well I’m looking to build a hexapod with a rotating tray on top… well lets face it not a tray a turret. it only needs to rotate about 180 degrees but that needs to sit atop the legs. and since though this has been a long time dream of mine it is only now accessible. So i have no idea where to get the parts, what parts to get, i don’t even know how to program it yet
but heres what i know. i can do it, i can learn it and, it will be done. I also know that to control it i want 2 usb joysticks(one for controlling the direction of the movement of the legs, and one to control the swivel of the turret and maybe even angeling the frame forward nose down back nose up) a forward back shifting knob to change the gait and then 2 pedals to control the accel/decel all this while running a script to keep it balanced and auto adjust for terrain if necessary and also say on this turret there were 4 moving cameras that needed to point in the same spot and follow the cursor. and i don’t know anything about code or programming so that could be impossible or it could be simple i don’t know.
keep in mind all this will be running of its own desktop comp so i figured that would be sufficient. BUT! i don’t know how to write code read code where to put code into what programs. and thats why im asking you.
all these controllers for this little bot? its something to help me write the programs and build a test model so i can build one i can ride around in and shoot paint balls at trees with! can you help me?
Welcome to this great forum!
I like your ambitious project. If you have any drawings you could post them in the project section.
Have you considered one of Lynxmotions hexapods for this project, like the AH3-R:
With sensors on the feet, compatible with the AH3-R:
I think Laurent is working with a powerpod for foot sensors? Or am I wrong.
FYI, there are mounting holes for the turret already on the round hexapod’s chassis. 8) As far as the hardware we have everything you need to do what you want. The control aspect will take a little work, but there is a lot of information at the website or the forum.
Hmmm, if you’re planning on riding on it, then you’re definitely not going to be able to use servos, at least not with these hobby servos. If you want to play with it without riding on it, I agree with A-Bot and all the others:
don’t forget the servo for the base rotate kit:
And whatever else you would like to add to the base rotate kit, perhaps claws or arms?
Oh by the way, you haven’t even begun building the robot, you’re not crazy… yet…
I thought about making a larger CH3-R also, of course this would be a long road down the future. If I had a CH3-R that can carry a payload of say 250lb nominal, it’d be neat…
That youtube.com video is way wicked! I want one of those…
yeah one of the things i didn’t mention was that yes when i build the full size one im going to switch out to hydraulics which will more than likely be different to program(is this true?) and the redneck spider mech looks liek it runs of a turning shaft which is why it is built that way so mine will look a bit more like the electrical ones you fine people build! just imagine six backhoe arms as the legs and thats pretty much the hookup. but i guess my four main questions are 1) how do I program? 2) how do i run the program? 3) will it be helpful to build the smaller electrical one if the programming will be different for the hydraulics(if it is different)? 4) any other good sites for research and assistance? although so far this seems like a one stop shop!
and i guess im also asking if anyone can help me build and understand a base program that i can then tweak and fine tune into an operable and final system.
and as far as general questions go, lets say i build the final one and i set the gait for 3 legs to move at once (3rd motion type ill program in) is there a way to accelerate that or will there pretty much be one speed to each gait?
As JackStickely mentioned we’ll be using hydraulics for the legs (similar to… or even backhoe arms[yes this is planned to be big]). Where some of the troubles come in are not necessarily design of it… but figuring how to get our ideas to come to life.
The one thing that we cannot do ourselves is making a program do what we want…
The plan is to have a PC as the brain (more than likely running Linux), running a pc as the brain of the whole thing will help in configurability, and ease of tweaking (we hope) as well as movement patterns, etc., etc… also we plan to control it using USB joysticks, one or two and possibly foot pedals, gear shift if needed… of course keyboard commands are expected to be needed as well.
Now obviously utilizing hydraulics of this size this cant be run on a 12v batterypack lol… I’m thinkin 6 or 8 cylinder diesel will do the trick for driving the hydraulic pump (or pumps if more than one is needed). The reason for specifically a diesel engine is 1. the ammout of raw torque they throw out. 2. it can be tweaked to run on about any flammable liquid… with the skyrocketing gas prices this alone will help keep project and operation costs to a minimum.
oh… Jack, I’d imagine the speed at wihich it can move will be dependant upon the speed and power of the pump(s) and engine that’s utilized… also thats apart of the programming part… the controllers are analog… so as long as the program is written to utilize that it will be all that much freakin sweeter!
I suggest you get a hexapod kit, assemble it, and closely study how it operates. I’d think that riding hexapod would need anywhere between $10k and $50k investment. If it was an easy task, people would already be making them.
Possibly more. To make a 3DOF with RX64s, just the servos alone would run you close to $5k.
Of course if you didn’t need 3DOF legs on your hexapod, and make the one like in the video, it’s probably within that ballpark…
Ofcourse, shopping around for used aircraft and auto parts at junkyards can significantly decrease material cost!
But if you need a smaller scale model, zoomkat is right, just get a hexy kit and learn from it.
Beyond the difference of a servo-based hexy and a possibly diesel-hydraulic based one you’ll be building to ride on, you learn about gaiting and the physics and programming concerns behind the hexapod… great experience…
well that is true tom, but before that we need to know anything about programming otherwise we could build the thing and it wouldn’t have a brain and therefor be lifeless my two main concerns at the moment are
assume it was built and all the programming for the gait/stability/control/everything is done that wont do any good if its in a .txt format on the desktop WHAT PROGRAM READS AND EXECUTES IT? please! and 2) where do i learn to write said program? just the basics is all i need!
i can find the parts, design/build the full scale model and, if i build a small electric one first i can find everything for that thru here.
so, do i need to build a small one first? considering the time/money it will take vs. the amount of knowledge and experience gained? and will anyone here help us? even if its just to see a real honest to goodness advancement in fullsized combat ready mechs. were not looking to get into some tech college or show off at some expo. we are doing this as a way of life a way to advance and enhance this technology! if you can perfect walking and jogging what will come next? running, jumping,swimming,flying what else? we as man built and designed these machines. lets do our best to perfect them! make it so that its more than just a little bug that walks until it hits something! maybe we will fail who knows, but can you blame me for trying to make a dent in this world? our starting goal is to make at least 2 of these and with your help maybe it wil be easy enough to make 3 then all we will need is a pilot for the 3rd one(bait)
assume it was built and all the programming for the gait/stability/control/everything is done that wont do any good if its in a .txt format on the desktop WHAT PROGRAM READS AND EXECUTES IT? please! and 2) where do i learn to write said program? just the basics is all i need!"
You can do some research of previously developed robot projects using google and see what has already been developed. Lots of info in this forum if you search/read previous post. You can buy programming developed by others, or put out some effort to learn to write your programs yourself. Many people do it. Don’t expect people here to write custom programs for you or teach you to program unless it is of significant community interest.
“i can find the parts, design/build the full scale model and, if i build a small electric one first i can find everything for that thru here.
so, do i need to build a small one first? considering the time/money it will take vs. the amount of knowledge and experience gained? and will anyone here help us?”
You need to attempt to build a small bot first. If you can’t build the small one and learn the mechanics and programming from it, then a large size bot is probably out of the question for you.
" even if its just to see a real honest to goodness advancement in fullsized combat ready mechs. were not looking to get into some tech college or show off at some expo. we are doing this as a way of life a way to advance and enhance this technology! if you can perfect walking and jogging what will come next? running, jumping,swimming,flying what else? we as man built and designed these machines. lets do our best to perfect them! make it so that its more than just a little bug that walks until it hits something! maybe we will fail who knows, but can you blame me for trying to make a dent in this world? our starting goal is to make at least 2 of these and with your help maybe it wil be easy enough to make 3 then all we will need is a pilot for the 3rd one(bait)"
Don’t expect to be able to duplicate in the real world what you are seeing at the movies or what you see in your video games. Movies/games don’t have to obey the laws of physics.
Definitely start with a model. But there are considerable differences between a model robot, and a full-sized industrial control system to control 18 bi-directional hydraulic actuators! This is not a trivial task, and would be a very dangerous machine without proper design.
Controlling an R/C servo motor that can be “commanded” to any position in it’s travel is a little different then controlling a hydraulic cylinder. A closed loop operating from feedback sensors on each hydraulic cylinder would seem to be indicated, but then I’m not an ME.
The mechanics would be a good senior ME project for a university student. Perhaps you can divide up the project, find an ME to do the mechanical stuff? And an EE to do the electronics, and a CS to do the programming…
Then there are the safety issues. This would be a very dangerous machine if operated incorrectly, or if a failure occurred! I hope you’ve got insurance!
Aside from that, it’s a very interesting project! Above the “hydraulic system” layer, a good industrial controller computer running a deterministic control program would work in a comparable fashion. Move joint nn to position mm, all times 18DOF!
Sorry if I appear to be against or down on your project. I’m not, actually, just concerned!
And where would you build it? It sounds like you’d need a space the size of an aircraft hangar. Not to mention the police and/or military attention it would likely generate if it ever got moving out in the open. Incoming!
Well… as far as authority goes we’re not too concerned as this thing wont be that huge…nor will it be equipped with weapons… well ok… paintball guns maybe.
If I were to die building/testing… well there are worse ways to go out.
