The Incredible Edible Rolamite!

Figure 1: Basic Rolamite Designs

(Just click to enlarge!)

When the lever, wheel, pulley, or wedge just won't do, the rolamite will get you through! Using the many marvelous properties of thin metal bands, the rolamite is a simple mechanical device with almost zero internal friction. The basic idea is that two cylinders can be held in place between two planes with a flexible metal band and roll back and forth freely. This basic design (kind of like the rollers that let drawers slide in and out, only less complicated) can be easily modified by bending or reshaping the metal band to create springs, dampening forces, "notches" where the rollers will want to stick... or pretty much anything else you can imagine!

Figure 2: A million uses! Personally I like the thermometer design using a temperature-sensitive metal the best.

(Just click to enlarge!)

Ball bearings can be substituted in most cases, but making perfectly spherical tiny metal balls is actually a pretty hard trick so most ball bearings areneither expensive or have some friction. Plus they always need to be kept clean, lubricated, and are hard to repair.

Of course many people have never heard of the rolamite. The people who discovered it in the 1960s were very enthusiastic about it's potential (see the link below for some rave magazine reviews and predictions!), but the rolamite can be a little hard to get your mind around, and, well, most people haven't heard of it, so they don't know how much they need it! But it's a great tool to think about, and the principle has been used in recent years to build super efficient devices... and we all know how important efficiency and energy conservation is!

Over the years engineers have settled a few great ideas that get used over and over: nuts and bolts, rubber o-rings, ball bearings, cheese-in-a-can. Sometimes it feels like the basic problems are all solved and we just have to apply the standard methods. But there are always special cases: for instance in extreme vacuums or lab clean rooms you can't always use screws or nuts because they can't be undone without oil in the threads (oil evaporates in a vacuum and can cause contamination. You can't use glue, tape, plastic, rubber, ball bearings, or cheese either!). So even wise old experienced engineers have to sit down and rethink the simplest machines and devices we usually take for granted.

Anyways, as you're thinking about your wild machines, keep in mind that even the simplest little ideas can be unique and world-shattering. And if you read this far go reward yourself with some cheese from a can, or at least a tasty sandwich and a glass of milk!

For more about the rolamite, check out these links!

http://www.rexresearch.com/wilkes/1wilkes.htm
http://en.wikipedia.org/wiki/Rolamite

Over and out,

Bryan Newbold
Physics '09
MIT mentor

Split Hairs and Chairs (oh, tables too!)

ADD: (By the way, there are 2 tables and 7 chairs).


Hi teams,

Chair and table dimensions unknown?!

Since the chairs and tables are replaced on a need basis and are so kindly loaned for our use from the Fay School, they are not all standardized. This means we have no information or guarantees on what they might look like. If you picture a plastic or metal fold out chair in your head or just a regular 6 foot-ish by 3 foot-ish table, that is probably very close to what you will be working with on competition day.

Even though the teams from last year have a sneak peak at table dimensions since they worked with them, there is a likely chance that they will not be receive the same kind of table or set of chairs. This puts everyone on even playing ground because this uncertainty makes it hard to base your designs on the height or width of these components.

If you are able to integrate these two objects into your machine on the day of the competition with some on-the-spot improvising, good! Being able to substitute one material for another or one mechanism for another is a sign of adaptability, which is a great thing for any engineer to have. We have full faith in your imaginative capacity! So long as you have an open mind that's always checking your possibilities, your machine will be able to adjust and calibrate until it's just right.

Hope this helps somewhat!

Happy Valentine's Day,
the MIT mentor team

How to do a Mobile Toaster:

We have already received a significant volume of e-mails requesting MobileToaster visits. We're so psyched that you're all interested! In order to ensure that we visit as many teams as possible, schools that apply in groups will be strongly favored over those who apply individually. We definitely encourage you to coordinate with other schools in your area to set up several dates that will work for you. If you are located nearby many other competing schools, you are welcome to appear on multiple applications. However, you may only submit one application as a host school. Once you have established a host school, please have them send us an e-mail including the following information:

1. Host Scool's coach's name

2. Host School's name

3. The best way of contacting the Host School's coach (phone number or e-mail address)

4. A back-up contact if we cannot contact the Host School's coach

5. The names of the schools (and coaches) that are going to participate in your MobileToaster date.

6. Dates and Times that work best for the participating groups

7. Expected number of team members (and alternatives) to be present. Please note: the workshop is only open to RGC participants.

Finally, our choices will also be based on whether the teams participating are new to the competition or not. Since we have a limited number of additional supplies, mentors, and time, we are trying to give as many schools as possible an opportunity to participate in the workshop. Unfortunately, we will not be able to visit everyone. Please have your host school contact us AS SOON AS POSSIBLE. Priority will be given to schools that apply before February 25th to allow us ample time to plan for our trip to your school. The more flexible you are with dates, the easier it will be for us to visit more schools.

Wow, what a mouthful!

the MIT mentor team

boooo-yah!