There's a brick-built spiral staircase in the Pet Shop:
That's definitely the most common way to do it. You just build up around a central point. This can be expanded to use longer or wider steps:
You can also use 2x2 turntables if you need more strength and/or larger stairs:
Your second guess was correct. It's not just a wrench. It's listed as a Screwdriver/spanner on Lego.com:
This part was also included in several sets in the Games line as a human tool to remove tiles from the dice. It's unclear (at least to me) whether this part was intended to be used for tile removal when it was introduced in 1979. Here's an example from ...
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.
Is it possible that you are thinking of this goblet (2343)?
This part was fairly common, and it was introduced around 1985, so it was probably in your collection.
1x1 round plates attach securely to the top as shown in this lamp from the Pet Shop:
🎶 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 ...
The green parts are great to make a green smooth field, which is kinda obvious. Landscaping is one usage, and if you find it too uniform, don't forget you can cover some areas with additionnal hills or whatever. The Technic hole in there can come handy as you can easily attach something in it. Since it'll rotate freely, your added decoration can even be ...
According to LEGO, it's the BrickHeadz icon with the series number.
He also stands on a buildable baseplate with series number and BrickHeadz icon for easy display -- Batman Brickheadz LEGO Shop page
If they release another series of Brickheadz, those sets will probably have a similar piece with a "2" on it.
In the case of 87609, the piece was first used in 2010 as part of the grill/bumper assembly for vehicles that were the standard 6 studs wide. Its length would appear to be a result of its original purpose. Its width also allows for attaching two rows of detail:
99206 showed up first in 2012. Its design allows for a more compact construction in situations ...
Just today I tried to use it quite successfully as an alternative to suspension springs. Right now I don't have it assembled so I can't post a screenshot, but the idea is to wind up the pullback motor then attach it to your construction with a cross axis from one side and beams from another and limit its moving with some details. If you are interested in how ...
My guess would be that they wanted to include one in more sets; so they made a smaller (cheaper) version and took the opportunity to add functionalities, such as the technic axle remover or the flat end for removing tiles easily. If I'm not mistaken, this version works on jumper plates too; which wasn't the case with the old one.
Yoshihito Isogawa made clock mechanisms from it (well... tic-tac generators) http://www.isogawastudio.co.jp/legostudio/modelgallery_model/b077.html
Majorna created a "programmable" pull back racer http://www.eurobricks.com/forum/index.php?showtopic=69748&#entry1744425
Using a cut-pipe into a clip-with-tube will let you build a secure and precise angle.
If you have a solid brick behind the headlight bricks you can fix the angle by cutting the pipe at the right length.
Great question. It sounds like you are building a fairly large ship. If the scale is large enough, brick-built sails can look quite nice. You can add shape, contour, and texture using various building techniques.
If you want to keep things simple, you could just use a single layer of bricks as was done in this basic sailboat model that was an in-store ...
The 1x1 brick is both small enough to mean that you get edges no matter which way up it is, and has all the sharp edges and corners of the 2x2 brick, just packed into a smaller, more evil form.
That naturally leads to the headlight block, which has all the same features, but, if you are unfortunate, can also attack with the lip on the bottom.
Minifig hands, officially, are not to be removed. Lego doesn't make many accessories that fit the arms of the minifigs. The arm is slightly larger than the standard bar piece and so normal claw-shaped attachments don't fit. The minifig handcuff piece, which does fit over the wrist, is larger than the standard claw pieces.
You'll need to look to third-party ...
I still have cups and 1x1 round bricks from the late 70's and I can ensure you these were never brickable like you suggest.
In the 80's, another popular build from Lego was composed of a transparent cup on top of a transparent minifig head. Here is a colored example of that build.
You can see the inventory of the opera house on Brickset.
The majority of the roof pieces you seem to be concerned about are these bow pieces, of which you get 34 pairs and one extra left piece.
These pieces are fairly common and are used typically in cars, boats, planes, spacecraft, and other aerodynamic structures, as well as building roofs, robots, and ...
It's not deep enough, but depending on what the model is for it might be sufficient: a 2x1 brick with no center pin is almost exactly the right width/height for a USB plug. These are easy to find in transparent colours but solid colours exist as well.
At a larger scale, a similar hole that includes an indent that can accept circular connectors, preferably 3-brick long for anchoring, for a true connection. But at that size, it would be roughly 3.2 times the size of a typical laptop.
For a tiny model, just do a 2 x 1/3 x 1 brick hole, into which a no-studs plate can be slipped.
If you are going for an ...
Once I built a hand-powered semi-automated screwdriver toy for kids. They needed to "charge it" first by rotating a gear and then push a button to release power. Then they could apply it to a crane or other models.