Vex Hexapod frame, leg ideas and balancing

So, i’m building a hexapod for my biology class art project!

i have the frame done so far, but im not sure wut to do about the legs…
i’m thinking about using a cardboard cylinder type thing, with limit switches on the bottom.
Also, i foresee balancing issues, so i’m thinking about putting the battery in the center.

Anywho, tell me what u think; see anything imminently disasterous that will make this thing fail?

thanks for the help!

If I were you, I’d use the sturdiest Vex beams you have. You should also attach a pad to the feet so it doesn’t scratch up furniture and it will grip the ground.

I’ve had experience with bots like this (I once made a dog robot that couldn’t stay up) andlet me tell you advice:

Get the sturdies legs you can find (as I just said)

Make sure you have nothing hanging over or near the sides that might off-balance the robot

You MUST have all the legs synced perfectly (really hard)

Make sure the legs that should be up aren’t scraping the ground

Hope this helps:)

Would it be possible to sync up the legs by adding another gear between each of the leg gearing mechanism?

yea, i was thinking about that, but i ran out of gears…
i guess i could still do it if i made the thing smaller, and just interlocked each leg gearing.
I was also thinking about putting switches on the feat, so that each they sync by programming it to sense which feet are touching the ground.

as for sturdy legs… maybe ill find some pvc and mess with that

so here’s what i’ve added

i’m gonna be adding those bumper switches to the bottom of each leg, hoping for the best. the cardboard seems to be pretty sturdy

cool somebody made one of these a while back but i can’t seem to find the link to it it the gallery

never mind i just found it if you search spider under the gallery you will find it.

will you post a vid of it walking when it is done i am interested to see how it works. i understand the basic idea but this still kinda boggles my mind.

Great job on the legs and body. That’s some rapid prototyping!

i aught to find a way to make vex my homework.

sorry for the double post but i don’t think editing gets the thread a bump does it?

when you drive one of these do you write a program that says when you push the joystick forward walk forward and back walk backwards? and so on for turning? or is it like you have to push tons of buttons in the correct order and timing? i guess what i am asking is could you please explain your control for the bot? thank you thank you

So, mah hexapod is fully built. Turns out that the taller legs were really unstable, so i cut them down.

Here is a video of it working, i wish that it would go faster ;_;. But at least its doing what i want it to do…slowly. I’m manually driving the bot, but it will only go a little bit faster if i put it on auto walk.

So basically i have a bunch of if statements, that set the legs to different positions. (each leg has a bumper switch on it)
1 4
2 5
3 6

the left joystick forward causes an if statement, if switch/leg 1 3 and 5 are not pressed, move them forward until they are pressed.
Left joy stick back causes an if statement, if switch/leg 1 3 and 5 are not pressed, move them backwards until they are pressed.

The Right joy stick forward and back causes another if statement like the left joy stick if statement, but switch 1 3 and 5 are replaced with 2 4 and 6. Also they are moved forward/backwards until switches 2 4 and 6 are NOT pressed.

So when i alternate between left joy stick forward and right joy stick forward, the robot moves forward, and the both alternate backwards for backing up.

Then the buttons on the back are used for turning. I have another if statement set up.
If the left up button is pressed, move 1 3 and 5 forward and 2 4 and 6 backward so that 1 3 and 5 are not pressed and off the ground.

If the left down button is pressed, move 1 3 and 5 forward and 2 4 and 5 backwards so that 1 3 and 5 are pressed and on the ground.

The right side buttons do the the same thing as the left side buttons except 1 3 and 5 move backwards, and 2 4 and 6 move forward. This allows me to do both clockwise and counter clockwise turning.

hope thats not too confusing

nice job explaining. just to be sure to walk forward you would have to push one joystick forward to do 1 step the release that stick and use the other to take another step and so on. Correct?

if so i really like this while it would be kinda cool if you could have more or less normal controls were you push a stick forward and go forward till you release it the way you have it set up kinda mimics the steps that the bot is taking and i think that that is really cool. i tip my hat to you this is a really complex thing to do and you did it really fast and well. plus you are smart enough to make vex you homework.

i noticed that you shortened the legs. what kind of speed do you get out of it? my guess is it is pretty slow. what is this kind of bot good for like can it climb well or be all terrain?

Yea, the robot is pretty slow, but it can go over bumpy terrain pretty consistently. However, if the terrain messes up the switches, then im doomed to kind of just wobble around until the robot moves the legs enought to set them to the right switches.
This might be alot easier to program with quad encoders, or some sensor measures the of rotation for each leg.
It would be even easier if each leg was controlled by 2 motors like in traditional hexapods, where one motor moves the leg backwards and forward, and the other motor moves the leg up and down.
I kind of just programmed it randomly, i think i might try ur idea next, so that its easier to drive.

So… i changed the programming so that its easier to drive!

left joy stick forward goes forward, backward goes backwards, left turns counter clock wise and right turns clockwise
Its pretty much the same program, except it controls which legs move based on which legs are touching the ground and which ones arent.

i alright i am glad that i helped. before, did you have it set up so that to go forward you had to repeatedly push the right joystick forward then the left then the right one again?

after watching the video you posted it sounds like what i have described above it correct. i think i could hear the way you were hitting the sticks on the transmitter.

wow i just looked at you profile man team 1100 you guys rocked out there. i was on team 1768 (please don’t use our robots performance as a way to gauge my robotics abilities :rolleyes:;)) so yeah i guess we were both at the agannis funny we probably talked without even knowing it. i was over at your pit quite a bit over the two days.