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:
Hooray, I get to answer a question!
This is not a piece for launching missiles. It's actually part of an old steering assembly from some late 80s and 90s Technic sets.
Here's what the whole thing looks like:
And a view of the piece in question:
And an example of how it is meant to be used:
The teeth on the outside of the piece help lock it into one of ...
The studless have SEVERAL advantages over the studded design especially when you want to include moving parts. Just the clearances between connections is important. Sariel sums it up in his book well. He says there are advantages to both systems (stud-full, for example, are more rigid) but the fact that the stud-less look more realistic and, of course, the ...
The regular connector have simple angles which are multiples of 22.5°. #4 is 45°, #3 is 22.5° and #5 is 67.5°. That's pretty boring stuff, but there you go.
The 53.5 angle isn't as bizarre as you would think and there's a very good reason for it (and less boring to me, but YMMV).
That reason is that it forms a Pythagorean triangle, and specifically the ...
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 ...
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:
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 current Mindstorms sets are completely Technic orientated and use the Technic pins (i.e. [part:3673:7]) to connect to the newer Technic Beams (i.e. [part:32316:7]) as well as the original Technic Bricks (i.e. [part:3894:7])
The various different size pins and axles are the way to interchange between these.
There are a number of Lego Pneumatic sets with airtight tubes, valves and switches which could be put into use with fluids. One is 9641, Pneumatics Add-On Set.
Bear in mind that the pneumatics sets can command a much higer price than those sets with a similar number of parts, and buying individual pieces can also get expensive. Have a look at BrickLink to ...
You probably could use this, which looks exactly like it's the missing part of your puzzle:
You'll be interested to know that this part has intitially been proposed by the first four fans (MUPs, for LEGO Mindstorms Users Panel) working on the very first NXT kit and regularly ran into the same problem as yours. A lot of Technic fans now name the part after ...
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 think the most important aspect is a matter of geometry.
With studded beams, you're constrained by the form factor of the regular LEGO brick, which isn't a cube but a 5:5:6 cuboid. This means that every time you need to change the orientation of things, you'll have to think about how you're going to do it, and use plates and whatnot between beams. It's ...
If you're after a simple collapsible solution to reach those items just out of reach, you can start with the following setup:
You can extend this for quite some way, and use longer bricks or beams throughout if you wish.
To finish it off, I'd use a couple of longer bricks with some additional plates on the end to act as fingers, and add some handles (via ...
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 ...
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.
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 ...
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: ...
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 ...
According to LEGO, this type of connection is illegal, since the pin is stressed when connected to an anti-stud and eventually deforms.
People's MOCs do not follow same policy as TLG does. So you may encounter illegal connections from time to time. Pins are also cheap and usually owned in high numbers, so nobody's really bothered if one gets deformed.
It appears from the photo that there may be some "blooming" where the axles have changed color? You say you rinsed them, but I wonder if you noticed whether the axles felt oily or sticky at all beforehand?
This would be consistent with the kind of deterioration that is common with Polyvinyl Chloride (PVC), a kind of plastic that was once common in toy ...
I've found a solution that's actually pretty easy, but took some time to try out because I don't have the parts I need at hand.
Input from motor(s).
A differential to split up the input-movement to two shafts. Since I don't have a Technic Gear Differential at hand I had to built my own for the test.
One of the differential-outputs becomes our "...
Here are the two things that I would recommend:
Get yourself a big set if you have the budget for it. These will have a large variety of pieces and once you've built the models from the instructions you'll have a good understanding of a lot of different building techniques.
Watch eBay or similar sites for large lots of Technic parts by the pound. These can ...
There are several editors which are based on the open LDraw part database.
I believe that the most popular are MLCAD and LeoCAD. I personally use LDD, so I can't speak to the quality of the instruction generation from these tools, but they do at least offer the ability to create instructions.
LeoCAD is probably your best bet for doing animations, and it is ...
Despite what it superficially looks like in (for example) Sariel's build videos, having a big pile of parts spread across the table is not the fastest way. Pour the contents of the smaller bags into containers (I use old plastic take-away containers). That way you are looking through a container of blue 3 long pins and red 2-long axles for a 2-long axle, ...