The Design

This page is still under construction - lots more stuff to come.

First we constructed a wooden test robot to allow us to determine the correct gear ratios for the new motors and wheels. The robot needed to be quick but also it needed lots of pushing power. Using wood allowed us to make very quick changes to the positioning of motors and gears as they were just screwed own using wood screws.
Once we had the gearing sorted out we started work on the new chassis. Because we were using hydraulics the mounting points and main load bearing parts were made from steel, as was the lifting arm. The wheels would have to take the full load of our robot plus any lifted weight (another robot) so the whole bottom part of the chassis was also made from steel tube. Our lifting arm is operated by the converted 2 ton bottle jack used in Killdozer.
Here you can see the Ford Granda ABS pump with its oil resevoir in position. Behind it is one of the 4QD speed controllers and also one of the Bosch motors.
Another shot of the motor showing the gearing. A 12 tooth sprocket on the motor drives the larger sprocket , this is on the same shaft as a smaller sprocket which is connected to the wheels. You can just see chain going over one of the chain tensioners between the smaller sprocket and the wheel. There is another one tensioning the bottom half of the chain. Tensioners were needed to keep the chains on during fast turns.
Here you can see the other motor and speed controller behind the electronics box. This box houses all of the radio gear and interfaces to the speed controllers. A lid on the box cuts down the amount of interference from the motors and chainsaw getting into the radio gear.
Hydraulics in action - I weight the same as the robot.
Here we have a movie of the robot pulling my car. You need a copy of the Quicktime plug in to view it.