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12

The material deformation you are seeing is called ‘plasticity’. It happens when a material under stress is deformed and doesn’t return to its original shape (this would be called elasticity). In many cases (and it is the case with LEGO ABS plastic), this deformation weakens the material (as mentioned by Kramii). To fix this part you have to deform it ...


11

When your function (such as an extending crane boom) gets to one limit or the other, this clutch gear ratchets instead of binding up the motor and all the gears in between. ETA: Forgot the second question. It has appeared in many sets, most recently the Fairground Mixer.


10

You will need to decide between 3711 Technic Chain Link and 3873 Technic Chain Tread, or possibly use them together. Each link of chain is about 1 cm long and 0.8 cm wide and you can get them in packs of 108 (Chain Link Set Product Code: 2000645) The Chain Tread are wider, but seem to be available only in smaller packs, such as Set # 9938-1: ...


10

They are not compatible, the teeth are completely different. Notice that the red old gear has 9 teeth and is the same size1 as a current 24-teeth, as illustrated by below: The axle hole however is compatible, so you could have a construction using both types. 1. Actually, the distance between axles to have two of these red gears mesh is the same as the ...


9

One of these? I regularly crushed these as a child. You could try inserting something small into the hole and gently easing it open. I've had modest success with a small screwdriver. Unfortunately, the gear will be weakened following a flattening. If it is badly squashed it is very likely break - either as you try to repair it or in use. Your best bet, ...


8

Quick answer: LEGO gear module is 1 (metric). See Section 3.4 at this link: http://bdml.stanford.edu/Main/CrawlerNotes The consensus seems to be the following: Lego gears have a metric module of 1, which is the same as a pitch of 25.4 teeth per inch of diameter. Pressure angle is likely to be about 20 degrees. (This is the most common angle with modern ...


8

These are 3 different versions one the same shape / function that fit over axle. The right one is the oldest from the 80 The left one came next The middle one came after that. To make it more confusing, lego is now back producing the right shape again What I can remember had the original one a lot of clutch power and was hard to be removed. Personal I ...


7

The first gear wheels, or cog wheels, were designed by Knud Kristiansen around 1964 or 65; the original Danish design patent was filed on March 1, 1965. Under licence by LEGO, Samsonite manufactured and sold these gears in the USA from 1965-1972, and in Canada from 1965-74. The gears had studs on the top and tubes on the bottom. They could be made turnable ...


6

Would this solve your problem? Depending on the direction of the input, only one axle will turn.


6

In this great GBC machine built akiyuki, you can see 2 types of conveyor belts. The first one is made of the small tread links (3873). The second and third ones are made with the large tread links (57518) He provides many videos and pictures through his blog and YouTube channel.


6

There are a number of ways to do this. This is one of the easiest and earliest methods: For that design, you'll need this part (3650): You can also do something similar using a combination of bevel gears or double bevel gears:


5

If you haven't seen it, Sariel's limited slip differential technique might do what you want, but it's a little different than what you are asking for: This setup doesn't provide a clean way of producing a fixed amount of torque to a wheel if it's partner is running free. It instead simply disables the differential if the wheels have been running at ...


4

I would tend to recommend some options which you didn't consider yet: using bevel gears, but actually use a combination of two gear on each axle: a 12t one (the thin one, as you say), and behind it, a 20t one (there you can use a fat one, which will probably be better). Another option is to use a worm screw, which will also allow you to change the direction ...


4

The two larger gears were produced from 1970 to 1974, while the smaller gear remained in production for three additional years. There are six sets released during that time that contained all three parts: 800 Gear Set with Motor (1970) 802 Gear Supplementary Set (1970) 803 Gear/Wheel Set (1972) 810 Gear Truck Set (1974) 811 Gear Crane Set (1974) 812 Gear ...


4

In this forum thread I have found the following tidbits: "We all know that XL motors can twist axles to their breaking point" This means 40 Ncm, according to Philo. "If you're looking to get max torsional stiffness, then stacked 2L axles + connectors would definitely be much stiffer in torsion than a single long axle." Axles can twist without breaking in ...


4

It looks like LEGO sells chain and sprockets, don't know if you'd have them lying around though. You could also try using pulleys instead. If you don't have any of the actual pulleys, take the tread off of two wheels and stretch a rubber band across, that should work too.


3

The Technic Riding Cycle theme features several bikes that may be of inspiration. One particular set Moto Cross Bike (42007) uses several 3711: Technic, Link Chain parts to make a chain. Based on Bricklink prices for the last six months, 39 chain pieces (the amount shown in the set above) would cost £4.29 (Aprox. $6.91 or €1.26). Pulleys and rubber ...


3

Dropping stones onto your LEGO doesn't sound like a kind way to treat your expensive Technic parts; I imagine that small bits of stone and dirt will fall through a belt of Technic Chain Link or Technic Chain Tread , what with them being a chain rather than a belt. This will then lead to other bits of your contraption becoming polluted with abrasive gunk. ...


3

In the case of this item, it means that the gear will slide freely along the axle it rotates around.


3

Problem solved. I had a part wrongly fitted. both parts look similar ( black gear wheel)...one(part#6012451) is smaller that other(part #4177431). back on track now. .. :-)


3

Well, the center diff allows the front and rear axles to turn at different speeds, which is useful to put less stress on drivetrain parts that are constantly moving around. However, for a Lego model it is probably not required, since it most likely would not move at speeds required to necessitate one. Building one in would add realism, but you would need to ...


3

The new gears are stronger and do not slide into the holes in bricks and liftarms. If you look closely at the holes in a brick (or liftwarm) there's a shallow, wider hole forming a step. This holds (for example) the collar in the middle of Technic pins, allowing them to hold bricks close together. Unfortunately that hole is big enough for the non-teeth ...


3

I don't believe there is any significant functional difference between these parts in terms of what can be built with them. The 10928 variant is simply a reinforced version of the original. This gear is widely used, but because of its small size, it has always had problems with breaking under high torque. It looks like this new variation is attempting to ...


3

According to Sariel's gear tutorial in chapter 5, Efficiency:, - the less gears, the better - the smaller gears, the better Based on this principle the first setup looks the best, but you are right that the 8 tooth gear is the weakest of all and it has the most backlash too, if any of these are valid concerns for your build. Note that gears can be ...


2

I don't think it's really possible to salvage it, as others said, you'll only weaken it more. Even if you can place it on an axle, there's a good chance it will break under stress. But replacement should be very easy to find, and don't forget you could also contact the LEGO customer service for that. It sounds a bit overkill, but they will usually happily ...


2

There are all kinds of situations where the front and rear axle may not rotate at the same speed. Imagine for example a bicycle taking a turn while remaining vertical. When viewed from the top (using a planar projection), the bicycle rotates around a point that's at the intersection between lines perpendicular to each wheel. Here's an ASCII-art illustration ...


2

The XL motor runs at approximately 220 RPM. Therefore, the following gearbox from the ELEC 201 class LEGO Design module from Rice should be sufficient:


2

I'd like to cover two other techniques that work well, they both transmit horizontal torque to vertical but in slightly different ways that I believe may be useful for different situations. Worm Gears Worm gears are fairly small (less than two studs long). Worm gears are designed to be operated in one direction and can only be driven by the axle with ...


1

You can use a worm gear for a compact, high ratio gearbox. By putting a worm gear on the motor shaft and using it to drive a 24 tooth gear you can achieve a 24:1 reduction. For high torque applications you could use multiple parallel axles held together by gears or wheel hubs.


1

Sariel's tutorial is one of the better ones, and his whole web site is worth while. The Eurobricks Technic forum also has a list of tutorials thread that you might find helpful. Sariel starts very simple and ends up with a discussion of what makes different variants on some of the Lego gears effective...



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