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14

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


13

From this image, you can count the teeth well enough to determine there are actually 60 teeth, not 40: This does not appear to be a real part. It also appears you aren't the first to notice this. Jim Brickkeeper has created a ShapeWays model based on this movie piece which I found while searching for LEGO 60 tooth gears. According to Matthew Ashton this ...


12

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.


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

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: ...


11

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 ...


10

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 ...


9

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 ...


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, ...


9

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 ...


9

I found CAD files for LEGO technic axles here: https://grabcad.com/library/lego-technic-axles-1 and some gears which have holes for technic axles here: https://grabcad.com/library/lego-technic-gears-1 Using their online viewer I found the following dimensions (Which are a little inaccurate due to the limits of their online viewers tools. For more accurate ...


8

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:


7

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 ...


7

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.


7

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 ...


7

If you use a crown gear or bevel gear to connect your gears twice perpendicularly, they are exactly opposing each other, turn in opposite directions, and are parallel (if the respective axle is aligned to the coordinate system of the construction). Like with all gear-to-gear connections, you have a little wiggle room that may exceed half a tooth. If you ...


7

How can I get 2 opposing gear's axles to be perfectly parallel? Are there any good workarounds? You could use an idler gear. It will even out the offset. Yet, at the same time, it (or any odd number of idler gears) will cause both axles to spin in one direction. On the other hand, two (or any even number of) idler gears will not affect the asynchrony of ...


7

Likely you'll have the differential gears oriented wrong in the front or back section. The differential gear is this piece: Please check the instructions carefully and see if the orientation of this piece in the instruction book matches your build.


6

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 ...


5

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.


5

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 ...


5

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. ...


5

The torque in both versions would be the same. Your first version just adds 3 of these gears: The ratio between them is 1:1 so it will be the same as if you connect the axle straight into those small gears, as you do in the second image. (Well, technically speaking, having 3 more gears in the mix will sacrifice some power to friction, but the theory is ...


5

It sounds like you need a stronger differential. Might I suggest this design by Nazgarot: If you make two, you can build a big and sturdy subtractor like this (probably customizing the gear ratios to your requirements, the right gearing could also remove the need for a PF switch): Here's a video of it in action:


5

Yes, but only one color choice of light bluish gray is available in the default mode.


5

Here's a solution I found in Yoshihito Isogawa's LEGO Power Functions Idea Book Vol. 1 - Machines and Mechanisms: EDIT based on Eric's comment: And here's using the black piece from JohnnyB's tweak:


4

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 the ...


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

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:


4

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 bands ...


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