Injection marks on weird places

[merman]

TLG is continuously changing the place where mould/injection marks are located. 
This occurs especiallt with plates 

most recently, the mould marks of these parts have changed from the stud to the sides. 

https://img.bricklink.com/ItemImage/PN/11/4085d.png

https://img.bricklink.com/ItemImage/PN/86/44861.png

and with this part the mark has become much more prominent:

https://img.bricklink.com/ItemImage/PN/2/15712.png

 

does anyone know why this has changed? Isn’t a mark on a stud always preferable over a mark on a flat edge?

 

is it really that cheaper produce this way? It just looks really ugle and unnecessary and hopefully this is not a new development to cut costs  

 

 

 

 

 

Edited May 8, 2022 by merman

[dr_spock]

Redesigning a mold with different gate locations costs more than just making another copy of the worn out mold.  Maybe the molten plastic fills the mold better from the new gate locations? 

 

[JopieK]

They just might have made new moulds and then they would add improvements. From aesthetics viewpoint the stud is an obvious place, but it will affect the LEGO logo. Maybe also the flow of ABS would be better so overall part quality would increase. But I am not a industrial product designer so maybe those are the ones that can better answer it.

(@dr_spock beat me to it, but we both think the same...)

[MAB]

It may also be that they can produce more parts per cycle by changing the orientation of the parts within the new mould.

[Mylenium]

On 5/8/2022 at 3:24 PM, merman said:

Isn’t a mark on a stud always preferable over a mark on a flat edge?

Not really. Your statement wouldn't even make much sense considering that lately e.g. several tile elements had just the opposite and had their injection points moved from the edges to the underside so they're smooth all the way round.

On 5/8/2022 at 3:24 PM, merman said:

does anyone know why this has changed?

One could sound all smart and make up a million reasons like optimized flow of the material, less internal warping/ tension and so on, but perhaps the simple truth is that a "flat" placement may increase yield. You can place and design the injection sprue/ tree differently, you may need less reservoirs to even out the internal pressure and flow, placement of clippers and auto-clipping may work better. If they can squeeze a handful more elements into a mold block and produce less waste, it makes a huge difference for a company as big as LEGO. That could easily accumulate to thousands of dollars saved in a production run. The cost of a mold itself  doesn't change much, though. There's always a baseline amount you can't get rid of. After all, you need a block of metal that has all sorts of connections for cooling/ pre-heating, vacuum, ejector pins and whatnot.

Mylenium

Edited May 11, 2022 by Mylenium