?

Log in

No account? Create an account
I, for one, welcome our 6 ton steel spider conquerors. - Adventures in Engineering — LiveJournal
The wanderings of a modern ronin.

Ben Cantrick
  Date: 2008-02-22 16:42
  Subject:   I, for one, welcome our 6 ton steel spider conquerors.
Public
  Tags:  reddit



The Walking Beast is a mechanical creature that walks on 8 legs! Weighing approximately 12,000 lbs, it stands 11 feet tall, 8' 4" wide and 23 feet long! It is capable of transporting 8 people including the driver. It has a step height of 41" and a stride of 5 feet!

The machine is powered by a 454 cubic inch chevy V-8 married to a modified TH400 trans coupled to two klune extreme under drive planetary gear boxes, uses a rockwell 2 1/2 ton military axle to supply power to the leg crank shafts, The final drive ratio is 125:1. The legs are supported on a 4 link system and uses 56 pivot points and 114 bearings.


http://www.moltensteelman.mechanicalspider.com/

http://www.youtube.com/watch?v=zXRjFEJNv5U

http://www.youtube.com/watch?v=al-CxNrLo6k

This is pretty darn cool. Are those Hoekens linkage for the legs? Good design. That way the feet move backwards in a straight line to propel, and then lift up off the ground and move forward in an arc to reset for the next step. Nice shocks on the feet too. Still not as quite graceful as I would expect, could maybe use some kinda series elasticity in the drivetrain?
Post A Comment | 9 Comments | | Link






  User: (Anonymous)
  Date: 2008-02-23 00:25 (UTC)
  Subject:   (no subject)
Somewhat obligatory...

I, for one, welcome our fuchikoma/tachikoma/uchikoma conquerors.

Do these come with a hot, female cyborg when you pop the hood?


-J
Reply | Thread | Link



Ben Cantrick
  User: mackys
  Date: 2008-02-23 22:33 (UTC)
  Subject:   (no subject)
I wish!
Reply | Parent | Thread | Link



osmium_ocelot
  User: osmium_ocelot
  Date: 2008-02-23 18:46 (UTC)
  Subject:   (no subject)
Would this qualify as a BGC Tech Watch? It reminds me of steps towards the Genki.
Reply | Thread | Link



Ben Cantrick
  User: mackys
  Date: 2008-02-23 18:59 (UTC)
  Subject:   (no subject)
I can't decide. Your call.
Reply | Parent | Thread | Link



Triggur
  User: triggur
  Date: 2008-02-23 20:23 (UTC)
  Subject:   (no subject)
Watching the videos, I suspect they need to do some re-design; the thing's feet hit the ground so fast and hard it's got to be hell on the mechanism.
Reply | Thread | Link



Ben Cantrick
  User: mackys
  Date: 2008-02-23 22:34 (UTC)
  Subject:   (no subject)
Yeah, it just hits the ground too hard. Maybe it needs more overlap between the "feet flat on the ground" portions of the movement cycle?
Reply | Parent | Thread | Link



Triggur
  User: triggur
  Date: 2008-02-23 22:40 (UTC)
  Subject:   (no subject)
Yeah, a redesign of the cam mechanism maybe. Theo Jansen's mechanism does it RIGHT:

Reply | Parent | Thread | Link



Ben Cantrick
  User: mackys
  Date: 2008-02-28 05:41 (UTC)
  Subject:   (no subject)
Looking at that, I think it would suffer the same problem. There's still not enough overlap time when at least four legs are touching the ground. Jansen's walker gets away with it because it has 12 legs.

What really needs to happen is that each leg needs to be 1/8 cycle out of phase with all the others. In particular, matching legs on opposite sides should be out of phase with each other, which they currently aren't. That way at least four feet will be touching the ground at any time, and since every leg is in a slightly different part of the walk cycle the transitions between steps will be much smoother.

Right now it's got kind of a horse-gallop or dog flat-out kinda thing going on. Both front legs touch at the same time and push off with full power, then both back legs touch at the same time and push off with full power, and again and again. It's bound to be bumpy, set up that way.
Reply | Parent | Thread | Link



Triggur
  User: triggur
  Date: 2008-02-28 14:11 (UTC)
  Subject:   (no subject)
Possibly, though my point was more that the foot's motion cycle is much more designed for a very soft putdown and pickup, and not a jarring, come-straight-down-at-30MPH *BANG* like the spider.

Perhaps some hybrid of the two...
Reply | Parent | Thread | Link



browse
May 2015