Currently, Moment Skis uses Ultra High Molecular Weight Polyethylene (UHMWP) as the material for their ski sidewalls. Because of the type of material, it needs to be flame treated before it can be used in ski production. Moment Skis currently uses a propane blowtorch to flame treat the sidewalls by hand. This can take a lot of time to do and creates inconsistent results. Team Fire on Ice’s goal is to design a machine that will increase productivity and heat treat the ski sidewall at a consistent temperature and duration.
The main specifications of the Ski Sidewall Heat Treatment Device (SSHTD) include being portable in in industrial environment, move the flame treated sidewalls into a collection box, have variable motor speeds, have an adjustable flame, and the device must support the UHMWP sidewall at all times.
Proof of Concept
Team Fire on Ice’s proof of concept (PoC) focuses on how effective the heat treatment process for ski sidewalls made with Ultra High Molecular Weight Polyethylene (UHMWP) with respect to the amount of time that the UHMWP material spends in the flame. The device used in the PoC will be using a wheel to pull the material into the flames and the speed will be controlled by a variable motor. This speed will be changed to find the minimum speed that will keep the material from melting and the maximum speed that will be fully heat treated and have the material stick to the binding agent used in ski manufacturing.
So far, Fire on Ice has yet to build the machine but plans to do all of the building and testing before the start of the Phase 2.
The plastic that Moment Skis uses in their ski sidewalls is Ultra High Molecular Weight Polyethylene (UHMWPE), and this material needs to be heat treated before it can be adhered with the epoxies used in their ski manufacturing. The treating process requires the surface of UHMWPE to be sanded, treated with a flame, and stored correctly. Team Fire on Ice will be concentrating their efforts on the heating process of the ski sidewall material by manufacturing a device that automates this process. The purpose of the device will be to eliminate human error and expedite the heat treatment process while also producing consistent results. The process will be up to ten times faster with the automated system, leading to a more efficient manufacturing process. This device will achieve these goals through the different design specifications and characteristics.
Product Design Specification:
The product design specifications presented by team Fire on Ice are simple and precise. Since the device will be used in a small ski manufacturing plant, it is a high priority that this product is not restricted to one location and is mobile. To prevent injury, team Fire on Ice has designed the product to not have any sharp edges which increases the safety precautions for the employees while decreasing the damage a mobile device could do to a factory. To further reduce hazards that the product can create, it must also be designed to meet OSHA standards for design and labeling. The two major design specifications for the product deal with proper feeding and adjustable speeds. To properly feed the UHMWPE material, the wheels must grip it and send it through the system. This will remove the human error aspect that Moment Ski’s has been having. To properly guide the material through the system, there will be guide rails and base supports to ensure the material, even after the heat treatment, will be adequately supported. Having an adjustable motor speed is crucial to a reliable heat treatment because different ski sidewall profiles will need to move through the flames at varying rates. Fire on Ice has ensured Moment Skis that the proper caution labels will be placed on the system to warn users about the open flames and moving parts that the device features. Fire on Ice has improved their product design specifications throughout the design process and is confident that the system will be safe, mobile, and suitable for Moment Skis.
The Ski Sidewall Heat Treatment Device will use an electric motor to powering two wheels on the right side of the device using a belt and pulley drive system. These rotating wheels will push and then pull the UHMWPE through the flame region. The plastic will maintain a constant speed throughout the system while being properly supported to ensure no inconsistencies throughout the heat treatment process. The plastic will be fed on its side through the flame, positioning the top and bottom of the material to the sides. The material will be enclosed in a U-shaped channel and fed in such a way as to increase support before and after the flames are applied to the material. The two nozzles will be pointed horizontally towards each other to direct the flames properly at the ski sidewall material. After the sidewall material has passed through the flame region, the second driven wheel will advance the UHMWPE sidewall out of the machine and into a collection box. After completing all the necessary steps to heat treat the material, the ski sidewall will be ready for the following steps in Moment Skis manufacturing process.
The torch system was made with two Bernzomatic TS8000 propane nozzles. In order to make them usable in our device, the tips had to be modified. There were two Swageloks were swapped out for the 135 degree stainless steel tubes that were originally used. This allowed the torch to point the flame at 90 degree angles to its mounts and allows the flame to rotate relative to the hand-held device.
The electrical system only includes three parts. The AC voltage controller, the motor, and the outlet cord that would be used to hold them together. The only assembly for this section is to solder the cord to the two exposed wires on the motor and plug it into the controller.
Includes four mounted bearings, two rubber roller wheels with bearings and two without, a 7” pulley, two 3” pulleys, and a 2.1-3.1” adjustable pulley. No manufacturing was needed for any of these individual parts.
Shown are various nuts, bolts, washers, and lock washers at the top along with an aluminum rod, two aluminum angles, and a flat aluminum bar (all 3’ long) respectively from top to bottom. The aluminum rod was cut in half and threaded with a tap at ½”-13 threading 3” down. The aluminum angle and flat bar were cut to various lengths that are needed in the device.
Steel angle pieces were cut at various lengths and the ends were ground down to give a good surface for welding.
The first step of the assembly is to weld the frame together. This is done by overlapping the steel angles such that they create a 3’x3’x1.5’ box. After the box is done, a secondary layer positioned with a 12” gap between their closest surface and welded in place. The frame at this point should look like Figure 1.
Figure 1: Main frame built
Figure 2: Feed wheel assembly
Figure 3: Bearings mounted and feed wheels are partially assembled into their corresponding bearings. Pulleys not shown
After the feed wheels are positioned, the motor is mounted and an adjustable pulley was be added to its shaft. This was done by bolting the motor onto a piece of steel angle and slotting the steel angle where it attaches to the frame. These slots allow the motor to be pulled away from the pulley that it connects to so that the belt can be tensioned in the future if it becomes loose.
Next, the aluminum plate and the aluminum angle pieces had holes drilled into them and bolted to the steel crossbars. After that, an 18” aluminum bar, slotted along its short side, was added to the middle of the frame which also has holes to accommodate for the propane nozzle’s mounts. After the holes were made, the nozzle was clamped with hose clamps and the mounted to the previously mentioned aluminum bar.
The bottom of the frame needs three crossbars with one at the front and two at the back end of the frame. The one closest to the front helps mount the front wheels and the two at the back is used to mount wheels and support a propane tank without letting it move around. The last step is to attach the propane tank to the nozzles via the propane hose splitter and putting the V-belts onto the pulleys.
Testing and Results
The Ski Sidewall Heat Treatment Device (SSHTD) was tested with the same two tests from the Proof of Concept (PoC). These tests were the “Feed Test” and the “Heat Treatment Test”. The Feed Test is designed to check the feeding mechanism and ensure that it can support the ski sidewall, move it at a consistent rate, and keep it going along a certain path. The Heat Treatment Test was designed to find what speed causes the ski sidewall to melt when put into the propane flame.
This test is conducted by taking a ski sidewall and feeding it through the device and determining if it feeds as intended (passes) or has some issues (fails). Feeding as intended is defined as having the ski sidewall move continuously during its duration in the device and within the guiderails. Figure 1 shows the results of this test out of 30 tries. Only 4 of the experiments failed because the ski sidewall wasn’t flat to begin with and went over the guiderails. However, these ski sidewalls are already considered defective so they will not be used in ski production and therefore will not need to be heat treated.
Heat Treatment Test
This test was conducted by running the ski sidewalls through the mounted flame 10 times at different speeds. This speed was set at 160 in/sec (our minimum speed from our PoC data) and increased every 10 in/sec until the ski sidewalls doesn’t melt for 2 speeds. The testing ended at 210 in/sec and the data of the failures is recorded in Figure 2.
The only unintended failures were seen in the Feed Test due to defective ski sidewalls. This was fixed by having the operator of the device to check the ski sidewalls for a noticeably warped profile. The Heat Treatment Test was meant to find the failures and make sure that the normal operating speed doesn’t allow the sidewall to melt. If the ski sidewall does melt in the future, the feed speed can be sped up, the propane flow can be reduced, and/or the torches can be move further away from the heating area.
Purpose and impression
This device is meant to help heat treat ski sidewalls made of Ultra High Molecular Weight Polyethylene (UHMWPE) in a consistent manner and does so faster than it can be done by hand. Since the speed doesn’t vary as the ski sidewall is fed in, the speed won’t change given the amount of torque that the motor and pully systems output. This consistent speed is also lower than the speed of heat treating the ski sidewall by hand since that speed is 220 in/sec for just one side. Since the SSHTD heat treats the ski sidewalls at a minimum of 200 in/sec, this reduces the time to a little less than 50%.
This product reduces the time and effort for heat treating ski sidewalls significantly and Moment Skis, the client that this device was made for, is amazed by how simple it is to use and how adjustable it is to fit any ski profile that they decide to use. The extra time that is saved helps Moment use their labor in more important steps in the manufacturing process.
Meet the Team
Keegan Keller is part of Group 18 (Fire and Ice). He has spent his entire college career at the University of Nevada, Reno. While maintaining a 3.5 GPA, he has been able to participate in the two separate Mechanical Engineering Internships, join the Order of Omega, and be on the honor roll list for his fraternity, Sigma Phi Epsilon. He has lived in Reno his whole life and plans to leave sometime after graduation.
Corbett Fleming is a long term Nevada citizen, who grew up and attended high school in Boulder City, NV. After graduating high school, Corbett was admitted into several Universities throughout the country including California, Indiana, and Montana, but after much consideration Corbett decided that his home was in Nevada and enrolled at UNR. Corbett is currently in his fourth year of college and is majoring in Mechanical Engineering. Following his years at the University of Nevada Reno, Corbett wishes to continue bettering himself and his community by becoming a professional engineer.
Bryant Clouse was born in Henderson, Nevada and moved the Reno to study Mechanical Engineering after receiving an Associate of Science Degree from the College of Southern Nevada. He is currently the Risk Management chair head of Theta Tau, a professional co-ed engineering fraternity. After graduation, he plans on working in the robotics field and to possibly go back to school with the hopes of getting a second major in Computer Science.
Logan Jones was born and raised in Carson City, Nevada. He will be graduating in the Spring of 2017 with a Bachelor’s degree in Mechanical Engineering and a minor in Mathematics, all while achieving a 3.9 GPA. While going to school, he has held multiple internships that have taught him extensive design and testing skills. After graduating from the University of Nevada, Reno, he plans on staying in the northern Nevada area and working in the automotive design field. In his free time, Logan enjoys using off road vehicles, rock crawlers, dirt bikes, and snowmobiles in the amazing Nevada and Tahoe terrain.
Martin Cortez, though he was born in the state of California, was raised in Nevada for the majority of his life. He currently works at the University of Nevada, Reno as a teaching assistant for an instrumentation class and has graded and tutored for different courses in the past. His plans after graduation is to work in manufacturing.
Thank you to Moment for sponsoring the project and believing in Fire on Ice’s skill. Also, thank you to Ryan Tung for being the faculty mentor for the group.