to be a very...
  14. Question(s) Re: What is the best way to remove the horn of the Dynamixel?

    I only add the center screw to make it easier/safer to pull the horn off the spline (just tighten the screw and it gently pulls the horn off without any force on the bearings in the front case). ...
  15. Question(s) Re: What is the best way to remove the horn of the Dynamixel?

    I do not know how it could damage the motor. Improper methods can destroy the threads in the output gear/spline, or break the spline off the output gear, or crack the front face panel of the servo...
  16. Question(s) Re: What is the best way to remove the horn of the Dynamixel?

    That video is infuriating. Pulling the center screw out like that before pushing on it with the bearing puller can destroy the threads in the output gear/spline.

    You do not need a bearing puller....
  17. Question(s) Re: What is the best way to remove the horn of the Dynamixel?

    For the MX-series, I used a spare horn to remove them, but a piece of aluminum ~3mm or thicker with a few holes drilled (and one tapped) would work just as well. The plate needs a center hole tapped...
  18. Replies
    3
    Views
    1,055

    Re: Robot Body Shell

    I'm a fan of the rutan 'cast/carve foam into shape then coat with fiberglass+resin' construction method, but not used it for robots yet. The resulting composite is very stiff and lightweight (good...
  19. Thread: mjbots quad A0

    by tician
    Replies
    25
    Views
    5,825

    Re: mjbots quad A0

    Not quite what I was thinking of...

    Cannot get image upload as attachment to work right now and getting a mysql error trying to access settings to add an image, but it is literally a U-bracket...
  20. Thread: mjbots quad A0

    by tician
    Replies
    25
    Views
    5,825

    Re: mjbots quad A0

    Any thoughts on combining two of the servos onto a differential similar to this to make the two-axis joints a bit more compact/robust? I'm thinking more or less a U-shaped bracket with a hard-mount...
  21. Re: Should we move Mech Warfare discussions to some other forum?

    Never touched discord before...

    Hoping that quarantine will make me build stuff instead of continuing to sit on my ass, but not too hopeful. Debating whether to pay >$150 in shipping or make a...
  22. Re: Should we move Mech Warfare discussions to some other forum?

    Really hope the forums live on, at least as a reference/archive... Haven't bought anything recently, but could make a direct donation to keep them online.

    ...now made a hackaday.io account just in...
  23. Question(s) Re: Can we get accurate torque and current information from the dynamixels now?

    "A low-cost compliant 7-DOF robotic manipulator" (pdf here)
    Involves two disks linked with rubber tube stuck in cutouts in the disks to make compliant linkages (flex couplings) that allow fairly...
  24. Question(s) Re: Can we get accurate torque and current information from the dynamixels now?

    I have not used Robotis stuff in a few years, but I specifically recall the MX-28 having neither current-limiting motor drivers nor current sensors. It had only a magnetic encoder and an H-bridge...
  25. Thread: Malum IK

    by tician
    Replies
    69
    Views
    19,433

    Re: Malum IK

    I was never able to access jwatte's and mine is no longer showing the thumbnail or even properly linking the image. Might be because of "invalid token"/timeout -> re-open in new tab -> restore...
  26. Thread: Malum IK

    by tician
    Replies
    69
    Views
    19,433

    Re: Malum IK

    More crammed than this 33x50mm thing?

    7640

    ATSAM D21 for control with 32k crystal, primary TB67S249 stepper driver, secondary DRV8871 brushed DC driver (for solenoid-based shutter), two...
  27. Thread: Malum IK

    by tician
    Replies
    69
    Views
    19,433

    Re: Malum IK

    Robotis ran into dead IC problems when using a single two-channel buffer on their earliest CM-900 boards, so they switched to two one-channel buffers at different voltages (5V TX to buss; 3.3V RX to...
  28. Replies
    4
    Views
    1,872

    Question(s) Re: Arduino 1.8.10 ?

    The board manager definitions from this thread will probably still work......
  29. Re: Question about a particular omnidirectional robot design

    Pretty much anytime I hear omnidirectional, it is some sort of omni-wheel or mecanum wheel system (even 3 or 4 omni-wheels balancing on a large ball for single ground contact point). Suppose the...
  30. Re: Question about a particular omnidirectional robot design

    I've usually seen that design referred to as some variant/combination of "steered/steerable/powered caster". The willowgarage pr2 was one of the better known designs using it, so that is another...
  31. Replies
    278
    Views
    108,991

    Project Re: More Mule then Rover?

    Just needs a new boot on the spark plug connector... and might be a bit under-powered for that alternator at full load. 1[hp] is 746[W], so even 100% conversion efficiency won't give you full 24V...
  32. Replies
    10
    Views
    3,518

    Re: Novel leg/chassis design

    For linkage based walking robots, see also: https://www.youtube.com/user/psyclopz http://www.nidona.com/marauder.html
  33. Replies
    10
    Views
    3,518

    Re: Novel leg/chassis design

    Which is the undecided factor that goes in the square tube cutout in the actuated end of the linkages. My first thought for that was solenoid, then linear actuator (threaded rod coupled to a small...
  34. Replies
    6
    Views
    2,229

    Re: Power for eight (8) Dynamixel XM-430-W350-R

    batteryspace.com still sells plenty of LiFePO4 cells, and assorted e-bike sites sell them as well.

    The 'accurate positioning on a plane' bit says indoor with human interaction not outdoor speed...
  35. Replies
    6
    Views
    2,229

    Re: Power for eight (8) Dynamixel XM-430-W350-R

    bleh. I've been encountering lots of people not reading for comprehension recently... one in particular at work last week.

    jwatte, they mentioned in the very first sentences: four independently...
  36. Question(s) Re: U2D2 Power Hub and LIPO Battery 11.1V 1800mAh LB-012

    The problem is that battery uses a Deans / T-connector and the board does not have that anywhere on it. So, you need something like this (https://www.trossenrobotics.com/battery-wiring-harness) or...
  37. Replies
    4
    Views
    3,589

    Re: The Raspberry pi 4 Model B

    In theory, the RPi4+4GB is more powerful than my netbook in its default configuration (2-core 1.0GHz/1.33GHz, 4GB, USB2, Fast Ethernet, 802.11n)...

    Probably will pick up one of the RPi4+4GB in the...
  38. Thread: Rip Van Winkle

    by tician
    Replies
    5
    Views
    2,726

    Re: Rip Van Winkle

    I almost posted before about this in one of the Malum IK threads, but that ODrive board brings the ick back to the surface...
    if you are not using BGA ICs with sensitive power requirements and/or ...
  39. Thread: Malum IK

    by tician
    Replies
    69
    Views
    19,433

    Re: Malum IK

    How has your experience with MacroFab been? Spent an hour or so assembling some PCBs* for small scale production (Seeedstudio PCBs and stencils plus low-temp solder paste), but hand producing these...
  40. Replies
    4
    Views
    2,825

    Question(s) Re: AVRDUDE ERROR - arbotix board

    It is possible - although not probable - that the FTDI dongle you are using is not plugged into the arbotix correctly, or it is unable to provide enough power to the arbotix. Are the jumpers set...
Results 1 to 40 of 500
Page 1 of 13 1 2 3 4