A top complaint I see about clone brands is the quality: specifically the flimsiness of the plastic, premature discoloration, or poor fitting with either other bricks of the same brand or with Lego. I've never seen a quantified study of the various clones though. I consider the poor fitting issue the worst issue. How hard/expensive would it be to build/buy a device to measure the force of attaching and detaching plates and bricks?

My anecdotal experience: I have Lego, Sluban, Cobi, Xingbao(Lepin), and 2 other brands that I'm not sure of the source. Among these, only the "Technique" axles and axle holes from one of the unknown brands are incompatible with Lego: Lego's axles are bigger so don't fit in the clone's axle holes, and the clone's axles have no friction in Lego's axle holes. But having numbers to post in an article and point at would be nice.

  • One problem with this would be around consistency - certainly in an older MegaBlocks set I had it came with a large number of "spare" 1x1 studs, probably because they knew some of them wouldn't clutch on to a stud properly. Commented Jun 19, 2019 at 15:03
  • That's true. I really would have to test multiple instances of each type. But at that point the permutations really explode. With 6 brands, there are 30 permutations per brick type (e.g. 2x2 brick). If I measure each pairing 3 times, that's 90 measurements. If I measure 3 different instances of each brick, that's 270 measurements (and that's assuming the instances are tested as pairs instead of with every other instance). At that point it would make more sense to just get a micrometer and measure each brick exactly... Commented Jun 19, 2019 at 15:53
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    I've gotten a couple more brands since this post: Enlighten and MegaConstrux. I've done some bigger builds too using multiple clones together. I've discovered that the clutch power is really a symptom of secondary importance. The main problem is that when combining large pieces (especially plates) with slightly different tolerances will cause the larger piece to bend ever so slightly. But this adds up over a large build. And it's caused by same issue: the dimensions aren't exactly the same as Lego. So I'm still inclined to get a micrometer and do some measurements. Commented Jul 17, 2019 at 16:04

1 Answer 1


How hard/expensive would it be to build/buy a device to measure the force of attaching and detaching plates and bricks?

Thankfully we don't need to think too hard on that, as pcantin has already built a similar device, admittedly built for measuring the repetitions it takes for a brick to lose its clutch power. But it should not be too hard or expensive to modify that design to include something that can measure the exact forces involved. Or it maybe possible to measure the amount of current required by the servo during attaching or detaching and to infer the involved forces from that and thus solve the problem witout requiring any major hardware alterations.

But if your goal is to compare a number of various bricks, I'd recommend a different route. Attach a number of nominally same bricks (i.e. a bunch of 2x4 bricks for example) together in a stack, then pull the two end bricks apart. This way you are applying some force to the top and bottom bricks which gets transmitted across all intermittent bricks. By increasing the applied force the two bricks with the weakest bind will separate first, be they anywhere in the stack. This is akin to finding the weakest link in a chain by pulling the end links apart to see which link break first.

Of course this will only tell us which connection (consisting of a brick's stud-side and another brick's antistud-side) has the weakest clutch power, but by repeating the same test with varied composition (all bricks from manufacturer A, the same bricks in another order, bricks from A mixed with bricks from B, bricks from A on the top and from B on the bottom, etc.) with some planning and measuring it should be possible to establish intra-manufacturer and inter-manufacturer variations in binding force.

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    Yes I did see that. Quite cool. :) It probably would be relatively easy to modify to measure force, but given the number of permutations I want to test, as you imply, it would be tedious. I'm not sure about the stack of various brands to find the weakest link. Seems like a pretty confusing way to go about it if there are 6 brands: instead of keeping track of which pairs I've tested, I'd have to track which permutations of the full set I've tested. Commented Jun 19, 2019 at 15:47
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    @MattChambers I'd definitely advise against using 6 brands at once, rather use a stack made of two A brand bricks and two B ones to see which bond is the weakest: AA, BB or AB. Then swap out all Bs for Cs, after that all As for Ds and so on. But seeing that a major factor of brick quality is consistence, even stacks of pure A bricks should be tested to see if mixing up the positions of individual elements in the stack affect the result.
    – zovits
    Commented Jun 19, 2019 at 17:17
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    That's a much better idea. I can use that to find the worst offender brick, measure it, then I'll have something to benchmark all the other bricks against (probably in terms relative to the official Lego dimensions). Commented Jun 20, 2019 at 19:46

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