Wednesday, January 19, 2011

TBs TechTalk 04 - Designing set 8043, Motorized Excavator (Part III)

[Part I], [Part II]

Today the last part of the interview with Anders Gasendal (AG) and Ricco Krog (RK), about the design of the 8043 Motorized Excavator.
And so it continues...

TBs: How many different prototypes did the excavator go through before the final design was chosen? And how much has it changed from the original concept model?

AG: It’s a little hard to answer clear, because some prototypes were developed only partly to improve certain parts. These parts were then later on build in a model with all improvements incorporated. Giving a rough estimate, at least 30 significantly different models has been developed. But in between them, a lot of smaller prototypes on parts of the model were developed.

These are a couple of never seen pictures from the very first 8043 Motorized Excavator model.* On the left: The very first sketch of the excavator and what convinced the Design team members that such a model was possible to develop as product. On the right: The first prototype of the idea with the way the remote controlled gearbox works.

TBs: Is there any element you'd like to exist, that would have helped in the design of the Excavator? If so, how would it improve the model?

AG: It would have been nice to make a specific shovel for this model, but it would only have helped the A model, then we would have to make another B-model, so its always a compromise when you are designing LEGO models, whether it’s System or Technic, keeping elements in a system to make them useful for many different models.

TBs: What limitations do you have regarding the design of new parts? Is there a maximum number of new parts per year or is there a set budget? For instance you have used the same bucket usually used on the large Technic Front Loaders. Did you choose a B-model that justifies this choice intentionally and thus limiting the development costs of a new bucket, more suitable for large Excavators?

RK: Every year during our concept faze we come up with a long list of new possible elements; we then evaluate which elements would be best for the models we are launching in that year. These elements are then presented to the management and they hopefully approve them.

Regarding the bucket, you are absolutely right, we did choose a B-model that justifies using a bucket from a front loader. I think this was the best compromise, had we done an excavator bucket we would have had trouble finding a right B-model.

TBs: When/how do you decide which color a specific model is going to have? Who decides it?

RK: I try to find a color that fits a specific model the best and a color that you would typically find on the same model in the “real World”. The decision it made before we test the concept models. As the Design Manager it’s my decision what color a model has.

TBs: In these videos [1, 2] Markus described the design process behind the 8275 Motorized Bulldozer. This is also the process we often hear about, where kids are involved in tests and where the models are stressed to the limits. He also describes the LEGO Technic design principles of "Authenticity, Functionality, and Challenging Building." We are pretty sure that TLG continues to enforce these principles, the development process and even fosters their continuous improvement. But… how come? Was the Functionality of the 8043 and elements durability properly tested? Are you intrigued that the LA issue off was not noticed during in-house tests. What happened to TLG's own design review procedures? Did the huge complexity of this model somehow cause project delays, and lead you to lower your guard on some basic development principles?

RK: Since the 8275 Motorized Bulldozer, our process has been improved even further. Our model quality is of highest importance for us, we do extensive testing on all our models. The 8043 Motorized Bulldozer is no exception to this. When we were contacted by our consumer service about the problem, it defiantly came as a surprise as none of our models had shown any problems during the tests. I immediately took contact to a couple of fans; they were very helpful and borrowed us their models to look into. When playing with these models, it was clear that the actuators had an internal friction problem which we had not seen before. We right away started up the process of producing new actuators that did not have this friction problem. The new actuators have now been shipped out to everyone that has contacted the LEGO® consumer Service. All sets with the faulty actuators are no longer on the market. The LEGO Technic team is very sorry for any inconvenience this problem has caused.

TBs: Do you have an estimate about what percentage of those that buy Technic are AFOLs? How much influence does the AFOL community actually have on what you guys bring out?

RK: Our estimate is 10% to 15% but mainly in the higher price points. The AFOL community have a lot of influence as we are listening to all the discussions and comments on the different forums. We try to take as much in consideration as possible and at the same time develop models that are cool and attractive to our main target group; the 7 to 16 years old kids.

TBs: Is there anything you can tell us at this moment about what we can expect for next year (besides obviously that we're going to get plenty of good stuff)?

Unfortunately, Ricco did not answer this question! Perhaps he missed it...

Thank you very much for your time Anders and Ricco, we wish you many great ideas for the 2012 sets and beyond. And thank you for the great Excavator! Also congratulations to the entire team, who have brought so many other great sets in 2010.

*) Images published with the authorization of the LEGO Group.
If you use these images, please always link to this post, so that the contextual information isn't lost.


Barman said...

Nice to read about everything about this great set.
I still don't understand that the problem with the LA's just are in this set. In my case it's the same with the 8265 Front Loader. Raising the boom is tough. When I built in the M-motor it had difficulties to raise the boom as well.
I think that when the old LA are combined they work against each other instead of working together. Because i excepted this problem I moved on without complaining to Lego-service.
When the 8043 came out and other people had the same problems, I called Lego-service as well.

My own excavator also uses LA's to controle the arm.
Because I use 1 LA for raising the boom it moves smoothly. The boom is much heavier that the one in the 8043. I use a small down gearing to cope with the weight of the boom. It doesn't work fast, but it runs very smooth, as you can see in the video.
So I think the problem isn't in the many gears and cross-axle length, but the 2 LA.


Tobbe Arnesson said...

Oooh, Orange would have been sweeet! :-O But yellow is fine too!

Thanks for the articles, love to see more of these in the future!

santi said...

My favourite part is seeing pictures of the prototypes. I'd love to see more of these! :)

santi said...

Btw, Barman, I don't understand how the two LAs can work against each other. Shouldn't they help each other by distributing the load among them?

The only way I can think of them working against each other, is if due to small inaccuracies in their manufacture they move at different speeds, and thus their movement is not properly synchronized. Right?

(btw, love your excavator :))

Anonymous said...

The H - frame/beam looks also to be a prototype, it's 7x11 instead of 5x11 ( the one we have now ).

Barman said...

@santi, thanks. This is the first version. I'm now at my third version and still not ready.

I can't explain why 1 LA works better than 2 LA's. I think it's the friction of the internal components. All LA's work at the same speed if they have the same gearing/drive.
That is the major error on the 8043. The 2 LA's are driven by the 20 single bevel gear with axle hole. These gears are put on the outside of the LA bracket (step 59 of the instructions, book 2, page 33). When the boom is raised in this highes position the LA's aren't of the same length. Then you put the 20 bevel gear with axle hole on one side (doesn't matter left or right) and that problem is gone.
It's a mistake a beginner will make, but I don't know way Anders and Ricco didn't see this.
Perhaps this error was made when the digitale model was made and in the instructions. That's probably why the testing of the model was great and when the set was released the problem started.

@Anonymous, you're right. That's cool. The yellow bucket is also interesting.

Like Tobbe Arnesson said, I like to see more of these interviews. Excellent work TBs :)


Wiseman_2 said...

This has been a great insightful interview, so thanks to all who made it possible.

Those prototype photos are really quite interesting, in this case we can see they obviously emphasized the gearbox to see if it could be switched.

Also, I am glad they used the bucket they did as the B-Model is great fun to play with and the bucket they used I don't really have a problem with.

@Anonymous: The H-Beam is the 7x11 one we have now, not a 5x11. It came out in 2009 when 8043 was in development.

TechnicBRICKs said...

Great that you enjoyed the images surprise, left to the last part! :)

It wouldn't be the same if they were included in the first parts, isn't it!?

Now let me try to comment your comments.


I don't think the 20 bevel gears positioning to be determinant into this problem. I remember to have seen this discussed at EB long ago, without a conclusion of "guilty".
Sure we have to be careful during the building process to avoid major misalignments among the LAs, and I still don't see this as an explanation to the problem, but the LAs internal friction and consequent erosion as shown here at TBs before. The new LAs seem to have improved these issues with their new internal design.

In fact I also believe the issue was somehow present in other models like the 8265 Front Loader.
The point is till when you consider it as an acceptable behavior or limitation, or when you admit/suspect there might be a real problem with your model. I remember that when I first played with the Excavator and made its review, I noticed the boom turned very slow too fast, but always thought the culprit were the 7,2V rechargeable batteries, consuming too fast because of the boom high load.
When you realize there is in fact a problem, suddenly it is everywhere, to different extents.
Only after a long play with the Excavator, you start to notice permanent damage in the LAs. First I was observing (probably wrong) some recovering every time I recharged the batteries. Some never noticed the problem and always accepted the boom should move that slow. The real problem is when it completely stops, because LAs are already in too bad shape...

Regarding your excavator and boom performance, the only difference I see is that your 1 LA setup pulls the boom while raising it, and those on the 8043, pushes the boom upwards.
Probably this explains it and makes all the difference in terms of LAs internal construction and friction. The LAs internal sleeve and screw are compressing/stressing at different points in both setups, and the internal profiles ma justify a difference in performance.
At least I remember to discuss also the different push/pull effects at another private dialog long ago.

Regarding the H-frame, indeed we see there a 7x11 version, while we got the 5x11 version released with 2H2009 sets.
By the time of these 8043 prototype images (2009), the 2H2009 sets should have beens almost ready if not totally ready.
So we may have here one new part and a few possibilities:
- one part prototype abandoned in between.
- one part still to be released with future.

The intriguing part is that it seems a well finished element, i.e. a real molded part and not any kind of 3D printed mock-up.
Thus I wonder that TLG produces a complete new mold to produce one part that was not already approved to be used in new models and to be produced. :/

The yellow bucket is also a nice nugget! Those kind of things that only the Designers have access for testing ideas and see how it fits, and which we probably will never get in our hands.
But specifically for the 8043, I still prefer they have used the black bucket. Maybe a yellow one would fit better at some other model!?

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