Let's Make Robots!

Updated preview of new re-configurable, all metal tank chassis

Update: Just did a motor test using a fully charged 3S LiPo. These motor / gearbox combos are very powerful and will need a Wild Thumper controller to handle the peak current.

No load current: 0.6A
Nominal load current: 3A
Stall current: 11A+ 

This is definitely going to be the tank version of Wild Thumper!

I have increased the size of the battery compartment to take up to 2x 5000mAH 3S LiPo batteries and added a second deck for mouting more hardware. I've added mounting holes (same as Wild Thumper) to simplify the mounting of various hardware.



Recently I started work on a metal tank chassis that can change it's configuration using two metal geared servos. Here's a little preview. These pictures don't show the metal tracks (which are 45mm wide) and the design is incomplete but they will give you an idea what the final product will be like.

The default configuration provides the best "tread to ground" surface area resulting in maximum traction and is ideal for snow and mud over reasonably flat ground. 

This second configuration provides maximum ground clearance and is ideal for rought terrain and climbing large objects.

This front view shows that clearance is highest in the center making it harder for the chassis to "belly out" on rough terrain.

The third configuration can be used to clear an object caught underneath the chassis and also provides a large "tread to ground" surface area for better traction. Ground clearance at the front is low so this configuration is only useful for climbing stairs and any other situation where the robot might "belly out" but the second configuration did not work.

The fourth configuration provides a "Wall-E" style chassis. This configuration has a shorter wheel base which is better suited for maneuvering in confined areas such as mazes. 

The chassis can change it's configuration while maneuvering to suit changing conditions and should make it possible to climb stairs. These features should make it ideal for search and rescue challenges.

When I have photos and video of the prototype I will re-post as a robot project.



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Really like the way the robot changes configuration. It's well thought off. I've dreamt of building something similar for ages.
One thing I'd like to ask is about the treads. As the robot switches configuration, the effective length of the tread should change to keep the tread taut. How do you plan to accomplish that?

The front wheels are on a spring loaded slide assembly that can travel as much as 60mm to maintain tread tension.

Hi OddBot interesting robot thanks for the sneek peek, could also be known as OddBot builds a transformer, hollywood better watch out :D


I don't think it it quite sophisticated enough to be called a transformer. Wait until it grows arms and tries to shoot you.


Great idea OddBot. I hope that we can see the final build some day.

I guess the servos has to be very strong ones since they also have to pull/push against the spring-loaded track strain.

Yes, the servos are 13Kg.cm metal geared servos and as you say they must fight against the spring tension as well as gravity.

It's all a bit of a juggling act right now. Because of the configurability I must check every part in at least 3 different configurations to ensure that some simple modification to one part does not interfer with the other parts.

I've now spent over 60 hours designing this and it will probably be closer to 100 hours by the time the drawings are complete.

Right, and I bet the first prototype will fail as usual :-)

Anyway, great project and thumbs up. Hope you will get it working without too much drawbacks.

Odd I hope you do not mind me stealing your idea :) Must build something similar !

If this has inspired you to build something completely insane then that's fantastic. I look forward to seeing something creative on the front page :D

Is the total track length the same for all configurations? Otherwise I would see tension as an issue. It looks like an awesome piece of kit