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Thread: Immortal (V2)

  1. #1
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    Immortal (V2)

    I have been working on a new mech for about a month now, I just recently decided that I would name it the same as its predecessor - Immortal. Since I have a name I figured I should make a post to share what I have been working on. Its predecessor Immortal (V1) was originally a 16dof AX-12 based quad modeled very roughly after the Starcraft unit, the Immortal. Over several years of service I had done many changes to address the shortfalls of the design - such as turning it into a 8dof quad to reduce stress on the servos and upgrading the camera to 5ghz. A number of things were not feasible to update in the original design though. Here is the short list of the things I want to implement from 7 years of starting new designs and never following through.

    More reliable gun(s)
    continuous rotation turret
    camera is always forward mode
    higher precision turret control
    Auto tracking targeting
    Super fast
    RX-24/28 based
    Look really cool

    Every time I have started working on a new design I always got stuck at the first item, more reliable guns. Thanks to Don for sending me his design which I used as a basis to design something that is reliable and small form factor. This is what the design looks like:




    To be continued...

  2. #2
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    Re: Immortal (V2)

    Quote Originally Posted by cire View Post
    Look really cool
    If I recall correctly, Immortal had this design feature fairly well developed. I look forward to seeing want innovations can be made in that area.

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    Re: Immortal (V2)

    Quote Originally Posted by byi View Post
    If I recall correctly, Immortal had this design feature fairly well developed. I look forward to seeing want innovations can be made in that area.
    Well, one could argue that all mech warfare robots look cool! I was quite happy with the end result of the original, especially the legs before I switched to 2DOF, the turret never quite matched the base though. I plan to do something with a little more detail this time, which has been my main focus for the last couple of days, updating the above design into something more unique.

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    Re: Immortal (V2)

    Here is a test walk for the platform I am building the new Immortal on. It walks fairly smoothly, although the feet would slip a bit on the flooring I was using. All of the parts are 3d printed. I use RX24F's in the joints that rotate the body so they can move very fast. It uses RX28s to lift the feet. It runs pretty cool due to the kinematic layout, although I most likely won't run it at its max speed in competition because RX24F servos are in general prone to overheating.


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    Re: Immortal (V2)

    Very nice

  6. #6

    Re: Immortal (V2)

    Nice! I think the slip actually helps, because you don't have 3DOF legs, so you "scoot" with some slide.

    Also, my experience with Onyx was that the servos could turn the body much faster than I could reasonably react/control through the video, so I actually turned down the sensitivity. The thing that drives turning speed the most is how centrally you can locate the hip/turn servos, more than the speed of those servos.

    Anyway, looks great! Put a gun on it and jump in :-)

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    Re: Immortal (V2)

    I have been pretty far behind on posting my progress. I already had the turret on when I made the first post, so this post is meant to catch up.

    I have the turret installed and working - 0% missfires after a few hundred shots, a new small 5ghz camera, color based vision tracking, and a turret is always facing forward piece of code.



    The robot performs quite nicely in this state, however the turret control wasn't exactly the best so I was considering redesigning the turret to use a gimbal. After a few days of research, I realized I was going to need to redesign the turret to do what I really wanted to do, so I thought I would use it as an opportunity to redesign the entire aesthetics. It was at this point I decided to go visit the original Aesthetic of Immortal - and give it the same name. I figured I could make it look a lot more Immortal-like now that I have access to a 3d printer that was good enough quality that I could actually print some cool looking pieces with it.

    I found a model that an artist made (Renders here https://www.artstation.com/artwork/v10Vm3 ), and asked them if they would send me their model so I could turn it into a robot. They were happy to share it with me, and so the "lots of extra work for negative performance gain" began.



    A few compromises had to be made to fit everything into the model. First of all I couldn't find a good place for the target panels, so I ended up spreading the legs out of proportion which made it easier to fit the electronics and battery in the base as well. The tilt no longer has a linkage and is directly mounted on a mx28 servo, rather then a rx28 servo which I hope helps keep the accuracy about the same - the guns themselves are fairly balanced so I hope the servo does not work too hard to maintain its positioning. The overall robot is much heavier then the bare bones robot I built originally, and it has horrible heat dissipation properties due to everything being mostly enclosed in plastic with little infill - I will do some testing with the RX24F servos, and might need to switch to RX28 if they get too hot.

    I didn't want to deal with wires from the base to the turret, so I added a second controller and battery in the turret and plan to send the turret angle to the base from the turret so the base knows which direction to walk. This disconnect between the top and bottom should allow me to do 360 rotation of the turret if I can figure out a way to do it with the mx-28 servo while maintaining the precision.

    Probably the weirdest thing about the design is going from single gun back to two guns. The guns are now very far from the camera and it is going to make doing accurate vision tracking harder. The original Immortals guns were fairly close to each other which allowed for a pretty good crossover point, but with this design it they are quite wide so usually only one gun will be able to hit the target at a time. It never hurts to have a second gun for reliability though. I considered not putting anything in one side, but figured I would have balancing problems if I did that since the guns mass is pretty off center.

    Here is a working gun, one of the first pieces printed, although I need to reprint the hopper (top piece) because it warped. Lots of work remaining...

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    Re: Immortal (V2)

    Very cool!

  9. #9

    Re: Immortal (V2)

    so the "lots of extra work for negative performance gain" began
    Spoken like a true hero! This looks awesome.

    Some suggestions that may or may not help:

    https://www.digikey.com/product-deta...386-ND/7606171 -- plug straight into Dynamixel power bus and fit between the brackets (20mm square)

    https://www.digikey.com/product-deta...106-ND/1165500 -- less space and lower CFM, but still helpful and quieter; require 3.3V conversion

    Balancing the guns on a "tipping" MX servo worked fine for Onyx; as long as the COG is close to the axis of rotation, the torque needed is quite low.

    If you don't need 360 rotation, then routing flexible silicone wire with sufficient slack loops worked fine for me. You could print a shroud around the axis if you want to hide it? Or there are these: https://www.sparkfun.com/products/13063

    Whatever you do, I love seeing this build progress!

  10. #10
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    Re: Immortal (V2)

    Holy cow that thing is speedy!

    I will have to take my next gait iteration up a notch or start putting serious thought into that jump jet idea if I plan to keep up with the mobility improvements lately (as if my builds had been keeping pace in the first place (-: ). Or just finally upgrade from AX servos...
    Last edited by byi; 2 Weeks Ago at 02:04 PM.

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