According to Brickset, these parts have always been made of polyethylene, the only difference is that some of the material is plant-based since the Plants from Plants initiative.
Can you tell the difference?
No! They look, feel, smell and work just like 'regular' botanical elements. This is because, chemically, they are the same. You can safely mix them ...
LEGO baseplates are made from ABS plastic, like most of the opaque rigid plastic LEGO elements since 1970. ABS is a thermoplastic consisting of a styrene monomer with the addition of an acrylonitrile momomer and a butadiene monomer. There is no PVC or vinyl present.
I suggest reviewing this thread for more on laser-cutting ABS. It is not a trivial matter to ...
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.
Quorneng's answer is spot on, even bricks that were from the same set might have been made from differing batches of a particular color and slight variances will produce differing colors. Purple is the most notorious Lego color for having a great deal of variance between bricks, and red is not surprisingly, also inconsistent at times.
To add to the mix, ...
This is a partial answer (or theory).
The moulds for most of the basic bricks have been changed over the years to use less plastic while (hopefully) retaining clutch.
2 x N bricks were given thinner walls with 'notches' for the studs. This may have slightly weakened clutch power.
1 x N bricks (and some plates) were given holes through the bottom ...
Most LEGO and DUPLO parts are made from ABS plastic. ABS does not contain BPA. Here's a statement from LEGO about the safety of ABS:
The majority of LEGO elements are made from ABS plastic (Acrylonitrile Butadiene Styrene), a high-quality plastic that meets our extensive list of safety and quality specifications. The colors and materials in ABS plastic do ...
For starters, having that as a production error is completely impossible, given the industrial precision of our beloved bricks. The LEGO group has been incredibly careful for decades about the tolerance of their bricks' dimensions:
You can read this WIRED article where the author compares old and new bricks' dimensions (TL;DR: they have been making really ...
LEGO switched from cellulose acetate (CA) plastic to ABS plastic in 1963. They continued to distribute CA pieces in sets until their existing supply was exhausted, so during the transition beginning in 1963 both types of pieces were sold in sets. In North America, LEGO pieces were manufactured beginning in 1961 under license by Samsonite, which continued to ...
I am also going to recommend Technic as the stronger support option, but I would make the case out of "normal" Lego, and then implement 2 Technic rectangular "rings" around the case at the place of your pillars, joined at the top and bottom (on the top the joint could form the handle). Make these rings or braces by overlapping Technic pieces and joining them ...
This assembly of pieces will not tickle, so let's dive in:
First, the teeth are placed in reverse of each other so the foot and
all that weight is forced to rock on the two little pointed tips.
Second, the white circular base is wide enough to minimize rolling of
the piece as experienced with a 2x2 brick, where the weight of a
person would force the piece ...
The colour of virtually all plastics, like paint, is an 'added' pigment so it is difficult to maintain exactly the same colour.
As others have pointed out some pigments are more susceptible to the effect of sunlight than others - red goes pale - white goes yellow.
There are several reasons for this:
There isn't just one formula for the ABS plastic that is used in
LEGO. There are actually quite a few. Depending on the color,
translucency, and function, the mix of materials will vary.
Translucent pieces are quite a bit harder and more rigid than other
Lego bricks. Mini-figure accessories tend to be quite a bit softer
Generally LEGO Technic structures (pins and beams with holes) tend to be lighter and stronger as System structures (classic bricks). The generally accepted best practice among amateur and professional LEGO builders is to have a light and strong internal structure (either Technic or other materials, like wood or steel) that can then be decorated on the ...
The LEGO Group has already created clear sustainability goals.
TLG is currently investing money to try to find sustainable and non-petroleum based ways to design LEGO bricks. Here's some info about the new Sustainable Materials Center that TLG is working on:
It sounds like ...
The clear PC arms are more brittle, however you should be able to replace them at least once, since the torso you are placing it into is ABS - so there is a bit of a give/flexibility on that side.
One thing to be careful of, is when you take out the PC arms (and when you put them in a new torso), do not hold the arms by the hands! This will put pressure on ...
The LEGO Group has been extremely careful about the formulation of all of the plastic parts they manufacture.
I do not believe they ever used lead in any of their parts. Decades ago they removed cadmium from the yellow pigments.
I have never found that isopropyl alcohol will soften the plastic used for Lego bricks.
What will soften Lego bricks is hot water. ...
As 62Bricks has said, this can be an art.
Based on my experience (in the UK):
CA bricks tend to have less clutch (stickiness to other bricks) than ABS bricks. I'm not sure if this is because they are more prone to wear, because they tend to warp or just because they're old and worn out. Nevertheless, some of my CA bricks are so non-grippy that they're all ...
Silicone does not appear to be safe with ABS plastic
This sounded like a good idea to me since silicone works well in other extreme circumstances like baking, but the quick research I've done says this is not so smart. I found two general references for ABS compatibility:
Plastics International Plastic Compatibility Chart
Kelco's ABS compatiblity chart
While I can't speak of the handling of these parts, the possibility of receiving official replacement parts from TLG is surely zero. That leaves us only the second-hand market, which fortunately offers genuine LEGO replacement pieces, sometimes even in brand new condition. Note though, that even though the brittleness problem might stem from lots of play or ...
Any metallic or metal coated parts (spoon, aluminium foil, pen) should be usable with a contemporary touchscreen, although proper touch recognition still requires a human (or an equivalent capacitor) to touch the conductive surface. Therefore theoretically any of these official LEGO parts with exposed metallic surfaces (or similar ones) should function, ...
To sort ABS bricks from CA bricks can sometimes be difficult. What helps is they SOUND differently. An ABS brick emits a higher pitched sound when dropped than a CA brick which sounds more like a "thud". So if you are not sure, drop the brick and the sound will tell you what it is.
Just like in the other question, I would recommend a Technic frame with more depth than your original idea and some plating on top of it. This project nicely illustrates how to build stable Technic structures using beams in triangle configurations.
The first picture is from Elector,
the second is kai robot.
They are both robotic kits from Iran, you can order kits from their site.
If you are looking for a Lego solution,
the Lego Eduction program has robotic kits like Mindstorm and WeDo, or you could look at Lego Boost
I may found a hint onto what's going on with old elements made of ABS on sister website - Chemistry.SE. That question discuss other problem with ABS plastic - brittleness, however answer provide some interesting facts:
The original ABS substance is a copolymer made of acrylonitrile,
butadiene and styrene. It is rather hard and brittle. To make it