Mini Mechanum ChassisTags: design, think, and innovate
To everyone's suprise, Garchomp didn't pan out. But, practice makes perfect, and that’s what we are going to do: create new chassis until we find one that works!
When looking for inspiration for a new chassis, we found the mini mechanum wheels that we had been fiddling with last season but eventually scrapped in favor of the larger wheels that can be seen on Kraken.
In the past, Iron Reign has been infamous for creating robots that barely fit within the sizing cube by a fraction of an inch, so we decided to take a different approach this time. We built a low-laying 6" x 6" robot to counter our older approaches. However, this new design meant that many of the pieces we had created in previous competitions would be unusable due to the changes in size and structure. For example, the way we affixed the wheels to the frame didn't work, as the axles were too big and the wheels were too small to use with our former wheel mounts. As well, these new mini mechanum wheels came with almost frictionless bearings, but the axle that fit within these bearings was hexagonal, unlike the round ones we usually use.
Justin first designed the axle plate below to solve this, but discovered that it raised the robot off the ground quite a bit, something we wanted to avoid, and it was very flimsy since it was so far away from the frame. We discussed these issues with our coach and brainstormed various methods we could use to attach the axle the frame in a more secure way; he suggested that we use a pillow block design that would have one side of the axel touching the frame. That way we would save space, while also having a lower-lying robot. This design worked out beautifully, leading to the design we are currently using.
The axles and wheels aren’t the only new thing about our robot: we're using motors with a gear ratio of 20 rather than 40s and 60s. This is another reason that we wanted to create such a minute robot. The gear ratio combined with the size will make this robot a speed demon on the field and allows us to dart between the minerals and the depositing location quickly.
In the upcoming weeks we will continue to tinker with this chassis design by adding a linear side and our gathering mechanism, and hopefully, we will be able to demonstrate it at the scrimmage next week.