After completing the autopump i realized it would be very usefull in a construction equipement. But i wanted to build omething special, unlike the usual classic machines. This is why I chose a walking excavator type of a vehicle.

To lift and tilt its legs I used pneumatics, because they are better in routing tubes over the complex joints on which the machine rests. For operation of the arm I chose LA's due to their ability to accurately move loads with little jerking.

So here's the excavator nice and tightly folded.

The legs are spread and the boom begins to lift:

The four legs are than lowered therebye lifting the whole excavator up some 10 cm:

As you can see each of the tracks has its own M motor, the total number of motors being 11, all M type:

Feeding on some bricks:

And spewing them out:

The underside of the bottom showing the two autopmups used to lower and spread the legs:

And the video of excavator in action:

All in all I am quite pleased with the model, especially the pneumatic side of it. Its really fun to play with it, lift it up and dig out the bricks.

There are some things bothering me though:

The legs bend too much sideways

The speed of the superstructure is a bit fast

Pneumatics are unstable unless in maximum lowest or highest position

Long wheel base makes skid steering hard

What'ya all think?

Cool,at last you have made something that appeals to me.

I think Mini LA's might of been better for the stabilizing.I think you just need stronger pivots on the legs which may help the bend of them.

Yes the superstructure rotates faster than a F1 car going round a track.

The legs are a bit long making them smaller may help the steering,also if you have elastic bands to make the tracks grip better it may also help.

You can prevent legs from bending by using two sets of tracks on each leg, one on each side.

I love this technical and mechanical masterpiece it is so complicated and very well executed!

Nice video. It reminds me of the robots you see in Half-Life:

How did you get the cylinders to retract without attaching another set of hoses? I'm baffled!

Looks really compact. With a little refining you could probably fix the bending of the legs. I would use a smaller bucket as well.

tim

Nice video. It reminds me of the robots you see in Half-Life:

How did you get the cylinders to retract without attaching another set of hoses? I'm baffled!

my guess is gravity.

grtz

By using this little part, and some pneumatic switches you can make both pressure and vacuum to control the pneumatic pistons.

http://www.bricklink.com/catalogItem.asp?P=4692

This is how it was done in the "old days", but it is way more efficient to have pressure on both side of the piston.

What an awesomely great model!

Another one great machine from you.

Good job! :)

Really awesome machine.

Similar legged excavators I have seen for cleaning rivers (two wheels and two legs).

I like the combination of pneumatics and LAs. Really good. Using LAs only it would be much more complex.

I wonder if you plan to create version nr. 2 to solve the issues that bother you.

Awesome MOC Zblj.

This is really cool, I haven't seen something like this before and your's is great! The video shows it off nicely

NASA called, they want their rover back!

:)

great model