Middle School: A Mechanical Advantage

The second semester of the middle school elective, Intro to Engineering, takes on a special theme each year, and is intended for 7th and 8th Graders who are repeating the class. Last year, the theme was space exploration, and the theme was matched with our first annual Science & Engineering Expo, which was a huge success.

This year, the second semester theme is "Machines", with a focus on the simple machine types described by Renaissance scientists. We have looked at the history of modern and pre-modern humanity in this area, wrapped around such figures as Leonardo da Vinci, Archimedes, and Vitruvius (not the LEGO wizard--sorry!). As well as the artistry and ingenuity, we're also studying the idea of the physical concept of work, and how energy is conserved and transmitted in mechanical systems.

One of the simple machines that was studied in antiquity was the pulley--a rope wrapped around a wheel to change the direction of force. The compound pulley is even more interesting, and allows us to dramatically increase our "mechanical advantage". In everyday terms, this means that we can make ourselves stronger. But to talk about it is not enough: you have to prove this kind of thing outside!

Using Mr. Gill's outdoor education equipment and some 400 lb pulleys from Ace Hardware, the students themselves arranged the constituent pieces, hanging from the sturdy structure of the outdoor basketball hoop (not the hoop itself). On the previous day, they had worked with small model version indoors, so they knew how to set things up. It didn't hurt to have some Boy Scouts in the group, too!

Students working out how to set up the equipment

With everything secure and checked, and a safety mat below, the first student was hoisted up into the air.

Julian was our first contestant!

Pedro gets a taste of the air up there

Josh holds on as Pedro slam dunks!

Our particular compound pulley system had two wheels where the hanging student was located. This means that there are four lengths of rope leading away from the load. This gives a mechanical advantage of four, which means that, aside from friction losses, the person pulling is made four times as strong! If a 100 lb student hangs from the pulley, the person pulling only feels 25 lb.

Two wheels at top and two at bottom; the lower pulley moves up with the load,

while the upper pulley stays in a fixed position; note Sam's bowline knot!

Other notable moments possibly occurred as well...

Chloe representing for the girls!

Tommy and Julian being lifted together at once

Mr. Meadth showing a great deal of trust in Sam

Success!

Payback time for Chloe and Belen

More news coming up later this semester, and keep an eye out for this semester's Science & Engineering Expo in April!

Guest Speakers: Patrick Lindsey and John Horton

Last Tuesday, our Foundations of Engineering II class had the privilege of hearing from chief mechanical engineer, John Horton, team manager and driver, Patrick Lindsey, and Lindsay Lindsey, Patrick's wife, of Park Place Motorsports. Park Place Motorsports is a professional racing team that competes in WeatherTech, a branch of NASCAR devoted to racing sports cars.

John Horton stressing the importance of teamwork in racing.

Mr. Horton recounted his journey to a profession in the racing industry from his childhood fascination with his Erector metal construction sets to a life-changing auto shop program that he joined in high school. He stressed the importance of cooperation when working as an engineer, particularly in a field such as professional racing which combines a multitude of engineering disciplines.  On the matter of cooperation Mr. Horton said, "There's always something that you don't know about that you need a network to help you solve. Communication is key."

Patrick Lindsey explains the art of cornering in a race car.

Mr. Lindsey focused on the driving aspect of the race, showing data gathered from tire sensors during a lap at Daytona Speedway. He related the shape of the graph at a particular instant to what the car was physically doing at that point and talked about the importance of such graphs in making sure that the car was operating at absolute peak performance.

Our guests were also able to relate their profession to our recently (almost!) completed project: the robotic self-driving car. Jakob explained the various elements of his team's robot to Mr. Horton, such as the drive motor system and the rack-and-pinion steering, and Mr. Horton confirmed that the same features were present on their Porsche, just scaled-up and more advanced.

The Foundations of Engineering II class with their guest speakers.

The Park Place Motorsports Team ended their presentation with an inside-the-car video of a lap around Daytona Speedway and a directive to pursue their passion for science and engineering to wherever it may take them.

We are thankful for the visit from the Park Place Motorsports Team, and wish them luck in their upcoming 24-hour race at Daytona Speedway!

Project: The Self-Driving Car

We've recently reported on the Advanced Engineering I playground design project, but what exactly is keeping the younger group busy right now? If you pass by Room 401 most any afternoon, you'll find twelve freshmen and sophomores, six computers, three VEX robotics sets, two T.A.s, and one teacher very hard at work! The project? It's a little ambitious, but we are intending to design, build, and program three self-driving robot cars, in the manner of Google, Uber, Tesla, and a few others.

Just another typical day of class in the Providence Engineering Academy

The way of the future! But first a bit of background. Robotic cars fall into two broad categories: smart cars and smart roads. Smart car systems have all of the design and engineering and intelligence in the car itself, relying on GPS, lots of sensors, and careful programming. By contrast, smart road systems have some sort of marker built into the road itself to provide information to the car--one idea proposed in the past was to have magnets embedded into the road surface. While all companies are now putting all of their efforts into the "smart car" option, ours fall into the "smart road" category; we have a white line track on a dark background that shows the car where it needs to go. No white line means no navigation.

Left: the design brief and the plans for the roadway; right: the actual roadway,

newly constructed, mounted on an 8 foot by 8 foot plywood base

So what does it take to get this going? The number one resource is human intelligence; each of the three teams comprises four students, with distinct roles as follows:

• Team Leader: co-ordinate efforts, give attention wherever needed, be an all-around expert in everything, and keep a daily Captain's Log.
• Mechanical Engineer: primarily responsible for building the physical structure of the robot, mounting sensors, and attaching custom parts.
• Programmer: working on code that will navigate the robot around the course.
• CAD Specialist: design custom parts in a CAD program, and then print them out for use in actuality.

The beauty of this is that each member necessarily must work together with the others to achieve the outcome. The mechanical engineer needs input from the programmer as to where to place the sensors so that they work with the written code. The CAD specialist needs to also work with the mechanical engineer to decide what is most needed and where it should be placed. The team leader needs to choose just how to spread themselves each day to get the current priorities in order.

Ben (left) working on code; David (center) attaching his wheels to the frame

Samy, one of the mechanical engineers, putting together a frame for his

team's vehicle

Each team was allowed to choose between two types of steering design: rack and pinion, or a simpler design where the entire wheel and axle rotates around a central pivot. All three teams went for the rack and pinion, which is the same design found on modern cars. A single gear (the "pinion") rotates on a flat linear gear (the "rack"), which pushes it left or right, in turn causing the front wheels to point in either direction.

The custom CAD parts are another particularly exciting part of this project: the three CAD specialists are using the online platform Onshape to make pieces that are specific to their own robot. Just for fun, one team created a license plate with their team name, which is now proudly mounted on the front. Two teams are currently working on a box to hold a payload to be delivered along the route. The third team created a "shadow shield" to go underneath the vehicle and keep the line-sensing infrared sensors out of direct sunlight to make them more effective. The CAD specialists had to create bolt holes that match with the VEX robotics system, and they have infinite control over everything else.

One team's container design, intended to hold a small payload; a door is going

to be added to keep things secure until delivery

Another team's payload device is an open tray which flips up to release

upon command; note the square axle hole for connection to the motor

Both of the above designs are printed full size; so far, it looks like they will

be perfect!

The teams have another couple of weeks to finish this project, and they look to be on schedule for completion and demonstration.

Mr Meadth also decided that it would be fair for him to produce a proof of concept--can this really be done, after all? He used one of the spare middle school LEGO sets, which has an array of similar sensors and mechanical capability, but a very different coding language.

LEGO Mindstorms coding language--colourful blocks that snap together!

RobotC coding language, as used by the high school students--lines

and lines of colour-coded text

After a few hours of work, he came up with this smaller LEGO version, and it gets around the full track in about 18 seconds on its slowest, most cautious speed.

The LEGO robot car in action--note the three colour sensors in a bank on the

front; having three side-by-side allows for more sensitivity in response to the

car's exact position

Proof positive--it can be done! Upon completion, the robots will be demonstrated to the Providence community; we may go down to Lower Campus and show one of the elementary grades what we've done. Stay tuned.

Visit to UCSB Mechanical Engineering Department

On Monday of this week, sixteen Providence teachers and students took a trip out to UCSB, to visit the Mechanical Engineering department. Kirk Fields, Senior Development Engineer, met the group there and gave a tour of a few of the lab spaces.

The "clean room" was the first stop, and we noted that this is where Sarah Jane's father works to assemble his company's tiny lasers. We didn't see him through the window, but there were many interesting microscopic images of gecko feet!

The materials testing lab tied in well to what we have recently studied with our older group, Advanced Engineering I. Our students have been testing various materials in compression, carefully measuring the loads required to produce deflection, and deducing the modulus of elasticity--in layman's terms, a measure of how "springy" a substance is. This UCSB lab held dozens of industrial-grade machines to do similar experiments in compression, tension, fatigue, and so on.

Kirk (right) shows us the materials testing lab

Kirk was also able to show us a special research project, which involved a Perspex beam that "pushes back" when it a load is applied. Ordinarily, pushing on a beam would make it bend downwards, but this beam is equipped with sensors and motors that resist the action; this creates a beam with "infinite stiffness", so to speak.

The beam of "infinite stiffness" reacts and pushes back against applied load

We walked through some other spaces (including the wind tunnel), ending up in a robotics lab that housed an in-house competition much like what we do in our own middle school and high school classes. The college students design robots using a variety of motors, sensors, and LEGO structures; the robots ("rats") run around a walled-in elevated platform and collect "cheese".

One of the "rats" from last year is on display in the central case

The visit, though short, was well worthwhile. Jake, our senior, recently applied to this college and this department, so he was glad to meet some people and get a firsthand look. Mr Hurt, also present, graduated from this campus, and happily reminisced about times past.

All in all, a positive experience, and we're grateful to UCSB and Kirk Fields for allowing us the chance to come by!

Upcoming Event: MS Final Challenge!

In the Providence Middle School, fourteen 7th and 8th Graders are working busily on their capstone project for the semester: the Intro to Engineering Final Challenge! Every semester, the students in this elective are given a game-style challenge to complete, which involves designing, building, and programming a robot using LEGO Mindstorms EV3 sets.

This semester's challenge is being played out on a large elevated plywood platform, 8 ft by 8 ft. Mr Meadth spent a happy few hours putting this together in the science lab.

Each team of two students must create a robot that can sweep the platform clear of various pieces of coloured "debris"; imagine a small robot whose task is to permanently keep a rooftop helipad clear of windblown trash. Two robots are running in each round simultaneously, and whoever pushes off the most debris wins.

Special note: the pieces of "debris" we are using are the game pieces designed by Eva last year for her high school Educational Design project! Naturally, they are printed on our mod-T printers, which are still running strong (and now only $299 on their website!).

There are significant challenges associated with this project. How do you keep the robot from falling off the edge of the platform? How do you actually have the robot find the scattered debris? Does it run a blind search pattern, or does it try to use sensors to actively search? What kind of locomotive means does it use? Tracks or wheels or something else? What if it bumps into another robot?

Let's introduce our competitors this semester:

Isabela and Lily with their wheeled wonder--note the absence of rubber tires

on the front wheels to allow sideways slippage when turning

Christine and Sofi with their light and fast Pretzel Bot

James and Dylan with an imposing bulldozer--note the ultrasonic sensor on the

front to look for debris

Zach and Alan also went with a tracked design, and a large superstructure on

top for style points!

Ma.kaha and Cameron put their colour sensor way out in front to detect the edge

of the table--not falling off the table is critical to success!

Asher and Sam have an armoured design that looks just plain scary

Masato and Isaiah did some late redesign work to try to bring down their weight--

the robot with a lower weight gets the advantage of being placed first

The students will be presenting their completed designs to the rest of the class this Friday. The actual competition will take place in the Boys & Girls Club gymnasium on Monday and Tuesday at 1:00 during regular class time. Parents and friends are welcome, and it promises to be a lot of high energy fun!

Scott Kelly at the Granada

Some of our readers might be aware of the historic experience of Captain Scott Kelly, the American astronaut who spent approximately a year on the International Space Station. Captain Kelly carried out over 400 scientific experiments in his time in orbit, did several spacewalks, and took hundreds of incredible photos. Since his return, he has toured round to various locations and shared about his experiences.

Providence has three Scotts of its own, and one of them--Dr. Scott Lisea--reached out to the Engineering Academy to invite some of the top students to attend one of Captain Kelly's presentations at the Granada. Jake and Kylie accepted the invitation with pleasure, and Mr. Meadth came along as well.

Captain Kelly was good enough to pose with Kylie and Jake

for a quick photo after the event

Scott Kelly was warm, engaging, and full of good humor. He described how he lacked motivation and discipline during his elementary and secondary schooling, and that his outlook changed when he read the stories of earlier NASA astronauts. He encouraged the audience to do what any good astronaut does: ignore the things they can't change, and focus on what they can. He described the physical and psychological challenges of living in an isolated structure for so long, and how he gained a strong friendship with his Russian cosmonaut partners.

Thanks again to Dr. Lisea for providing this special opportunity for our students, and thanks to Captain Kelly for setting a strong example of leadership and persistence.

Guest Speaker: Nathan Gates

Last Friday, our Foundations of Engineering II group was privileged to hear from retired aerospace engineer Dr. Nathan Gates. Dr. Gates has worked for many years at Astro Aerospace, based in Carpinteria, and is recently retired.

Dr Gates shows a telescoping boom design that he worked on

Dr. Gates' impressive career was mainly focused on thin, light, graphite structures, such as those used on spacecraft and satellites. His specialty was "deployable" structures, which are launched in a folded-up configuration and then unpackage once in orbit. One recent project will unfold over two weeks to the size of a tennis court, despite being launched in a payload cylinder only a few meters wide.

Students eagerly listening to tales of projects past!

Dr. Gates ended his stories with a memorable reference to Eric Liddell, the Scottish Olympic athlete, who famously stated "when I run, I feel His pleasure." Dr. Gates has worked for years in the aerospace industry to the best of his ability, designing and creating in imitation of the Great Creator, feeling His pleasure, and living Coram Deo—before the face of God. Our students would do well to take heed.

We are very grateful to Dr. Nathan Gates for sharing with us, and hope to have him again soon!