Is that possible?

1. Would you like to produce more electricity from your model wind turbine? Is that possible? I could flap my cape at it! This PowerPoint and lesson are based on work by Ian Mitchell, The Green Egg Company, developed & edited by Amie Andrews for TLCP and Ali Ross, Sundog Energy.

2. Now I’m very confused! A gear system is a mechanical device that can increase or decrease the speed of rotation Is it possible to get more electricity without changing the blades on the wind turbine? Yes - if you use some sort of GEAR system! Gear what?

3. Don’t worry, I’ll explain. We use lots of gear systems in our daily lives. Look at this drill. Do you know how it works? The drill bit spins much quicker than the handle that is turning the drill.

4. cog groove • One handle of the drill is a _ _ _ _ _ _ _ to a big metal wheel. • On the back of this wheel are some grooves and t _ _ _ _ . • A c _ _ on the drill shaft fits into the grooves on the big wheel. • As the big wheel rotates the drill shaft turns q _ _ _ _ _ _ . • There are 60 grooves on the big wheel and 15 on the cog. How many times does the drill shaft rotate when the big wheel rotates once? t t a c h e d e e t h o g Drill shaft u i c k l y PART A. Fill in the spaces to work out how this drill works. 4 times

5. PART B. This is a rechargeable torch! How does this work? lever • When the lever is pressed the big white plastic wheel s _ _ _ _. • The teeth on the edge of the big plastic wheel turn a small c _ _ . • This rotates a gen _ _ _ _ _ _ very quickly. • Electrical energy is generated and this r _ _ _ _ _ _ _ _ a battery. • The battery powers the l _ _ _ _ on the torch. • 6. There are about 120 teeth on the big wheel and 12 on the small cog. When the big wheel rotates once how many times will the small cog rotate? p i n s o g e r a t o r e c h a r g e s i g h t 10 times

6. PART C. Here are some more gears that some of you may use quite often. But how do they work? • When we pedal the bike we turn a large cog with teeth on the e_ _ _. • This large cog moves a looped metal c_ _ _ _. • Smaller cogs on the rear wheel begin to r _ _ _ _ _ as they are pushed by the chain. • The chain can be moved onto different cogs to make cycling e _ _ _ _ _. • The large front cog has 60 teeth. The smallest rear cog has 12 teeth. If we turn the front cog once, how many times will the rear wheel rotate? d g e h a i n o t a t e a s i e r 5

7. Carpet brush Rubber belt Metal pulley Electric motor in here PART D. This is a bit more difficult to see. Look at this electric cleaner. How does this work? • When the cleaner is switched on the electric motor spins the metal p _ _ _ _ _ . • Then, a looped rubber belt begins to t _ _ _ the carpet brush. • The carpet brush c _ _ _ _ _ up dirt and this is sucked into the cleaner. • Think about it? Is the metal pulley spinning faster or slower than the carpet brush? u l l e y u r n l e a n s Faster

8. I think I understand gear systems. How do we use these on our wind turbine? First you must carefully take most of your wind turbine apart.

9. axle We made a pulley and belt gear system like the one on the cleaner. We used the corner of a cereal box to support the turbine, the axle and a large pulley wheel. We mounted the generator and small pulley a short distance away. We looped an elastic band over both pulleys. pulley

10. Our model worked and generated a little more electricity. However there were a couple of things we tried to improve. One was the V shaped notch that supported the axle. It was too easy for the axle to pop out of the notch so we glued a patch to stop this happening. You’ll probably need to adjust your designs too before they work really well. V shaped notch