Shopping at LEGO or Amazon?
Please use our links: LEGO.com Amazon
As an Amazon Associate we earn from qualifying purchases.

When does LEGO use hollow studs vs solid studs, and why?

Mr_HobblesMr_Hobbles San FranciscoMember Posts: 277
So I was looking at some parts on my desk here at work, namely the Boost Move Hub, and the WeDo 2.0 Hub, and I noticed that both of them have some solid studs, and some hollow studs. See this picture.

How does LEGO decide when to use hollow studs vs solid studs? I perhaps understand different parts having different types of studs, as they'd maybe be designed at different times and by different people. But the hub itself has both types of studs on it - the same part.

Is there a technical reason for when LEGO decides to use a certain type of stud?



FowlerBrickssnowhitie

Comments

  • omniumomnium Brickenham, UKMember Posts: 768
    I have no idea. But one thing I notice with the hub that has a mixture of stud types: the "System" sections have solid studs, and the "Techinic" sections have hollow studs. Which reflects how System and Technic bricks are made.
    catwrangler
  • Mr_HobblesMr_Hobbles San FranciscoMember Posts: 277
    Those reasons seem reasonable! Though it begs the question, why does the stud need to be hollow at all? Clutch power reasons? Cutting down on plastic usage...?
  • OldfanOldfan Chicagoland, IL, USAMember Posts: 621

    Some of this depends on the molded part: when injection molding, if at all possible you want to keep the thickness of all the different features of the part ("wall thickness") consistent everywhere on the part.  If one feature (e.g. the side of the brick) is 5mm thick and another feature (e.g. the stud) is 10mm thick, it can be difficult to fill the molding cavity and cool the plastic evenly during molding and you might end up with warping, "sinks" (depressions in the plastic surface), and other physical irregularities.  I've noticed that some solid-stud parts actually are hollow on the underside to try and achieve this.

    Another good reason for hollow studs is the ability to insert the end of a bar into the stud to achieve a certain look during a build...

    catwranglersnowhitie
  • 560Heliport560Heliport Twin Cities, MN, USAMember Posts: 878
    I like your "easier to mold" better than my "uses less plastic" idea! I'm looking at the LEGO I have here at work (#30525 The Guardians' Ship and #75165 Imperial Trooper Battle Pack) and it seems all studs are hollow on either the "top" or "bottom". I'm sure there's some exceptions, but it seems pretty consistent.
  • omniumomnium Brickenham, UKMember Posts: 768
    edited August 2018
    SNOT bricks have hollow studs on the sides...

    So perhaps the hollow is to do with what is behind/underneath the stud? i.e., if it's a hollow thing, like a plate or brick, it have a covered over stud. And If it's a solid thing, like the back of a SNOT bracket or a Technic brick with axle holes, it's hollow.

    That doesn't explain jumper plates, mind you.
  • Baby_YodaBaby_Yoda The world's backsideMember Posts: 1,229
    ^ Because the stud on a jumper plate is situated over the tube on the bottom of the part, whereas on a regular plate there's nothing underneath it so there's room to make it hollow from the bottom.
  • AleyditaAleydita BelgiumMember Posts: 796
    The 'easier to mould' reason is the explanation I was given years ago - almost all studs are hollow, either below (preferable) or on top if that's not possible.
  • LyichirLyichir United StatesMember Posts: 727
    One factor I've seen mentioned is that when designing parts is that solid studs are often considered preferable for them (especially compared to completely open studs like those on 1x1 round bricks), because even though they offer less connectivity they display the logo more prominently.

    Of course, that's just one consideration—many other factors are applied in that decision-making process as well, like a part's similarities or differences with existing part families.
  • RecceRecce Tiny Little Red DotMember Posts: 897
    Is it possible TLG limited the hollow stud parts due to other brick companies already patented the designs? 

    I would think that having all bricks with hollow studs gave much more flexibility than solid ones.

    Also, as mentioned above branding could be another major factor in favouring the solid studs with the Lego word prominently exposed in each and every stud. 
  • AstrobricksAstrobricks Minnesota, USMember Posts: 2,472
    Aleydita said:
    The 'easier to mould' reason is the explanation I was given years ago - almost all studs are hollow, either below (preferable) or on top if that's not possible.
    I’m pretty sure this is the main reason. Not only do you need to be able to get plastic into all areas of the mold evenly, you also need to be able to open it cleanly afterward.
  • CCCCCC UKMember Posts: 17,815
    The open studs are for attracting and containing the maximum amount of dust and dirt possible to annoy AFOLs.

    TheOriginalSimonBSwitchfoot55omniumOldfangmonkey76Baby_YodaRakul
  • Pitfall69Pitfall69 0 miles to Legoboy's houseMember Posts: 11,375
    Baby_Yoda said:
    ^ Because the stud on a jumper plate is situated over the tube on the bottom of the part, whereas on a regular plate there's nothing underneath it so there's room to make it hollow from the bottom.
    Aren't the new jumper plates hollow? There isn't a tube underneath.
  • Baby_YodaBaby_Yoda The world's backsideMember Posts: 1,229
    ^...Consistency?
  • iliketoastiliketoast AustraliaMember Posts: 260
    Don’t jumper plates have slightly lower clutch?
Sign In or Register to comment.

Shopping at LEGO.com or Amazon?

Please use our links: LEGO.com Amazon

Recent discussions Categories Privacy Policy

Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Brickset.com is a participant in the Amazon Services LLC Associates Program, the Amazon.com.ca, Inc. Associates Program and the Amazon EU Associates Programme, which are affiliate advertising programs designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.

As an Amazon Associate we earn from qualifying purchases.