New Parallax 360 Feedback Servo

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Comments

  • 25 oz.-in. isn't too shabby for such a small motor -- especially one that's geared for high speed! And with a higher Vin, one should expect to get even higher values.

    -Phil

    So about 170 mNm for those who use SI units :-)
  • What's the convertion rate to carat-furlongs?
    "When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."

    - Pablo Picasso
  • tomcrawfordtomcrawford Posts: 723
    edited October 9 Vote Up0Vote Down
    Here, I hope, is a video of driving four feedback servos from a single PASM cog.

    Each servo is commanded to a new (random) position as soon as it completes the current move.
    Re-inventing the wheel is not a waste of time if, when you are done, you understand why it is round.
    Cool, CA, USA 95614
  • Looks good here Tom.
    Infernal Machine
  • Great job, Tom. Cog it up!
    "When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."

    - Pablo Picasso
  • erco wrote: »
    What's the convertion rate to carat-furlongs?

    No idea; who uses carat-furlongs?

    SI units are the international standard, and apart from a few hold-outs are used world-wide.
  • AJL

    It's complicated...

    A furlong is 40 rods... and a carat is 0.2gm.

    So, the conversion is quite straight forward.

    In England, asking for a conversion to carat-furlongs is the same as saying that something is worth its length in diamonds/// except in nautical references, in which case carat-leagues refers to depth in pearls.

    In this context, I think it would have been suffice to say that these little contraptions are worth their weight in gold.

    Why erco didn't just say this is beyond me.

    BAD ERCO!!!








  • erco wrote: »
    What's the convertion rate to carat-furlongs?

    Google has thought to include Velocity conversions to furlongs / fortnight, (eg 5 mph = 13440 fpf), but it seems they did not think to extend that to carat-furlongs ;)
  • ercoerco Posts: 18,414
    edited October 10 Vote Up0Vote Down
    Simple math, lads. Per Phil, this servo has 25 ounce-inches of torque.

    Multiply by 141.7 carats per ounce. Divide by 7920 inches per furlong.

    Thus, this servo has 0.447 carat-furlongs of torque. Good to know!

    rjo__ wrote: »
    AJL

    It's complicated...

    In this context, I think it would have been suffice to say that these little contraptions are worth their weight in gold.


    Here we go again, getting set up for more confusion!

    The servo torque rating uses a standard ounce=28.4g

    But gold is weighed using the Troy scale, 1 Troy ounce=31.1g

    So a Troy ounce weighs almost 10% more than a standard ounce.
    But a Troy pound has only 12 Troy ounces, equal to 373.2g
    So a pound of gold weighs 18% less than a standard pound.

    https://www.jmbullion.com/investing-guide/types-physical-metals/troy-oz/

    We all good?

    "When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."

    - Pablo Picasso
  • Erco,
    Anytime you want to send me a pound of gold, I will gladly pay the shipping!
    Jim
  • I'm on it like a rash, RS_Jim!

    I puzzled the twins today with the classic question, which weighs more, a pound of gold or a pound of feathers...?
    "When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."

    - Pablo Picasso
  • I prefer my torque measurements in parsecs. To get you started, one foot is equal to 9.8779E-18 parsecs. You can use it to better determine how long it will take your robot to do the Kessel Run. (Just remember not to make the same mistake about parsecs as Han Solo did.)
  • Thanks Gordon. Before I try parsecs, I need to locate a weightless 1-furlong beam to check my carat calcs.

    So far, Ebay Chna is failing me.

    "When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."

    - Pablo Picasso
  • erco wrote: »
    So far, Ebay Chna is failing me.

    Which you'd expect, as Chna is the southern forest region of Endor. Don't you know anything?!

    (Okay, so I saw the latest Star Wars trailer.)

  • Say what you will, good ol' Prop does honk! 5000 microseconds is a long time.
    1700 x 2338 - 2M
    Re-inventing the wheel is not a waste of time if, when you are done, you understand why it is round.
    Cool, CA, USA 95614
  • Whatever you do, don't install this program:

    https://www.gnu.org/software/units/units.html
    $ units
    Currency exchange rates from www.timegenie.com on 2017-03-08
    2980 units, 109 prefixes, 96 nonlinear units
    
    You have: 25 oz*in
    You want: carat*furlongs
            * 0.44743566
            / 2.2349582
    You have: c
    You want: furlongs/picofortnight
            * 1.8026175
            / 0.55474886
    You have: barn*megaparsec
    You want: tsp
            * 0.62603503
            / 1.5973547
    You have: barn
    You want:
            Definition: 1e-28 m^2 = 1e-28 m^2
    
  • Here is my version of a spin driver for the fancy new FeedBack Servo.

    It provides control for up to four servos in a single cog. It provides methods Set Position, Check Set Complete, Get Position, Set Fixed Pulse Width, and Set Parameters.

    Set Position gets within +- 1 degree of the commanded position.
    Re-inventing the wheel is not a waste of time if, when you are done, you understand why it is round.
    Cool, CA, USA 95614
  • Thank You Mister Servo! :)
    Infernal Machine
  • WhitWhit Posts: 3,706
    edited October 19 Vote Up0Vote Down
    erco wrote: »
    I need to locate a weightless 1-furlong beam to check my carat calcs.

    So far, Ebay Chna is failing me.

    I was going to try to find you one, but I realized you would post right back with a lower price...

    Great info in this thread you all! Other projects have kept my 360 degree servos on the bench... Plenty of other robotic fun in Louisiana though!

    Whit+

    "We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney
  • Phil:

    I had to open one too, it's just in my nature to know how something works.Device on a Wire
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