The presentation that senior Lego designer Jamie Berard held at Brickcon 2006 and that spawned the entire legal vs illegal discussion can be found here:
The particular case you ask for is discussed in slides 9 and 10:
Over the years the LEGO group has made a number of different springs, dampers and suspension components. The most widely known ones are the springs in the 731 series, such as the above mentioned 731c04 (Hard Spring) and its cousins 731c05 (Normal Spring) and 731c06 (Soft Spring), but there are other more specialized springs as well, such as 32181 (which ...
The axle is misaligned by half a stud, so an obvious approach to this problem is offset your motor by half a stud.
The technique of offsetting bricks by half a stud is known as AZMEP (from the german "aus zwei mach eins Plättchen", meaning offset of half a stud), which is a specific case of the SNIR (Studs Not In a Row) technique.
As it has been ...
As it turns out, the answer is yes! Even though the wings are flat and can't generate much lift, I was able to get up to about 15ft of distance on a 10ft drop.
click to watch the video
Here's how I did it:
First, you're going to need 2 of the set, or at-least two copies of the sails and some common Technic pieces. This is because the sails in the set are two ...
I actually managed to find the exact set while refining the question. It's set 744, released in 1980.
Here are the reasons why the research I did prior to writing the question didn't lead anywhere:
The yellow motor does not show up when searching parts on BrickLink. It's probably because on the list of set 744 parts, it has a note saying "Part colour ...
There are more than one set with such characteristics. While first four are from 20th century, I've included them anyway, since they are well-known and include characteristics you are interested in.
Let's begin with 8860 - Car Chassis from 1980. This model has steering, 4-cylinder engine, 3 speed transmission, adjustable seats, rear suspension, ...
It sounds like you're trying to implement a fairly simple bell mechanism such as this one:
You can certainly do this using some string and the pulley element that you mentioned.
I'd recommend tying the string to one of the holes in the pulley. Something like this worked reasonably well for me:
Here it is in action:
You'll likely want to do something to ...
Push the Technic pin in a beam hole, then insert a rod (antenna or minifig tool handle) into the hole in the pin from the other side. The rod will prevent the "lips" of the pin from closing in, therefore preventing the pin from leaving the beam. Then you can pull on anything attached to the other end of the pin.
This example below shows the removal of a pin ...
With a few Power Functions elements and a pair of propellers, I was able to build a motorized boat similar to the alternate model.
1x: 8881 Power Functions Battery Box
2x: 8883 Power Functions M-Motor
1x: 8884 Power Functions IR Receiver
1x: 8885 Power Functions IR Remote Control
2x: 30332 Propeller 3 Blade 9 Diameter
See it in action!
click to watch the ...
With some Power Functions elements and a few extra pieces, it's pretty easy to turn the Rally Car into an RC car.
Here's a quick demo video of my design in action.
And here are the instructions I made for it.
Required extra pieces
First you are going to need some extra pieces:
1x - Servo Motor
1x - IR Receiver
1x - Battery Box
1x - L-...
The easiest way to do this would be to use a motor with a high speed (or gear up a lower speed motor) and then attach one of the larger propeller elements to it. You can probably build a custom prop, but it might be challenging to build something with the proper blade angle while keeping it light and strong enough to not break apart when rotating quickly.
YES! Philippe Hurbain (Philo) has put together a great and very detailed write-up on those and many other LEGO 9V electric motors.
You can find it here: LEGO 9V Technic Motors compared characteristics
Your current draw for that specific motor @ 9V is:
No load: 65mA
Loaded (3.6 N.cm): 310mA
Loaded (6.0 N.cm): 480mA
Stalled (11 N....
I usually attach it to a Technic beam, then put something to fill the hole so it can't squeeze together and come out, to give a handle.
The flexible rods tend to be a nice options for filling the hole, the older ones may be a bit better, but I've had success with other pieces that fit minifig hands.
Once you have the blue pin attached to the beam instead ...
Put two plates between each layer of Technic bricks and the holes will align.
This technique was used commonly in studded Technic sets. Here's a page from the instructions for 8042 where you can see this used in several different places:
If it's your own creation, you should be able to adapt your model to fit the rack you have. One tricky problem I can see is if your construction is built as most studless models are nowadays and features uneven dimensions - which means a 7 rack is indeed easier than a 8.
You can of course build something around the old 1x4 rack place but it might get ...
That is 4 separate parts. They can be disassembled, but they are somewhat fragile. The ends are part 6644 Technic Flex Cable End - Ball Connection with Cage:
The middle section is made up of a length rigid hose with a flex cable inside.
The cable end includes a hinged door that allows flex system hose to be freely inserted or ...
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.
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 ...
I don't have this set, but used 8421 as a test. This set is also released in 2005.
Looking at the PDF you see the same color scheme of the axles, were the black appear to be gray and vice versa
When looking at the instruction manual
You see the normal colors, so indeed your set came with the normal colors and due to some bad scanning and compression the ...
In addition to Sariel's excellent book, I'd suggest Yoshihito Isogawa's "Tora no Maki" (Book of secrets) downloadable PDF book, and his Ideas books in print. All are full of clever mechanisms, easy to reproduce and integrate into bigger constructions.
In general, this sort of connection is illegal, but I think that it works fine with a Travis brick. Technic pins must be "in click" in a model, or the pins will be held in compression and can be damaged over time.
Here's a slide from Jamie Barard's classic "Stressing the Elements" presentation that explain the need to have Technic pins in click:
And here's ...
What you're looking for is reciprocal motion, or to convert rotation motion into linear motion (and then back to a limited rotation).
Building out the key parts of the fan head you have the following setup (using fairly standard technic pieces:
Drive the smaller cog normally, this will rotate 360° as normal.
The driving rod will only move as far as the ...
🎶 First three from what we can see...🎶
Part: 4735 Bar 1 x 3 with Clip and Stud Receptacle (Robot Arm).
Part 2958 Technic, Disk 3 x 3.
Part: 75c03 Hose, Rigid 3mm D. 3L / 2.4cm.
🎶Last two hidden from view...🎶
4 & 5. Part: 4085d Plate, Modified 1 x 1 with Clip Vertical - Type 4
(thick open O clip).
I can't see, but I can imagine two crossed ...