Cal Poly Pomona’s Human Powered Automobile Staff, our June Hackers of the Month, designed and 3D printed practical bike elements utilizing PRO Sequence Nylon to race in an intercollegiate competitors. Calvin Iba, a member of the staff, describes his firsthand expertise.
Posted on June 5, 2017
by
Visitor Contributor Calvin Iba
Cal Poly Pomona’s Human Powered Automobile staff is a membership that designs and builds a recumbent bicycle and competes with it towards different faculties. This yr, we made a “tadpole” which makes use of two entrance wheels and one rear wheel. We used 3d printing to construct essential elements of the bike.
Cal Poly Pomona’s Human Powered Automobile Staff
As with every car, getting the right geometry is essential for good dealing with. This yr we used a brand new technique of fixing tubes in place for tack welding. We modeled 3d printable tube fixtures in strong works to carry the tubes on the excellent angles. Their baseplates have been sq., so we may use a straight edge to align them with different jigs and the tubes themselves. They have been printed in ABS filament because it has a excessive glass temperature. With ABS, there’s a excessive likelihood of warping, so the fixtures have been additionally designed to have holes within the vertical helps to attenuate warping.
Welding jigs 3D printed in ABS filament
Extra welding jigs 3D printed in ABS filament
Because the components didn’t must look fairly, they have been printed with a 0.8mm nozzle at 0.4mm layer heights. The fats extrusion width additionally gave the half numerous thermal mass, which helped when tack welding the tubes within the fixtures. The jigs didn’t soften in any respect. All our components have been printed on a closely modified Kossel Professional 3D Printer with a temperature managed heated chamber, an e3d v6 HotEnd mounted to an finish effector that I designed, and managed by and Azteeg x5 mini v3.
Printing PRO Sequence Nylon on the Kossel Professional
One other place we used 3d printing on the bike was in our chain routing system. That is typically an enormous downside for recumbent bikes, as a result of the chain is extraordinarily lengthy, having to go from the entrance of the bike the place the pedals are, to the rear wheel. After going to a few competitions, we’ve seen numerous different groups have issues with chain administration. Typically the chain turns into too slack and comes off the pulleys or gears.
Chain routing system 3D printed in PRO Sequence Nylon
We knew we needed to provide you with a dependable system, so we designed and 3D printed our personal pulleys out of MatterHackers PRO Sequence Nylon. We used inexperienced nylon from their colourful choice to match our bike. We went by means of a few iterations to seek out the optimum design that mounted to the bike cleanly, had sufficient energy, and was simply printable with out helps. Along with pulleys, we designed and made a series information, that stored the chain from coming off the crankset. Nylon was an ideal materials for this due to its low coefficient of friction. Every time the chain touched the chain information, it could slide simply. It paid off as a result of we haven’t had a single derailment of the chain. Though the pulleys confirmed put on after the occasion, they survived the excessive pedaling forces.
Chain routing system 3D printed in PRO Sequence Nylon
This yr the competitors was in Las Vegas, Nevada. There’s a design presentation, a pace competitors round a brief course, and a two-and-a-half-hour endurance occasion. Our staff continued to rise in rankings, putting 10th out of 25 groups. A spotlight for us was putting 4th within the endurance occasion. It is a very tough race for many groups because it exams the efficiency, reliability, and ease of use of the car.
Subsequent yr, we plan on iterating on our tadpole design and enhance the manufacturing of the body with extra 3d printed fixtures and an excellent higher chain administration system.
Wish to be our subsequent Hacker of the Month? Electronic mail [email protected], and inform us about your 3D printed creation – you can be featured in our subsequent publication. Hacker of the Month wins 3 free spools of PRO Sequence PLA or ABS filament to additional their pursuit of 3D printing greatness.