/diy/ - Do It Yourself

God, a mecha in a wheelchair is just sad.

>>1812019
>This time punching empty boxes.

jeez. talk about setting the bar low.

>>1812064
One step at a time :)

Tuesday I plan to bash this fellow.

>>1812019
well when the cardboardboxians from wolf 359 come to take over we know who to call.

>>1812038
This

>>1812019
How long has it been in a wheel chair?

>>1812038
Most mecha nowadays work off a 4 leg wheel system or off tracks.
We have the coding and the mechanical ability to build all of it, except for efficient legs that can keep balance beyond a shuffle.
>>1812019
Can the waist rotate? It'l risk unbalancing the thing a touch more, but I know as a martial artist that the key to practically all fluid movement is the waist. Arms and legs are good, but waist is better.
If in doubt, look at human anatomy for piston placements.

>>1813765
Believe it or not most of your balance doesn't come from your legs buddy.

>>1813765

It does, movement is a little janky because I ruined the actuator mounting bracket a bit. Can't seem to find a good clip of it, so here's the robot dancing.

>>1812019
I approve of this thread

>>1814350

>>1813765

Something I wanna do is make 2 of these 6 feet tall & strap them together for tank style steering. It would be bouncy as all hell (and much slower than this prototype) and technically be four legs but it would be fun to try.

>>1814508
There are more sophisticated mechanisms for walking.
Though rough surfaces are usually a problem.

>>1814525

>>1814525
The Theo Jansen mechanism is shit for walking on anything other than a flat surface. The legs come in way to flat.

>>1814530
Yeah, that's what I said.
I don't know of any mechanisms that work well on rough terrain, big wheels are a simple solution or stick to the roads and enjoy your walking robot.

for offroad capabilities there could be suspension pistons on the ends of the legs, a variable and angleable suspension that attatches the legs to the hip so leg assemblies can be raised and lowered, angled in 3 dimensions and be additionaly buffered. A hip gimbal should be added so the mech can lean to stay upright in uneven terrain.

WOW so cool

Cmon, it's the 21st century! You shouldn't be running a fixed walk cycle, but rather a dynamic one that takes feedback from the terrain via stereoscopic cameras.

>>1815194

a fixed walk cycle with suspensions and a dynamic gimble to angle the walking plane would be a usable hybrid.

>>1815215
>a dynamic gimble to angle the walking plane
You'd also probably need to shift the centre of mass dynamically, but that could be relatively easy to do by pivoting the hips and arms.

>>1815248
there should be at least 6 legs, so the mech can always have a stable triangle stance.

a hip joint to counterbalance makes sense too.

>>1815248

both sides should have independant gimbles for the legs.

so:
-suspension on every leg
- gimble for both leg assemblies
- hip gimble and hip suspension

the leg gimbles could be steered by moving your lower leg, the feet raising/lowering determines the forward/backward speed of the leg cycle (motor speed)

>>1813791
No, but for big robots and mecha it comes at the rough location of the lumbar vertebrae. They either need to have a knee joint similar to humans or (more easily) shift their weight from one foot to the next.
And considering that weight can be in tons, and the legs can also be heavy to shift, it makes it difficult for big mecha to walk on two legs with any sense of balance because they're moving their center of gravity constantly, which is something you don't want in big machines.
>>1814508
A good thing to mind for stuff like this, is while keeping a wide foot base is good, keeping the feet and legs closer together will make it easier to walk.
Look at human legs. When we walk, our feet are in a single line of motion practically. Compare that to apes, who need to waddle and are a lot more clumsy.
My best advice as a biokinteticist. Make the legs close, and leave momentary balancing to the feet. We walk on the inner foot, but the outer part balances us.

>>1816744
the stance should be wide for stability, but the hip should rotate so the feet land infront of the other.
a 6 legged system can walk without balance shifts.

>>1814525
>>1814526
>>1814530
>>1814540
>>1814597
>>1815194
>>1815215
>>1815248
>>1815271
>>1815273
>>1815273
>>1816744
>>1816763

Boston Dynamics "work from home".
Wow all the robotic engineers that think these ideas won't need a $10mil DARPA contract.

Stick an arduino in it!
These are like the gears in steampunk.
They fix everything!

>>1814525
can't be that hard, even dumb animals and insects can walk everywhere

>>1816988
Robots confirmed for dumber than ants.

>>1816982

> implying darpa had a use for monstertruck style fun mechas
> implying darpa would mechanicaly fixed walk cycles
>implying darpa works efficiently

arduino is indeed overused. simpler boards would do the trick for most, or simple hard wired actions. many use arduino to compensate for shitty designs.

>>1817005

insects have variable step height, length and self leveling suspension

>>1817090
And robot designers can't even figure out how to copy a fucking bug lmao

>>1817106
nature has a massive head start.

on the engineers: bureaucracy is a bigger problem. but i know that many engineers can be stuck in their arse and don't test their theories against actual reality.

>>1817234
Definitely lol I am an engineer, and I felt the pain of bureaucracy without real collaboration every day until I quit my job.

>>1817270
hey man, I'm at uni for mechanical engineering and I'm beginning to think I fucked it with my choice.
Do I stick at it or is it going to make me kms

>>1817356
Oh wow lmao you actually believe that guy is an engineer lol? If he is then it's no surprise why he isn't one right now rofl
More like he's 18 and trolling us all lol ;-)

>>1817106
The romans didnt have 80 ton carriages going at 90 kph

Any of you mech guys think about gyroscopic stabilizers? Not balance bot brains that control a complex motor system but physically spinning disks that basically manipulate gravity.
https://youtu.be/cbRwBDEkKMA

If you got a chassis/cockpit that balances itself having a dynamic suspension system underneath gets more doable. The legs no longer providing balance don't have to be as sensitive or complex. They have to keep up. Walking is repeating a controlled fall.

>>1812019
OP you need an opponent to challenge

Have you talked to any other mecha builders for these purposes?

Also pneumatic jacks and similar airbag suspension components instead pistons. Airbags can lift tanks and houses but can also throw a lowrider/jumper show car 7 ft in the air with the right valves. Picrelated can be converted to a pull when inflated system as well as push.
I imagine limbs with disk breaks in the joints so it can hold position against the force of airbags slowly filling to be released giving burst strength and quick moves. But the same set up can be filled slow and open for smooth slow moves. Figure the airbags act as shock absorbent pillows and the locking joints rigidity on demand.

>>1817468
no but they had your mom standing on the corner.

>>1818792
Oh shit nigga!

>>1818792

It always brightens my day when I see what I expect to be the begging of a shitpost argument, and It turns out to be a yo mamma joke.