January 2021 Newsletter

GNCTR is Coming up!
The time has finally come for the Great Northern Concrete Toboggan Race 2021! Our team is making the final preparations for the remote competition starting on February 3rd. The competition will hold remote events starting with Opening Ceremonies on the evening of the 3rd with events every day until Closing Ceremonies on the evening of the 6th.

Spirit Team Update

The Spirit team has been hard at work completing the videos for the Opening Ceremonies, spirit challenges, and making costumes for our team members. For Opening Ceremonies, our team created a Bogglympics themed video to introduce our team and theme to the competition. Even though the competition is remote, we still made costumes for all of our team members to wear for competition calls. To the right you can see the team mascot costume, handmade by one of our talented leads. Some spirit challenges for GNCTR have already been released for our teams, so our spirit captains have also been working on those too!


Overview of Toboggan Design
One of the most important parts of GNCTR is the technical report which outlines the toboggan design and safety considerations. With the competition just around the corner, we wanted to share all of the hard work of our Design Team!


Steering

This year the team uses an innovative hybrid electro-mechanical design that employs fully mechanical steering for the front skis and high-resolution encoder that will measure the angle of the front skis. The rear skis are individually steered
with a geared down brushless motor and encoder to create what are essentially giant servos. A raspberry pip computer serves as the central control, by taking the input from the encoder on the front and using the equivalent translation to move the rear skis to the correct position. This design allows for one-to-one translation where the rear skis maintain the same angle as the front skis. Alternatively, the ratio can be varied so the rear skis have a smaller rotation than the front. The system can instantly change between different modes to allow the driver to adapt to the run for optimal performance.


Braking
As last year’s braking system was so successful, this year’s design is very similar to last year’s. The assembly consists of two “truss-like” aluminum side members with 90 ̊ angled aluminum brackets connecting to the modules. When deployed, the plates swing in the opposite direction of the motion of the toboggan towards the snow. The rotation of the braking system is stopped by rods connected to the side of the chassis. The plates penetrate into the snow at a depth that can be varied based on race day conditions.


Shell

The shell design for this year was built upon last year’s design. The aerodynamics of the shell were optimized to decrease the drag force generated during the toboggan’s descent. This year’s design features a tapered rear that reduces the low pressure “wake” region behind the toboggan
that
that’s responsible for a significant portion of drag. Additionally, the front of this year’s shell has a more streamlined
shape that guides airflow around the toboggan. This year’s design features a 64% improvement on the drag force of the 2020 toboggan in aerodynamic simulations.

Running Surface
The concrete mix for this year is an Ultra-High Performance (UHPC) Concrete adapted from previous mix designs. The UHPC mix allows the toboggan to have thinner, and therefore lighter running surfaces. Two types of skis were designed: a modified-V for racing, and an Inverted-V for steering. These ski designs could be switched out for the different race events.


Chassis

The chassis is made of aluminum to reduce the weight of the toboggan and was designed for optimal points of connection for the other subsystems.


 

Bogglympics
Our team wide Bogglympics competition has been going great! Check out a couple of the judges favourite entries so far. To the left, one of our team members was feeling crafty and made a minibog. Another team member took a little plank break on his road trip.


Tbog Interview!

Our incredible co-captains Elisabeth Gagnon and Georgia Collins were interviewed by the Civil and Mineral Engineering newsletter! Read their interview here: Newsletter Article


THANK YOU WSP

OUR SPONSOR OF THE MONTH

Thank you, WSP, for your dedicated support of the University of Toronto Concrete Toboggan Team!