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Nice Lynx Motion Arm — Parallax Forums

Nice Lynx Motion Arm

ercoerco Posts: 20,194
edited 2022-04-13 19:00 in Robotics

Beauty is only skin deep, but Lynxmotion's 6th-gen arm looks pretty sexy IMO! External black/white shells really jazz it up, even if the carbon fiber pattern is likely just for show. Too bad the sizzle video (bottom) doesn't show it in motion. http://www.lynxmotion.com/c-194-lss-arms.aspx

Comments

  • MicksterMickster Posts: 2,216

    Skin deep is right. They don't show it moving because then it becomes Ricketymotion :lol:

    Parallax need to hook-up with
    https://www.anninrobotics.com/

    Get the P2 involved and closed loop servos... Demonstrate that the P2 is the ultimate single-chip robot controller and educate students about real robotics :smile:

    Craig

  • Many years ago, I purchased a Lynxmotion SmartArm. It used Dynamixel servos. I think my version has a single servo for the claw but otherwise it looks a lot like the one in the photo below.

    The Dynamixel servos use a communication protocol which required a microcontroller to be present between the user inputs and the servos. The servos in this new arm use the Lynxmotion Smart Servo (LSS) serial protocol. The LSS protocol is "human readable" in that it uses only the printable ASCII characters but comes at the cost of slower data exchanges. The LSS protocol also doesn't use CRC or a checksum. I personally think the Dynamixel protocol is a better than the LSS protocol in this sort of application.

    @erco said:
    External black/white shells really jazz it up, even if the carbon fiber pattern is likely just for show.

    I'd think it shouldn't be too hard to 3D print similar panels for other robot arms. I'm tempted to dig my SmartArm out and see if I can make it look better by adding some panels.

  • MicksterMickster Posts: 2,216

    @"Duane Degn"

    With all respect...still rickety bullshit.

    The P2 deserves some serious exposure. It represents a huge commitment on the part of Parallax. Who's gonna take it seriously when all we show is herky jerky Smile?

    Robots are nothing like this 👎

  • ercoerco Posts: 20,194

    @Mickster: You make some bold statements there, we can't wait to see what you come up with. Please keep us advised of your progress.

  • Parallax need to hook-up with
    https://www.anninrobotics.com/

    Wow! That AR4 robot totally nailed Erco's Figure Eight ChallengeTM! (starting at 2:35)

    -Phil

  • MicksterMickster Posts: 2,216

    Oh I am committed to promoting this awesome device that is P2

    Arduino has Portenta...are you kidding me???
    It's a damn joke!!!

    We need to get Parallax out of hobby world!!

    Look at the LM629
    Look at the HCTL1100

    Feeble, single axis

    Can you say lame? Look at the price.

    As I stated many times; Parallax has unwittingly created the most powerful motion control processor ever.

    Motion is a huge and growing industry.

    P2 needs to be in the big leagues.

    I'm doing my bit :+1:

  • ercoerco Posts: 20,194

    @"Phil Pilgrim (PhiPi)" said:

    Parallax need to hook-up with
    https://www.anninrobotics.com/

    Wow! That AR4 robot totally nailed Erco's Figure Eight ChallengeTM! (starting at 2:35)

    -Phil

    Amen Br'er Phil! Martin_H also had an arm that drew an 8 in the challenge!

  • @Mickster said:
    As I stated many times; Parallax has unwittingly created the most powerful motion control processor ever.

    What sort of hardware do I need to take advantage of the P2's motion control abilities?

    Is the Universal Motor Driver Addon a good place to start with controlling brushless motors?

    The robot arms shown early are hardly rickety, at least they're not rickety compared to one of my early robots. He's a rickety robot:

    @Mickster said:
    Who's gonna take it seriously when all we show is herky jerky Smile?
    Robots are nothing like this 👎

    Then let me try again.

    Seriously, I am working on a "real" P2 project. I'm working an industrial flow meter project which uses the P2 to read sensor data and display appropriate values. The P2 based flow meter will be built to industrial quality standards but for now, my robots will likely remain relatively rickety.

  • ercoerco Posts: 20,194

    Duane, I gotta see more popsicle stick robots! In fact, I suggest you start a new thread on them, the Popsicle Stick Robot Challenge, akin to the Figure 8 Challenge (F8C). I'll make some! I say leave it purposely loose like F8C to avoid restrictions... using popsicle sticks, tongue depressors, soda straws, chop sticks, paint stir sticks... maybe any cheap or disposable item.

    That way, new builders can show off their robots in both challenges. Win-Win!

  • MicksterMickster Posts: 2,216

    @"Duane Degn" said:

    @Mickster said:
    As I stated many times; Parallax has unwittingly created the most powerful motion control processor ever.

    What sort of hardware do I need to take advantage of the P2's motion control abilities?

    Next to nothing:

    • A MC3486 line-receiver for the differential encoder signals. 5v so I need to level-shift but this DIP device is in plentiful supply
    • An op-amp to produce a +/- 10v motor-command signal from anti-phase PWM

    Right there, I have a Galil-compatible axis interface. Add another line-receiver and I have dual-loop capability (same as the Galil)

    With this, I can directly drive:

    Is the Universal Motor Driver Addon a good place to start with controlling brushless motors?

    Absolutely!....Parallax already has all the required ingredients :+1:

    However, I would like to eventually incorporate a P2 in a range of more powerful drives, such as:
    https://www.st.com/en/evaluation-tools/steval-ihm028v2.html#design-scroll

    Craig

  • MicksterMickster Posts: 2,216
    edited 2022-04-16 03:54

    @"Phil Pilgrim (PhiPi)" said:

    Parallax need to hook-up with
    https://www.anninrobotics.com/

    Wow! That AR4 robot totally nailed Erco's Figure Eight ChallengeTM! (starting at 2:35)

    -Phil

    Evidently doesn't have constant vector velocity though and I doubt that he ever will, with that controls package.
    The Annin Robot ship is missing a Propeller :smile:

    Furthermore, he only shows picking-up loose objects. When it comes to placing/removing a workpiece in a lathe-chuck or a machining-center vise, he'll need to relax those joints to let the arm comply. AFAIK, this is not possible with stepper-motors. With torque-commanded servo motors, this is achieved via torque limiting or, more-crudely, reducing the PID filter gains.

    Craig

  • Mickster,

    Are there any kind of mid priced robotic arms that use servo control? Say, a $2K desktop arm that uses optical encoders and common (but strong) gear motors

    Kinda getting tired of seeing people try to make stuff like this with stepper motors. (and even worse, hobby servos)

    I wonder how feasible it is, to get a reasonable performance 3D arm using common gear motors without harmonic drives. I don't think there is anything like this out there. And the reason may be that it isn't possible. With your expertise, wondering if you have any thought on this

  • MicksterMickster Posts: 2,216

    @The_Master said:
    Mickster,

    Are there any kind of mid priced robotic arms that use servo control? Say, a $2K desktop arm that uses optical encoders and common (but strong) gear motors

    Kinda getting tired of seeing people try to make stuff like this with stepper motors. (and even worse, hobby servos)

    I wonder how feasible it is, to get a reasonable performance 3D arm using common gear motors without harmonic drives. I don't think there is anything like this out there. And the reason may be that it isn't possible. With your expertise, wondering if you have any thought on this

    None that I know of but it appears that Jeremy Fielding is part-way there:

    https://youtu.be/AMxDmjyL8rg

    I haven't followed all of his videos so I don't know about cost but at least he has used servo-motors. It looks like he has taken Annin's design and scaled-it-up. However, as can be seen in the video, he's running in to control problems (Annin's controller).

    Another approach, although maybe bigger than what you are looking for, is a brain-dead industrial robot. They can be picked-up for scrap-value, it's amazing what companies throw away. I have one here, it's a welding robot, complete with enclosure. The only real cost was transport. Not sure if this will get the P2 treatment yet but it certainly won't be having the original control repaired because then we're talking serious $$$. I am more interested in material handling but this thing might be good for a start.

    Craig

  • MicksterMickster Posts: 2,216

    @The_Master

    I wonder how feasible it is, to get a reasonable performance 3D arm using common gear motors without harmonic drives.

    Heck, I just did a search on Alibaba.com for Harmonic Drive and some really nice stuff comes up. I just wonder how real those prices are.

    Craig

  • ATTENTION Lynxmotion, et al:

    10 W motor per limb, no harmonic drives:

    Get to work. There is no longer need for anyone to doll up hobby arms with plastic shells

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