Stabilising Mechanism for the Elegoo Tumbller Robot

Although the Elegoo Tumblerr Robot is advertised to be ‘Self-Balancing’, she is in fact quite unsteady and tends to tumble and topple over as she gains momentum in motion.

On account of her instability, I have designed a versatile support mechanism to be attached onto her, that can help with the provision of the further stability needed to precisely manoeuvre the upcoming obstacle course!

Among the array of potential implementable designs are omni-wheels and caster wheels. Since the integral wheels of the Robot are independently driven and controlled by two DC motors (≈ Differential Drive Motion), it is inessential for the additional wheel to be powered. Therefore, an Idler Wheel will suffice to fulfil the purpose of stability 〜 very common in three-wheeled differential drive systems.

○ Omni-wheels have small discs or rollers installed individually around their circumference. They are perpendicular to the turning direction, and help to drive the wheel with full force, and effortlessly execute lateral sliding motion.

However, it will be tough to manufacture an omni-wheel using a 3D-Printer, and none are available for purchase on Amazon ! ☹

○ Caster Wheels are self-aligning to the direction of travel and can execute omni-directional motion 〜 beneficial as the robot’s wheels only have one axis of motion relative to the robot !

They provide stability at high speeds, and will refrain the Tumbller Robot from unintentionally wandering off the intended path when travelling straight at speed or navigating a maze.

Upon careful consideration of strengths, potential weaknesses, and feasibility of implementation, I made the conscious decision of modelling a Caster-Wheel on Solid-Works to envision the Stabiliser and Tumbller Robot ensemble!

Caster Wheels are all-directional, robust and produce a self-aligning torque that creates tension to keep the wheels pointed straight whilst in motion. The flat shape of the wheel and heightened surface area escalates friction and physical resistance to skidding, keeping the Robot on course.

It is crucial for the attachment to be light-weight 〜 to not stress the DC motors further, without compromising the performance and functionality of the Caster-Wheel.

The initial intentions were to 3D-Print the Plastic Stabiliser components, and use pre-made Carbon Steel hardware to assemble and attach it to the Foothold of the Robot, accumulating to an additional 15g.

I am optimistic that the Caster Wheel Stabiliser will aid the Robot in the betterment of her manoeuvres!

It is becoming increasingly evident that the most feasible way to implement the concept of the Stabiliser is through the purchase of suitable, pre-made retail Caster / Swivel Wheel from Amazon. The wheel must be height ≈ 7/8cm to correctly fit beneath the FootHold, as intended.

I might have underestimated the magnitude of this caster-wheel compared to my rather little Tumbller Robot ☹

But I always keep a quote from my favourite show Grey’s Anatomy in mind .. “Knowing is better than wondering, and even the biggest failure, even the worst, beats the hell out of never trying.”

I now know that a caster-wheel is not feasible, and I really tried so we will move on..

I think the Law of Averages manifested itself in my Stabiliser Project because after weeks of unsuccessful attempts, I was able to add a very suitable stabiliser onto my Robot !

In secondary school, I had chosen a subject called ‘Technology’ for the Junior Cert, where our first project was to build a very cute Aeroplane out of sheet metal - to familiarise ourselves with workshop hardware and electronics. I had saved the model of the Aeroplane for posterity, but with each idea for the Stabiliser falling through, I realised that it was time for it to be dismantled and put to very good use !

I removed the rivets that were attaching the frame + two side wheels to the Aeroplane, and subsequently fitted it beneath the Foothold of the Robot with some double-sided sticky tape. I was hesitant to use a drill, nuts and bolts as I was very anxious of causing permanent damages, and surprisingly, sticky tape is proving to be very durable and strong!

I am pleased with the resulting entity of the Robot and Stabiliser, as it was not custom made or especially-designed at all ! Just a very lucky coincidence..

The addition of the two-wheeled stabiliser in the front alters the design of the Robot - lowering it’s centre of gravity and helping maintain greater balance, both while stationary and in motion !

I am hopeful that the added security will enhance the Robot’s manoeuvres through the very compact Obstacle Course, and prove to be especially beneficial, for when she must stay still and catch ping-pong balls at the end of the journey….. as so far, she has been toppling and spilling all her hard-earned collectables !

See You soon ! x

Related posts:

I am gonna be honest. I always thought critical analysis was a waste of time while reading. I have thought this way all the way up till I took this class. It was also something I always struggled…