Base

large/small gears

launching armreciprocating mast

Large gear

Long linkage

Short linkages

Main support structure

Pathfinders

Hydraulic Gearbots are not all that common, but the fun thing about this one is that it is relatively easy to make, will amaze your friends, and you can toss popcorn around when your parents are not home (if you are a parent don’t read that last sentence). Also, your gearbot will be able launch marshmallows at friends for fun and profit (OK, maybe not profit). There is information about the different gears at the end, and if you read it our researchers said you could be 42% smarter! So lets get started! - remember to take your time, enjoy the process (take a break once in a while -while you let the glue dry) - and send us pictures! Questions or concerns? our email is at the end!

Gearbot

Hydraulic Gearbot

Rack and pinion gear

Launching cup

Scissorlinkage

Base

Riser

propellor

Dry Fit and taking it apartDry fit means that you put the pieces together before you glue them, this avoids the mistake of having it glued and then noticing that you used the wrong piece - and now things have gone sideways. It is really hard to get pieces apart once they are glued so we recommend fitting pieces together first, checking to make sure they are correct, then pulling them apart and sliding in some glue. Many of the parts are snug in the grooves, so you don’t need to glue them. As well, we designed this so you can take a lot of it apart and rebuild it (the Riser assembly is glued though!). We recommend taking some of it apart if you are taking it places (like show and tell at school - or into space!).

Also - take your time - enjoy the build!

We thought of calling it the “Rube Goldberg Interlinked Synchronized Hurl-o-mizer Thing-a-majiggy3000 XL” but the box wasn’t big enough… sorry.

1

Parts - There are a lot and this is the big picture! We group them into sections to make it easier (but not too easy!).

6

5

8

9

7

4

3

21

x 2

x 4

x 27

5

13

12

1110

14

x 2

x 2

25

17

15

7. rack gear and holders8. Dowel holders (2)9. Support top 9A. wood piece - fits into 910. - 14. see next page15. - 17. - see next page18. O-rings (34), rubbery

o-rings hold dowels in place. There are 2 larger ones to hold the sides together.

19. Linkages (6) two are longer (attach to part 20) and 4 are shorter.

20. large gear21. small wood pieces with

holes in the middle (3) 1 is 1 cm, 1 is 1.2 cm 1 is 3 cm - and it has a hole across it too!22. propellor - fun!23. dowel holders (2) 2

large ones fit together into the front of piece 6

23a. dowel holder on the other side of the front piece -624. Gears 1 large one (pinion for the rack!) 2 smaller ones - they mesh together!25. large dowel - with a hole in the middle26. Wooden balls (2) large one for the slider, smaller one to adjust the angle.27. Wooden piece - thicker - to hold the swing arm

19

21

20

23

22

18

9A

24

26

27

28 x 8

25. large dowel - with a hole in the middle26. Wooden balls (2)large one for the mast slider, smaller one to adjust the angle.27. Wooden piece -thicker - to hold the swing arm28. Round wood pieces - (8) - these disks have dowels glued into them - step 1!

5A x 3

x 2

2

Pieces - many are grouped on the next page - refer to the numbers there - if they are not here!

23a

Not shown: sandpaper, glue, base.

Parts: We have sorted them into the different paces where they are used.

1. base bottom 2. base top 3. base inserts4. base connectors 2 long ones and

2 shorter ones (4 in total)

Support structure5. Sides - they are

different! 5A. Support holders (3) -they hold the Support structure together at the top.6. Support base7. Rack gear and

holders - 3 pieces8. slider holders (2 of

them)9. Support top9A. Wood piece - fits into 9.

13

12

1110

10. Riser bottom11. Riser top 12. Riser sides13. Syringe holder 14. Syringe lock

12

1415. swing arm - 2 pieces16. swing arm holder 2.5 cm long17. launching cup18. 2 O-rings and elastic dowel - 10.6 cm2 holders (see next page)

1716

15

18

Dowels - a lot of them!26 cm - 1 - is the mast (with the ball on top!)22.5 cm - 2 - these hold the Riser12.5 cm - 1 - this has a small gear on one side and the propellor on the other side10.6 cm - 5 these go across the various pieces5 cm - 1 3 cm - 22 cm - 2 1.3 cm - 7 of them!

Lay them out as shown - and you don’t even need a

ruler! (but use one anyway!)

9A

7

8

6

5

9

54

3

21

Add glue to the area indicated.

Note!healthy snack!

rulerglue

Assemble these items:

=

5A

Base

Swing arm and supporting piecesRiser - this goes up and down

3

Insert 10.6 cm dowel into the small ball.

Easy!

Insert 3 cm dowel into the base.

Glue a few more pieces

Glue the dowels into the small wood disks. They will be the holders (they hold things in place).Gather 6 wood circular pieces (28)4 - 1.3 cm dowels 2 - 2cm dowels1 - 3 cm dowel1 - 5cm dowel

28

5 cm

2 cm 2 cm

1.3 cm1.3 cm

3 cm

Glue them in and make sure they are nice and straight!

Let glue dry!

When gluing, add glue to the hole, place a finger over the hole so the glue stays in, and twist a bit so it is evenly spread!

4

3

21

3 Make the Base

Insert the longer connectors lengthwise!

4Gather these pieces.

Insert the shorter connectors across the top piece.

10.6 cm Insert a 10.6 cm dowel into the large dowel and glue so it is in the middle.

2

1

Glue the mast.

Put glue in the hole, insert a 1.3 cm dowel and twist it around so the glue gets underneath!

(reciprocating is a fancy word for back and forth).

5 cm

3 cm

2 cm

1.3 cm2 cm

7 cm

NOTE!

Make the gears.Take the largest and the smallest.

Glue the 10.6 cm dowel into the largest, - and the 12.5 cm dowel into the smallest - add an O-ring first!

Use this one on page 11!

26 cm

small!

26 10.6 cm 21

12.5 cm

10.6 cm

Lay on a box while the glue dries to make sure the gears are nice and square (so they don’t wobble when they turn).

O-ring first!

Use your finger to keep the glue in!

25

24

1.3 cm

4

8

1

The shorter connectors are across - so the base inserts that slide in the long grooves don’t hit them! Double check!

shorter longer

Place the top onto the bottom.

3

3

Looks great! - let the glue dry.

Slide in the inserts.

You don’t need to glue them, if it is wobbly later then add a bit and let dry.

5

4 Make the support structure.

Insert the two round pieces into the side that has two grooves in the middle.

NOTE! the support structure pieces are different! - and they have to be facing the correct way when the pieces are attached!

7

8

Gather the pieces...

2 Large O-rings

96

5 5 7

Insert the rack and pinion holders.

7

Insert the rack gear into the grooves.

Looks good!

Insert the top into the side.

5A

X3

9A

Place the base onto the other base you made in step 1.

3 Base continued…

7

Up - then in!

Yum!

9

6

Insert the bottom into the side with the rack gear.

NOTE! Make sure base is oriented this way - with the larger round edge on the left!

larger

smaller

Add the large O-ring to the tab - there is a small groove to hold it in place.

Add the large O-ring to the tab.

Add the second side to the top and bottom.

Insert the thicker wood piece into the groove.

Insert the 3 support structure holders into the grooves.

9A

Now the riser! Assemble the pieces

11

13

10

12

14

Insert sides into the bottom.

Nice!

Insert syringe holders.

Make the support structure, continued…

5A

5

Piece 14 will be added soon!

Done!

Perfect!

Insert a 10.6 cm dowel joining the base to the support structure.The handle is on the gear side.

Slide an O-ring on the other end!

Slide the holder dowel through the base to keep it steady!

4

Place the support structure on the base.

O-ring!

Remember this?

Line it up like this!

6

Bottom Top

Bottom

Assemble the piecesInsert 10.5 cm dowel and glue the thick wood piece to the swing arm 2.5 cm from the end.

Twist the white elastic band and slide the second swing arm piece in.

Insert a small disc and dowel (1.3 cm) - any hole!

1.3 cm

Perfect!Insert a small disc and dowel (1.3 cm) into the hole in the cup.

Place the cup over the arm and put an O-ring over the dowel.

It will eventually end up here!

Add the dowel holders (two large ones).

23

Insert the smaller one.

Insert mast

Slide the mast into the round holders on the side.

Long end on top!

Slide down into the bottom holder.

Swing arm6

Dowel Holders on the base of the Support structure.7

Let glue dry.

Insert (any) dowel in the holders to make sure they are lined up. You will be gluing a wood piece to this later.

8

20

19

Longer ones!

The large gear mechanism.9 Assemble the parts.Some you made in step 1.

Slide 2 O-rings over the end.

1.3 cm

1 cm

Slide in 5 cm dowel.

5 cm

Add a small drop of glue to the corners of the 1 cm block.

7

2.5 cm10.6 cm

27

Make sure it is straight across!

All the way in!

Remember this?

Rounded edge on outside.

21

1.3 cm

23a

Insert holders into linkages and place in outside holes.

Add O-rings to the dowels, and the 1 cm block to the dowel - glue facing up!

Slide the dowel through the holders on the Support structure.

Add an O-ring to the dowel. Slide a linkage

over the mast peg - add an O-ring!

Make the scissor linkage.10

Gather the pieces.

Slide O-rings over the 2 1.3 cm dowels.

Join two linkages - add an O-ring!

Looks good!

Once the riser is on (next step) the second 2 cm dowel will go through the other end of the linkage.

Leave for a bit while the glue dries.

Block glues to holder.

Gently turn gear in a few minutes to make sure the dowel isn’t glued!

Remember these?

2 cm x 2

Insert a 2 cm dowel into the end of the 2 linkages - and through the holder and put an O-ring to hold it in place.

9 continued…

1.3 cm x 2

1.3 cm

Coming soon!

8

Now for the Riser!11Add O-rings to the 22 cm dowels and insert them through the top, the risers, and then through the bottom.

It should slide up and down smoothly!

Looks great, - add two O-rings to the long dowels underneath the support base!

Charge the syringes!12Gather the syringes, tube, and two O-rings.

Push the tube over the end of the syringe. It is tight - get an adult if needed!

Nice. It is a good idea to pre-stretch the other end of the tube with the other syringe - that makes it easier to get on the other syringe later (when it is a bit tight in space)

Looks good!

2 O-rings over the end.

Charge (fill) the syringe by placing the end in a cup and sucking in the water. Tilt it up and push all the air bubbles out so there are none in the syringe or tube - tap it with finger to dislodge any bubbles! - it should be bubble free!

Slide the water filled tube up the centre hole.

Attach the syringe to the Gearbot13Push the plunger in and push syringe down over the tube.

Looks good, You will be sliding the O-rings up the tube in a minute - but first lets attach it to the riser!

22 cm

O-rings

9

Push the syringe so the plunger is up about 1/2 way. Slide the top piece into the small groove.

Nice and snug! Slide in the syringe lock to hold the syringe in place.

14

No glue! - you might want to take it off if there are bubbles in the syringe and it is easier to fix with it not locked in!

perfect!

Push the syringe down into the base.

All the way! Slide the two O-rings up - use your nails!

Now to hook up some pieces to the riser.14Insert the 2 cm dowel with the disc attached -into the scissor linkage and then into the tab on the riser.

Add an O-ring.

Remember this?

Insert the dowel into the outside holes - and add an O-ring to the outsides to hold it in place.

Find the 1.1 cm block with the hole, and add glue to the corners (like last time!).

Ready to go! - push the plunger and see how it works!

13 continued…

1.1 cm

Insert 3 cm dowel into linkage - through block -then into tab on the riser

In, then back.

Add an O-ring and let the glue dry so the block is attached to the tab.

Swing arm!

Slide in, then back.

If the 10.6 cm dowel is loose in the block - then add O-rings to hold it in the center.

Glue on this side!

Awesome!

10

Now for the gears!15

Remember this?

Insert the large gear into the hole closest to the rack gear.Through both sides - and mesh it into the rack gear.

On the other side add an O-ring to the dowel, and glue on the outside.

Add the Mid-sized gear onto the dowel.

Slide in the smallest gear and mesh it with the other one.

Looks good, let the glue dry here!

Line them up so they are flat with each other and mesh nicely.You may need to move the O-rings a bit so they are holding it in place, but not too snug,

Add an O-ring so the gear on the other side is held in place, but not tight!

Add some glue - or if you want to carry it places - just add a bit of tape to the end and then the propellor has a friction fit - and it can be removed - so it doesn’t catch on things.

Add the propellor!

So that is it! - an epic journey to make the coolest catapult on the planet so far! Since most of it is not glued, you can take parts off and paint them, or begin hurling things!

Now What?Time to test out some theories - and maybe bust some myths of your own!

How does changing the length of the swing arm affect the distance and the trajectory of a projectile?

How does changing the angle of the Gearbot change the trajectory - and distance?

Does pushing harder have an effect on the distance?

Can you make a target and shoot for accuracy? is it hard to be consistent in aim?

Make up a game - get one of those mini basketball nets and shoot hoops!

ProjectilesIt is a good idea to test how the density of projectiles affects the distance they fly. Take some household items like cotton balls, rolled up tin foil, and other soft objects, like marshmallows and popcorn (hmm, what could we do with those I wonder?…) and the soft clay that comes with the kit and fire them off. Does the density of the item affect the distance it goes?The biggest problem of course is pushing the plunger with the same speed each time. Is there a way it can be pushed the same each time?

Finish your snack!(compost the core!)11

Hey - did you put the large ball on the mast?

Gears and levers are really interesting, and they transform energy in so many ways - increasing or slowing the speed of something, transferring motion from rotary motion (in a circular direction) to linear motion (in a straight line). Linear motion is usually reciprocating, which means it goes back and forth.

As young children we may have played with toys that used meshed gears to change the direction of the rotation, and while that can be useful in some situations, your Gearbot uses a linkages to “link” rotational movement to linear movement. There is a linkage attached to the platform under the propellor that moves up and down, and while it doesn’t do anything other than move in a scissor motion, linkages like this are used to stabilize machines so they didn’t wobble (wobbling is bad - it creates friction which is bad in machines).

Old steam trains used linkages on the wheels to drive the train, - that’s a really cool use of linkages and gears for a useful purpose. Not so many steam trains around these days, but there are still many uses for this kind of motion - check out linkages online and see what comes up!

On one side there is a Rack and Pinion gear - the rack is the flat gear and the pinion is round one that meshes with it. Rack and Pinion gears are most commonly used in things like power steering and windshield wipers in automobiles.The meshed pinion gear turns as you push and pull the syringe. The gear transfers the energy along the dowel to the other side of the platform, where there is a gear train. The large gear (11 teeth) there - meshes with a smaller gear (7 teeth), increasing the speed of the motion - back across to the propeller, which spins faster than the pinion gear it is beside. Can you figure out how much farther the propellor rotates compared to the pinion gear? The gear ratio is usually expressed by writing the number of teeth on one gear on one side of : and the number of teeth - on the other side. So the gear ratio for these gears is 11:7. When you go from big to small it accelerates the speed!

Meshed gears like this are used all over the place in cars, clocks (that are not digital!) machinery and printers and photocopies and many other similar machines that have to change the speed of movement. If If you ever get a chance to take apart an old printer (which we recommend! - but ask your parents first) you will see many cool meshed gears that all move together.

The rack and pinion gear is not used as widely as meshed gears are, but still, it is a cool way to transfer movement. Leonardo da Vinci seemed to really love using both rack and pinion, and meshed gears to change motion - as he drew many illustrations of gears in his codecies (the name of the compilations of his drawings). You can see his drawings on our www.pathfindersdesign.net web site. Busy guy!

Gearbot kit design, box and instruction manual and illustrations and text © Derek Wulff, Pathfinders Design and Technology, 2016. Questions, comments, concerns? please email us through our website: www.pathfindersdesign.com. and visit our .net web site for educational support and more on YouTopia - and all of our kits!Designed in Canada by Pathfinders 925 Clapham Dr. Victoria BC V9C 4G5

Pathfinders donates 1% of sales to protect, preserve and enhance the natural environment.

Gears and Levers

Some things…You have probably already done some testing - and you will discover many things about how gears work and interact with each other as you fire things around. Remember not to fire off objects at people! but if you do, make sure they can catch whatever you launch at them, and make sure they are soft!If you pull the plunger out of the syringe by accident (this happens!) - wipe up the water and refill. The best way is to remove the plunger from the Riser (remove part 14) and then slide the syringe in the machine up and remove the tube from the syringe. Refill the syringe with the tube and re-insert the same way you did when making it! If there are bubbles in the syringe and it doesn't have the power you want (air compresses!) remove the syringe and refill - easy!Make a target, or build a wall and hurl your happy ducks at it and knock it down - real life demolition!