Gears transmit rotary motion and are commonly found in Technic sets.

learn more… | top users | synonyms

3
votes
2answers
49 views

Gearing down a PF XL

I'm looking for the best way to gear down a Power Function XL. I need to achieve a very slow output RPM (less than 1-2 RPM). I've tried a 625:1 gear (trough 40:8 gear). Can someone link to a well ...
5
votes
2answers
264 views

Any way to create a gear+chain, like for a bike?

I would like to create a LEGO bike. I can imagine how most of it would work, but i'm stuck at the chain. I need a way for the turning pedals (at one spot) to cause the wheel (in the back) to spin ...
9
votes
1answer
190 views

What's the purpose of the clutch gear in Power Functions set?

I have just bought this set and wonder the purpose of the white gear in the middle: How can you use it in your Lego Technic projects? Is it available in other sets?
11
votes
1answer
225 views

What is the difference between these hole shapes?

I purchased an assorted bag of LEGO Technic pieces. There are pieces with axle holes, but what puzzles me is that the holes are different from what I am familiar with. There's a piece with an ...
3
votes
1answer
338 views

How can I make a precise one-way clutch using Technic elements?

I need a mechanism so that if a (NXT) motor rotates forward, it moves one gear, but the other stays still, but if it rotates backward, the first gear does not move, but the second one does. I found ...
1
vote
1answer
112 views

How can I controll the speed of motor using gears?

Can anyone tell me how to use gear wheels to modify the speed of the motor in the Power Functions set 8293? I know I could use the remote control unit, but I need to have a fixed slow speed on a ...
3
votes
1answer
230 views

Pre-Technic gears?

I have this set of lego gears. I remember seeing them first at my grandparents in the mid 80's. They predate my firsts Technic sets (~84 or 85). I have fond memories of my dad building a 3-speed ...
4
votes
2answers
288 views

What is the difference between 8T gears “Type 1” (3647) and “Type 2” (10928)?

On Bricklink I can see that there are two types of 8-toothed gear - a "Type 1" (3647) and a "Type 2" (10928). It's obvious these parts are not the same, but what is the functional difference ...
6
votes
1answer
503 views

What are the torque limits of gears?

I am using Lego in the classroom to introduce students to geared machines. As part of this I am asking them to design a winch, using a small 1.5V DC motor and a collection of the common Lego gears, ...
2
votes
1answer
1k views

How can I transmit horizontal torque to vertical?

I have a setup where I have a step motor which I am attaching a gear onto. The motor will make the gear stand horizontal in a small vehicle. Is there any good gear combinations of LEGO gears that can ...
8
votes
3answers
2k views

How to make a conveyor belt with LEGO parts?

I am making a small robot with an Arduino and Technic LEGO powered by stepper motors. I am planning on moving small rocks throughout my machine. Does anyone have an idea of what kind of Technic LEGO ...
5
votes
1answer
464 views

Strongest gear configuration

I'm building a (what I hope to be) high-speed car using two PF-XL motors together and some gearing up. However, there's a point where I have to rotate the axle with power (that comes from the 3 speed ...
13
votes
4answers
309 views

How can I fix a flattened gear?

I have an old small gear that somehow got flattened to an oval shape. The axle hole is too narrow to slide a bar through, although it is not completely closed shut. How can I repair this gear?
12
votes
2answers
925 views

Are Samsonite gears compatible with modern Technic gears?

Do the old Samsonite gears (above) work with current Technic gears (below) LEGO bricks tend to be backward compatible with older bricks, but since I don't own any Samsonite gears I cannot tell.