Variable geometry tank climber

[oracid]

In this video, I show that it is possible to make a reasonable sized tank for a private house which is able to climb stairs.
To climb stairs, a tank sole must be about 62cm length. With such a sole, the tank reaches about 85cm total length.
The variable geometry makes it possible to make a 55cm tank length, which by unfolding, reaches the 62cm necessary to the rise.
 

 

[Beck]

Ingenious and effective! I like how you are able to communicate your message without speaking in your videos.

[Davidz90]

Nicely done! How it keeps the track tension? Is the track exactly the same length when folded and unfolded?

[dagupa]

That is a job done. Nice tank. Two question: Does the EV3 control the fold/unfold function or you use the Remote Control? How do you power 6 motors with one EV3?

[Leonardo da Bricki]

Awesome tank-crawler! I like the automatic (?) folding mechanism. Very cool design.

[oracid]

Thank you for your comments. 

 

- to drive 6 servos, I use this : http://www.mindsensors.com/ev3-and-nxt/21-multiplexer-for-nxtev3-motors

- yes I use the EV3 remote control to drive the tank but the geometry modification is automatic, I use the EV3 Gyro sensor, testing angle of the tank.

- the size of the track is not the same on the both perimeters. That why I realy modify the perimeter lenght with an actuator. You can't see this in the video. I will make pictures soon of that, but from a new version which is stronger and too heavy and unfortunately does not work.

 

 

[Jurss]

Interesting thing.

First I thought, that there is some neighbour outside window, thena I realised that it is You in mirror :)

[oracid]

Here are some pictures of the new version. You can see how the actuator modify  the length of the track.
In this new version, I have used the @efferman Gear rack beam, https://www.shapeways.com/product/4QE5P2AC9/gear-rack-beam-4l?optionId=41744256&li=user-profile , thanks to him.
Unfortunately, this new version does not work, it is much more rigid but much too heavy.

 

Edited November 13, 2017 by oracid

[Aventador2004]

How familiar these videos are, i watched them when they were first posted.

Nice work! 

[Isak]

this is ingenious! make a double sided one?

[oracid]

3 hours ago, Isak said:

this is ingenious! make a double sided one?

Thank you.

Yes ! I though about it, but Lego servo are too big and not much powered.
My goal, making that kind of tank, is to make something little. Maybe with non-Lego servos.