Friday, November 14, 2014

TBs TechChallenge, 2014 - Reverse 42034 (Quad Bike)

Here we're again for the 2014 edition of  the TechREVERSE Challenge, in collaboration with TLG. This is the sixth edition we do for this contest, this year covering one of the 1H2015 models.

As usual, the challenge will consist in the build reversal of one small LEGO Technic set. Among the several possibilities available we decided to go for a less obvious choice this time and hope you enjoy it.

But before we enter into more details, let me tell you which is the set chosen for the current TechREVERSE Challenge issue. It is the 42034 (Quad Bike).

And then the challenge TBs for you, is exactly this!
Reverse and build your own digital reproduction from the 42034 main model, based on the product pictures available so far.

Based on the successful experiment and results from the previous years, we decided once more to allow submissions made in any of the most common CAD tools in use by the FOLs, to model their LEGO creations (LDraw/MLCadLDD and SR 3D Builder). 
Hopefully the current situation with SR3D where support from Sergio is not available anymore, won't lead us into major problems.

Of course you may need to download and install any of these tools if you have not done it already before. Therefore some previous advices regarding LDraw installation may become handy.
Specially make sure you use the latest parts library available for the tool you're using. Otherwise it may negatively affect the ranking of your participation.

As for every contest, there must be some rules defined that will help us later to determine who's the winner. So please read them carefully.

Challenge Goal:
  • Reverse engineer and reproduce a digital model, from the Challenge proposed LEGO Technic set.
  • The reproduction should be precise (model complete assembly, parts list, colors and elements positioning).

Challenge Participation Rules:
  • Every contestant should submit his participation in the form of one single digital file, compatible with the latest version of one of the tools allowed in this contest (at contestant choice) - LDR, MPD, LXF or L3B.
    Hierarchical organization into sub-models is also allowed, for the tools supporting this.
  • The contestants are allowed to enter one single submission only (always the first one submitted).
  • Each contest submission must include one single model only.
  • Contestants must also include one render image from their model, with a minimum resolution of 800x600 pixels.
    It would be great if you have photo-realistic rendering skills, but not considered as criteria for the purpose of this contest evaluation.
  • Any eventual special elements in the model must be reproduced accordingly (e.g. flexible parts, shock absorbers, etc...). Reproduction should be as close as possible to the original.
  • All the submissions must be sent via e-mail, to the TBs mailbox setup for the purpose of this challenge, with indication of the applicant identification (full name and nickname if applicable), postal* and e-mail addresses.

    TBs TechREVERSE Challenge mailbox: challenge[at]

  • We believe there are no new elements in this model. If you think otherwise you should ignore the eventual new element(s) and leave the respective space empty in your CAD model.
    The same should apply if there is a part which is not available from LDraw or LDD libraries (although you get mismatch points if you think they are not available, but they actually are).
  • Due to the tremendous success of this challenge in the previous edition, where we got more than 30 participants, and the results evaluation was pushed until June... It was decided for a different evaluation method to limit potential damage, and which I had already unveiled before, a bit.
    What it means is that evaluation effort will be shared among the Challenge organization and the participants. After the official building instructions getting available online, each participant will be requested to evaluate the mismatches of is own participation, according to the usual criteria (as listed in the section below), and send them to our mailbox, within a certain defined period (lets say two weeks - to be confirmed later).
    Then we will pick a reasonable number of participants with the fewest mismatches, and do a full verification on their mismatches for consistency purposes and will find the winners this way.
    In the unlikely event of someone trying to cheat, it won't help him much, because as soon as it is detected the mismatch count will get higher than what it was claimed, we will move straight to next selected participant.
    The advantage of this approach is that we won't have all the huge effort to count the mismatches on every single participation, instead we share this effort with each participant by asking them to do pre-evaluation of their own submission.

Classification Criteria:
  • The winning participation will be the first submission sent, that exactly matches the LEGO official model subject of this challenge: model complete assembly, parts color, elements positioning and parts list.
  • If none of the submissions fill all the criteria above, it will be selected the first submitted one, that gets closer to the original, based the total mismatches counted.
  • There are different weights for each type of mismatch as a mean to differentiate the mismatches severity and improve the evaluation fairness.
    Each mismatch will sum a certain number of negative points (penalties) per occurrence, based on the respective mismatch type. The participation with less accounted penalties, wins!

    The penalties per mismatch type are:
    5 Points - Missing parts or subparts (so that you do not get tempted to avoid guessing on hidden parts just because it may lead to more mismatches than using wrong, extra or misplaced parts).
    3 Points - Wrong parts or subparts (includes friction/frictionless mismatches).
    3 Points - Extra parts or subparts.
    3 Points - Parts or subparts misplacement (including deviation and/or orientation).
    3 Points - Wrong color used for a part or subpart (if the element is visible in some of the pictures available).
    2 Points - Wrong color used for a part or subpart (if the element is not visible in any of the pictures available).
    1 Point - Every other eventual situation not covered above (e.g.: wrong spring strength, significant routing deviation from the original on flexible elements, etc.).
  • Classification (penalties sum) may not go through all the mismatches until the last one incurred. Once the amount gets too high and difficult to evaluate consistently, that it turns clear the participation won't get among the ones granted with a final prize.

  • All the submissions must be sent to the mailbox above indicated, in the next ten calendar days. Thus before the 24th of November 2014, 10:00 CET**.
  • The organization reserves the right to extend or shorten the submission period, if there is a reasonable justification (e.g. too few participants, leakage of the actual model or building instructions).
  • Final results are expected to be published until February 2015, but it may depend on the amount of submissions to the contest and bandwidth availability for the required verification work.


  • As usual the prizes will be some of the upcoming new LEGO Technic sets, signed by their respective designers. The details about these will be announced timely.

  • In the event of any eventual leak with further official details about this model, during the contest submission period, it may become a justification to close the submissions period anytime earlier.
  • Any eventual issues not foreseen in the contest rules, shall be evaluated and decided by the board of TBs editors.
  • The organization reserves the right to cancel the contest at anytime, if participation quality levels are not getting satisfactory.

Take part of the fun!

*) Your private data won't be published, or used for any other purpose other than this contest.
**) Use the link provided, to find the correspondent local time at your own Time Zone.


papluh said...

For the competition to be fair, I'd say the last image from the TRU site leak should be included. It's not searchable in their DB, but images still exists

TechnicBRICKs said...


Thanks for let us know. I didn't notice that image before. :P
Fortunately there are still enough details hidden to let some mismatches to come through.

I'll make another post with the prizes, and will add this photo too!

Philo said...

For those who need it, I just created this LDraw crude mockup of pull-back motor:

MajklSpajkl said...

Hi, It's great to run in TechREVERSE again. Since I use LDD and as it seems there is no pullback motor in LDD I'd like to ask if it is better to leave mockups out of the final model, or will those mockups be excluded from mismatches if the entry contains them?


TechnicBRICKs said...

Thanks Philo! You rock! :)

TechnicBRICKs said...


I prefer you do not use mockups. It will make verification work much easier. ;)

Philo said...

Oops, sorry! The part I made was 1 stud too high! Now corrected:

Philo said...

...and the real motor is now on LDraw Parts Tracker, thanks to my fellow parts author JC Tchang!
Don't forget to download all subparts...

papluh said...

Hmm, seems the set is already available at TRU

TechnicBRICKs said...

Just after the submission period closing... :D

papluh said...

Did you know about the release date from LEGO or it was just luck ?

TechnicBRICKs said...

Launch of some sets uses to happen at beginning of December.
Some big stores always put them on the shelves a few days earlier. :)

MajklSpajkl said...

Hi Fernando, now that also some photos of partlist are out on EB (a bit bad ones unfortunately, so it is hard to read all the numbers) I was wondering if you would give some extra pointers for the evaluation of our models. I'd like to know more about combining points or if one rule excludes the other etc.
For example: Ihave used two 7L black beams instead of 2 5L black beams - does it count as twice the wrong part (2x3) + twice part missing (2x5) or just wrong part or... In case if this part is also misplaced for one stud, also misplacement point shuld be added?
Thanks and best regards, miha


KKnaut said...

I counted the pieces in the inventory of the set and found only 147 pieces. The box said there were 148. Does the sticker sheet count as a piece?

TechnicBRICKs said...


Soon the BI for this model should be available online and we could do the exercise of let everyone count their one mismatches. :)

I just count one mismatch (if any) per each part placed in the model or missing in it.
Always the most severe penalty.
For instance, if you have one part misplaced (3 points) and also in the wrong color but it was not visible (2 points), I count just the misplacement, otherwise it could get easily too complicated.

You can also find some examples, from the files made available with the mismatch counting for the previous year's challenges.

papluh said...

I think this video review reveals most of the bricks and connections ;)

MajklSpajkl said...

It sure does, it reveals I messed up! :-) As it turns out not just those hidden parts in the fuel tank, also the front inclined beams were quite tricky... oh well, I guess we will count and see...

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