Walk N' Roll

Thanks bud. My biggest concern was the weight of a tracked power-train. They tend to be heavier than a wheeled design. But if one could use a light enough track and build the sprockets and idlers out of Carbon or Fiberglass, it might work.
Although without the ability to retract the wheels, like your design, I will be lacking alot of ground clearance when walking. Which defeats the purpose of having legs. I envisioned the legs being an alternate method of crossing rocky or otherwise impassable terrain on wheels/tracks. But if I only have 4 inches of clearance wen walking, there isn’t much 4" obstacle that large tracks won’t power over. So a Wheeled design is probably more practical.

I’ve been working on a light-weight sprocket and idler set for a custom track. And been slowly making progress on my HS-805 1/4 scale brackets and mounts. So I’m pondering if I should start on this. With a wealth of Hexapod programs and Tripod gait Programs for Hexapods, it would help compensate for my lack of programming abilities.

This is one reason I decided to go with wheels, plus the fact the bot will be able to steer each wheel independently. Depending on which leg design I use, I believe there will decent ground clearance when walking and the wheels are fully retracted.

This may not be true for the prototype with the SES body though - I have to take a closer look at that and will make some design changes to incorporate new stuff I have learned recently. After actually getting one of the U channels in my hand, I can see where I do not need to have three of them in the SES body - one, or two at most, should be plenty with some tubes of appropriate lengths to get the width I need. I’ll be able to reduce the overall bot weight by using fewer U channels.

Hmmmm… I wonder about using the tracks in combination with the legs. If the legs are used as helpers for the tracks to get the bot over rough obstacles, you might gain a lot of mobility and ground clearance might not be such an issue.

I don’t really think either of our designs are necessarily better - just different in how we implement things. I think in the end, it will be our software and how we make use of our hardware that will make all the difference.

Well, I think you should seriously consider working on this hybrid at some point. But then, I really like hybrid designs. :smiley: I can just imagine our two bots moving along together. :smiley::smiley:

Yes, indeed! I will also be able to use the hex programs since Walk 'N Roll will be able to walk as a hex when it is using its front legs for arms.


I would love to see 2 of these in action together. LOL Battle hybrid in the woods. :slight_smile:

Well I’m glad our chassis, drivetrain and arm designs are different. That way we can see 2 different versions of this idea. Maybe more if someone else makes one.

I can just see this idea cruising along the ground then stopping, unpacking it’s legs, and walking across a shallow stream, them back on the ground and off it goes. And for me, incorporating an additional 2 channels for for/aft and left/right control of the track ESC’s would be pretty easy. I think easy enough even I can do it. :slight_smile:

Can you say “Robo Magellen” now? :smiley: I very much want to build a bot that can have some chance of competing in such a contest.

Yes, the variety is nice. I am looking forward to working on the software. :smiley: Software developlent for Walk 'N Roll is going to be very interesting.

I originally got the idea to build a hybrid bot from looking at some stuff the Japanese have done. I don’t think there is much going on in the U.S. with hybrids unless it is NASA class stuff.

Oh yes! Two different hybrid bots toodling along together, helping each other as needed to get through obstacles. Maybe someday they will even be able to communicate with each other…

…sticking little signs that say “Degauss me” to each others’ backs… :wink:

LOLOLOLOL That was awesome.

Ha ha, yeah. :wink: Too funny!


I’ve been doing a lot of thinking about Walk 'N Roll, the number of servos it will have, etc. I am considering building it as a Hexapod instead of an Octapod now, since this will not take anything away from the overall design or capabilities I want it to have. Scaling back to a Hexapod configuration will also have the advantage of taking away 6 servos and the associated weight for 2 legs.

With an SES body for the prototype it will be easy to upscale back to an Octapod configuration. I am also redesigning the body to reduce weight even more.

The other advantage I’d gain to going to a Hexapod configuration is I would be able to take advantage of existing software for hexapods using the atom microcontrollers for the prototype. This would allow me to concentrate more on writing software for the special abilities of Walk 'N Roll which will require all new code.


Hey check this thing out. Scarey looking.

That movie is AWESOME! I wonder how it gets those wheels to roll? It has a very weird pattern that Ive seen roller skaters use to move. :smiley:

I’ve seen this one and it’s very cool. :slight_smile: In fact, this is one of the inspirations for Walk 'N Roll. I had the idea before I saw this, but this was what made me decide to actually go forward with Walk 'N Roll.

I did try to design a leg with a wheel at the end using the SES, but have not been successful - at least not so far. I have had a couple more ideas, but have not worked them out in CAD yet. My first attempts


I think it’s just like skating backward, your legs do kinda cerclis motions, that’s how it move by rolling, you don’t even need motors! anway, it looks prettys big, since it has a sevo at the knee, well I supose otherwie it wouldn’t be able to walk that fluidly…

This is probably where I went wrong with my design. I was including a servo/motor to drive the wheel at the end of the leg. Hmmm, I could use a ball bearing hub there and just use a servo to bring the wheel up into rolling mode.

However, programming the legs to do that sort of motion to get the wheels to roll would sure be an interesting exercise, to say the least. I don’t think I am quite up to that, but might try it sometime.


Thats incredible. 8)

I’ve scaled back on the body I will use for Walk 'N Roll for testing. Now, it will be a single 16" U channel with 8 pair of brackets attacked directly to it for the legs. This is a body I can actually afford to build and it will be plenty sturdy enough to handle anything necessary,

I can attack an SES electronics carrier direct to the top of the U channel to hold an ABB and SSC-32. Batteries can be held on with tie wraps. :slight_smile:


I would be. After all, there is a computer strapped to it’s back. :slight_smile:

The basic leg motion looks fairly simple (as I remember from skating many years ago). Position a set of legs a little to the rear so the wheels are pointing outward, then extend the outer arms outward causing foward motion. When the arms are as far out as practicle, move the arms foward so the wheels are pointing inward some, then pull in the outer arms resulting in more foward motion.

Motion that smooth is really tough with any robot or prosesser.