CLAIRE DU
Age 16 | Calgary, Alberta
Calgary Youth Science Fair 2018 Top Intermediate Award | Canada-Wide Science Fair Finalist 2018 | Queen’s University Applied Science Award
My objective is to design and build an innovative machine to reduce overall labor in lifting, rolling and moving eight 4x16m 100kg gymnastics carpets. I was a national level rhythmic gymnast. In the past 30 years, the Chinook Gymnastics Club has been using two dollies to lift and transport big and heavy gymnastic carpets daily before and after training. I have seen parents sweating and heard gymnasts complaining about the old dollies. There must be a better way to do this labor effortlessly. Target users for this device are gymnastic clubs or any other sports clubs using large heavy carpets such as wrestling, or any public facilities moving large area carpets.
HYPOTHESIS
I hypothesize that a modified carpet lifting machine can be designed to cut the labor from 2 people to 1, reduce the constant strength required on the back and hips, and make maneuvering and turning more effortless; under budget and safety standards.
INTRODUCTION
Innovation Process & Timeline
See Table 1 for innovation process and timeline.
Table 1. Innovation process timeline.
Design Criteria and Limitations
Safety: Safe to operate for gymnasts aged 5-16.
Save Labor: Cut labor from 2 people to 1, reduce apparent lifting weight on back and hips. Easy to push, pull and turn with heavy loads.
Mobility: Must be easy to move around gym to reach all 8 carpets
Weight. as light as possible but strong enough to handle 100kg 4m wide carpet rolls.
Storage: No extra storage space for the new machine; similar size to the current dollies.
Electrical Energy: Cordless as there are very few power outlets in gym so long power cords may be required. May be difficult to include batteries and large automated mechanisms.
Cost: under fundraising target $800.
Current Problem Analysis
1. Rolling each carpet requires using a PVC tube which is the length of the carpet.
2. Moving one carpet requires two people using two dollies on ends of the carpet roll to lift at the same time using a “shoveling” motion; must push down hard with feet to gain leverage.
3. Must keep holding the dollies down while pushing/pulling the distance to the garage for storage, must cope with fixed turning angles with 3-4m turn radii.
Existing Designs
To brainstorm ideas for an innovative solution, three major sources were investigated and researched to analyze different existing mechanisms: local market (Home Depot, End of the Roll carpet store, Princess Auto, Wolseley), patents database and Internet search. The method of rolling and lifting used in both stores is not suitable for my club’s purpose considering mobility, cost, safety, storage space, etc., but this inspired the thought that a regular PVC tube specially coated to increase friction for rolling may work. Karle, Home Depot sales staff suggested using a simple ratchet system to assist lifting carpet rolls from the floor or by inserting 2 shorter poles into the ends of carpet rolls to aid lifting. Both Canadian and US patent databases were searched. No machine specifically designed for lifting heavy and long carpet was found, but this led to analyze the possibility of using pneumatic or hydraulic lifting, testing out various wheel radius sizes, position of fulcrum points, etc.
MATERIALS
Table 2. Material & parts specifications and price.
Brainstorming and Preliminary Designs
At this point, design ideas were split into two sections: Carpet Rolling Machine and Carpet Lifting Machine. A decision was made based upon design criteria and limitations to not proceed with the rolling machine idea and focus only on lifting carpets.
RESULTS
Final Design - Mechanism Behind the Technology
The hand truck applies a first-class lever. Fulcrum in the middle: the effort is applied on one side of the fulcrum and the resistance (or load) on the other side. A blueprint of finished design is seen in Figure 1.
Figure 1. Blueprint with SW view with nose plate extensions.
1. Force required to lift the carpet, according to Archimedes Law of Levers, saves 49% by using smaller front wheels.
Archimedes Law of Levers: F1×L1 = F2×L2
F1=Force acting down on one side of fulcrum
F2=Force acting down on opposite side of fulcrum
L1=Length from F1 to fulcrum
L2=Length from F2 to fulcrum
Final Design: F2=100kg x 9.81m/s2=981N, L1= 51.5”, L2=3”. Therefore F1=57.15N
The force required to lift the carpet is to be minimized. The innovation saves more force compared to previous dollies because it has a longer length of handle (L1) and smaller wheels (L2).
2. Applied calculated force to balance carpet when moving using
Archimedes Law of Levers.
3. The rolling friction was considered into design and calculated. Force of friction is easy to overcome because of omni (360°) wheels.
Rolling Friction: Fr = C × W
Fr – Resistive force of rolling friction
C – Coefficient of rolling friction for the two surfaces (wood and wheels)
W=mg (m is mass of body, g is acceleration of gravity 9.81m/s2) – Normal force pushing the wheel on the surface or weight of body (100kg).
The Rolling Friction of the design should be minimized. W=981N, C=0.035
Therefore, Fr = 981N x 0.035 = 34.33N.
4. Use extendable nose plate to support half of the length of the carpet, to save labor from 2 people to 1. Also saves storage space and makes delivery easier.
5. Use omni directional casters to enable free maneuver and turning.
6. Added 2 large pneumatic back wheels to make 4 wheels balance. They can absorb shock loads and provide stability in directional control.
Machine Building Procedures
Built prototype to test.
Replaced Tamarack hand truck nose plate with prepared bigger sized steel plates.
Welded 2 foldable steel plates to center nose plate with piano hinge.
Mounted on coil chains, turnbuckles and snap hooks.
Welded solid angle bar to reinforce the hand truck frame against bending.
Replace front rigid rubber wheels with rigid urethane nylon wheels to reduce rolling friction.
Budget & Fundraising
A total of $1150 was raised through GoFundMe in 3 days. The total cost to build the machine was $945 including workshop labor cost.
DISCUSSION
The prototype works effectively. It succeeds in cutting labor from 2 people to 1. The lifting force is 49% less than before. Pulling and turning the carpets felt effortless. However, there were 2 major problems found and solved. First, the lower part of support frame bent backwards during repeated trials with the heavy carpet. The bent section was reinforced with solid L-bars and triangles. Second, it was hard to push the machine over rubber running tracks at the gym due to the greatly increased rolling friction. This was not noticed and considered in designs. A solution was to replace rigid plain rubber wheels with lower friction nylon wheels. This improved the design but still was not as smooth as expected. Several other ideas were attempted to overcome the friction but eventually the method of operation was modified instead of the machine itself. It was resolved by tilting the front wheels off the floor and pushing forward on the back wheels. The finished machine can be seen in use in Figure 2.
Figure 2. Finished machine in use.
CONCLUSION
The carpet lifting machine was successfully designed, built, tested and is ready to use.
Labor is cut from 2 to 1 person.
The force required to lift a carpet was 49% less.
The force needed to pull the carpet was minimal.
Maneuvering the loaded dolly is effortless.
The next step will focus on making it more automated, ideally even autonomous. In the future, with more knowledge and experience, I hope I can make better versions of this machine to help more people.
ACKNOWLEDGEMENTS
This innovation project was supported by professional engineers, high school teacher, industrial owners and sales staff, and sponsored by family, friends, Calgary community.
Gofundme – www.gofundme.com/clairedu
Jim Luo, Owner, Millwright, 3E Sheet Metal & Food Equipment Ltd.
Jay Xu, Zhong Gu, Senior Mechanical Engineer, P.Eng
Mr. Karbashewski, Science Learning Leader, Western Canada High School
Karle, Sales, Home Depot, Kevin Parkinson, Sales-Plumbing & HVAC/R, Wolseley staff,
Store Manager, End of the Roll,
Jacob, Sales, Princess Auto
Yu Yeliang, Architect
BIBLIOGRAPHY
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CLAIRE DU
Through years of experiential learning in STEM, I believe that hands-on learning to solve real-world problems can shape innovators of our future. As a national level rhythmic gymnast, I applied this belief to innovate a carpet lifting machine that solved a labour problem for my gymnastics club. This innovation reduces labour and makes lifting and moving big heavy gymnastic carpets easier. To combine my passion and contribution, I founded an emerging federally incorporated nonprofit organization, AI4Youth Canada, focused on connecting high school students, professors, and influential industry leaders in Artificial Intelligence across Canada and promoting AI related experiential learning opportunities.