Robotics

Discussion in 'General Science' started by Wendy, Oct 9, 2011.

  1. Wendy

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    I've started other threads on general subject, to give myself and others a place to put interesting stories that don't lend themselves to discussion.

    Boston Dynamics has come up with some interesting stuff, like the two legged walker that is eerie how much it resembles the bottom half of a human.

    They've just released footage of Alpha Dog, a 4 legged walker. Power supply is still an issue, but again, this looks like an animal, not a robot.

    Boston Dynamics unwraps military robot AlphaDog (w/ video)
     
  2. bertus

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  3. Wendy

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    We've had several threads about them in the past, my starter was the latest.
     
  4. Georacer

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    BigDog is out some time now, I knew about it since last year. All of the Leg Lab videos make me drool.

    AlphaDog seems to be its latest version, which I didn't know about. They seem to have solved the issue of the gas motor noise - or not. Notice that this model is wired to its frame. It's always fun to watch it get pushed around, though.
    Thanks for the video Bill.

    I had bought the Lego Mindstorms myself when I was in highschool and built an autonomous wheeled room explorer with collision avoidance. Other things got my interest later, unfortunately. I hope to play with Mindstorms some more one day.

    For now, my take on robotics is a CNC router I 've just started building some days ago. I 'm cutting the MDF frame right now.
     
  5. BMorse

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    Robotics has definitely come a long way, I am really partial to the Asimo robots.... and these little guys >>>http://youtu.be/rokOtmUhos0

    My next few "robotics" projects have to do with CNC's also, I am currently designing my own digitizer probe for my CNC PCB Mill/Drill, so I could "trace" parts into the CNC software, another project in the works is converting a 3 axis vertical Mill into a 3 Axis vertical CNC Mill.... working on getting motors and controllers sorted out right now for that... and also I will be working on adding another Axis to my CNC Mill, so I will have a 4 axis CNC PCB Mill :)
     
  6. shortbus

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    @BMorse, what CNC software do you use to drive the mill?
     
  7. BMorse

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    Right now I am using KCAM4 by Kellyware (which can control up to 4 axis'), but will be switching to either EMC2 or MACH3 in the near future to be able to do tracing with my digitizer...


    for reference, here is a good listing of different software available for DIY CNC machines http://www.probotix.com/cnc_software/..... EMC2 is completely open source, and the most flexible to use on any machine.....
     
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  8. Georacer

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    BMorse, if memory serves me right, you owned a couple of CNCs, right? Did you build them yourself?

    Any piece of advice that I should keep in mind, since I 'm a novice in this kind of build?
     
  9. BMorse

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    Yes, I do own a couple of CNC's I built myself, this is the current one I use for my PCB's and general engraving at home >> http://www.morse-code.com/id18.htm.....

    The most important thing I guess would be to pick the best motors to start with.... I spent years trying to use salvaged steppers out of industrial copiers and printers, but could not get any of them to work decent enough for a CNC mill, they were all pretty slow and low torque.... I currently use 3 NEMA 23 80oz Bi-polar Steppers that I salvaged out of some recycling machines.... That is one problem I have noticed with everyone else trying to build a home made CNC machine.... another is building the controllers, you can either purchase some prebuilt ones, or design them yourself, I opted for the latter, since I do not have a budget for my projects.... some companies would give out samples of Stepper controllers if requested, but most won't do that now since some people have ruined it by getting samples and reselling them on Ebay....
     
    Last edited: Oct 9, 2011
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  10. Georacer

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    Your project looks neat, but unfortunately I don't have access to a metal workshop and I know zilch about building with metal.
    So for now it's wood for me. I have doubts about its stability but I guess I 'll find out if it suits me or not.

    My electric jigsaw is cutting a bit sideways too, an added source of frustration for me.
     
  11. BMorse

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    Wood could be used, but just keep in mind that wood can flex or get warped out of shape with differences in humidity, and temperature...... but if you use plywood, and laminate several pieces together from thinner stock, you may be able to overcome the probability of it warping from temp and humidity.......
     
  12. shortbus

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  13. Georacer

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  14. Wendy

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  15. strantor

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    I came across the bigdog a year or two ago and was watching all the videos of it on youtube and came across this. you really must watch a few bigdog videos before you click on it, to get the full effect.
     
  16. Wendy

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    Bigdog is obsolete, replaced by Alphadog, which is referenced in post #1. They also had the human version of Bigdog underway at the time. We had several older posts back when, and I decided to make this thread for interesting stories along these lines.
     
  17. strantor

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    Yeah, I got that, and I saw the petman video, but the video I linked to is still worth a watch :) hint hint
     
  18. Wendy

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    Post em or refer to the old threads, that is what this is for. I saw an interesting article in physorg.com about spider bots I need to look up again.
     
  19. thatoneguy

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    What do you use for leadscrews and nut?

    The ball nuts I've looked at for zero backlash and great tolerance seem to cost more than the steppers, and stepper control board if you count the carriage rod for the ball screws on 3 axis.

    I'm still unsure if buying a 3 axis mill with ball screws and solid work area already set up, then converting it to CNC would be a better alternative than building one from scratch, for "best accuracy per dollar spent".
     
  20. Wendy

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