Your vehicle MOC planning / building process

[Hrafn]

After seeing the comments here, I wondered what process others follow in building cars and other vehicles. My approach thus far has been:

1) determine what vehicle to model

2) figure out the scale

3) determine the wheels and tires used, to match the intended scale [this may actually come before 2) - in my current effort I picked the tires first, then determined the scale]

4) figure out roughly what features I want: suspension type (if any) per axle, which axles are driven, which ones are steered, whether there will be a gearbox, whether it will be motorized, etc.

5) build the axles

6) build a chassis and fit in the other features (gearbox, motors, etc.) desired

7) bodywork (not that I've gotten quite to this step yet...)

So far I've had to go back and revisit earlier steps a number of times - for example, I thought I was done with my axle designs but then found out that the motors I wanted to use were so strong they were tearing the rear axle assembly apart. Preliminary bodywork showed me that the shock towers were too high, so I had to redesign the front axle. And so on...

Is this similar to what you do? I was surprised to see Doc_Brown say he started with the bodywork (gorgeous though it is!) for his GTHO.

[piterx]

i usually look for wheels scale and axle scale, so very often it happens that i have to discard some cars i'd like to build because i can't keep the proportions right at the scale i want :P

then i build the front axle and all the rest following...

oh yeah i also discard some cars if panels can't provide a nice bodywork

[unimog123]

Ah yes, I hate it when there are no panels in the shape you need.

I usually start with what I want to model, then if I have the appropriate motors, colors, parts, and so on, I also make sure the tires look similar to the real vehicle in shape and size. Then I usually start with the easiest axle (usually rear axle) and continue up the chassis and construct the front axle last, although for more complex models this process might not work because the front axle has to fit a certain way instead of the chassis fitting the front axle, if you get what I mean . Finally I work on the bodywork, which is almost always the hardest for me.

[piterx]

the new wheels are PERFECT for my next moc :P

size, shape and proportions...everything's just perfect lol

i can just say it will be a rally car

how do you build the front axle later? o.o

[Meatman]

Here is a nice article that one of our own here wrote about building cars. Most of this would probably apply to just about any vehicle though as it is pretty general.

[Anio]

a) Find the key features of the model you want to do, both regarding the look and the functions

d) Make logical choices to get consistent specifications

c) Focus on part that can be considered as critical regarding the building process

d) Keep it simple and optimised.

[unimog123]

the new wheels are PERFECT for my next moc :P

size, shape and proportions...everything's just perfect lol

i can just say it will be a rally car

how do you build the front axle later? o.o

I can not wait for this rally car, I might actually start my rally car project soon. :excited:

Yeah, I know it's kind of weird, but somehow I figure out how to make the front axle last. Nonetheless though, it does not always come out the best. This actually happened in both my Trophy Truck and Roadster.

[JM1971]

the new wheels are PERFECT for my next moc :P

size, shape and proportions...everything's just perfect lol

i can just say it will be a rally car

how do you build the front axle later? o.o

Also looking forward to that rally car very much

As for building, I usually place the wheels first and hope everything fits, lolz.

Edited March 17, 2014 by JM1971

[Hrafn]

the new wheels are PERFECT for my next moc :P

size, shape and proportions...everything's just perfect lol

i can just say it will be a rally car

how do you build the front axle later? o.o

Woo! Your Fulvia is what inspired me to work on a rally car, though since it's my first Technic MOC it's going veeerrry slowly. I'm looking forward to seeing your new one!

[Lipko]

It depends on the project: if it's modeled of a real car, then I make the body first with a temporary chassis. I did that with the Hammer project, it failed for other reasons.

Obviously the scale is the first to decide, based on the wheels and other factors, like fake engine size, whether the front axle is driven or not, etc. I usually start this process in LDD and try to find the best wheels.

I usually make a prototype model first to see if the model looks as good as I imagined. It usually looks good, so usually my design process ends here...

[Cumulonimbus]

I design my MOD's and MOC's in a slightly different way. As an Industrial Designer I have been taught to divide a design problem into sub-problems. In Lego I apply this technique as well: after choosing the machine and the scale, I divide the model into functional units or sub-problems. I solve the challenges for each unit before building them into a single model. Often, I make a mock-up of the body so I can fit all the modules in it, while not have to worry about the inadvertently changing the proportions.

The advantage is that in the first stages, I’m independent of the available colors and I can try different versions or solutions and interchange them in the model. It also allows me to make quick iterations until I find an optimal solution. Eventually, I have a model which is a collection of solutions for each sub-problem in a mock-up body. This should look and work like the final thing, but it can be over engineered and is a collection of available colors.

Once I have a completed model, my last step is to use this model as an example to completely rebuild it. In this step, I choose a color scheme, integrate functions, simplify the construction and add rigidity if needed.

The drawback is that you need a lot of parts, as at any given moment you need about twice the amount of parts of the final model. Especially with rare parts, this can be an issue.

[Lipko]

And how do you deal with the "interfaces" between the modules?

I'm a machine constructor too but I find it hard to use those design methods with Lego, because the available parts and the weakness of the material is so constraining. In real life I can solve problems easily with custom parts (maybe it won't be optimal, but gets the job done) but with Lego, it's hard for me to come up with any solutions at all given the constrains. Even if I solve something, it will interfere with something else.

And if I solve everything, and everything works okay, I still have an ugly messy build, not something I'd call art.

In machine design, you usually come up with many solution sketch variations for a problem, but with Lego I find it extremely time consuming, because you can't just "sketch". You have to build variations which costs a lot of time and pieces.

And no matter how I try to make plans, I always end up just hacking something. There's maybe a mental barrier or something. I'm thinking backwards. If I find a piece, I'm looking what to solve with it, not the other way around.

The one thing does make building easier for me is to build in modules. It is much easier than I first thought, and it lets you to optimize modules without the need of disassembling the whole model.

In fact, Lego design is so frustratingly hard for me that I'm really considering giving it up after my last model, which I'm building for a half year now.

Rant over.

Edited March 18, 2014 by Lipko

[Cumulonimbus]

You are right, the interface between the modules and functions is the tricky part of this method. I simplified the explanation a bit when I explained it, in reality, many iterations are needed. Often I start with the most challenging module and once solved continue further with this module in mind.

It’s hard to explain, but I see designing a Lego set like a mathematical problem. You have a number of variables (model functions, orientation of parts, …) and a number of givens (available parts, scale, stud thickness, ...). With the huge amount of variations, I assume that there is always a solution possible. The fascinating thing is that this is not an unique solution, hence the many variation of MOC’s and MOD’s people can make.

In other words: during building I seem to have a collection of boundary conditions in my head while searching for a particular solution. For example: “I need to guide the forces from the rear wheels through this module, while keeping the frame max 5L wide”. I go back and forth while building until I get a eureka moment where the thing I built complies to all requirements.

Now and then I get stuck as there doesn’t seem to be a solution fitting all the requirements. Then I either set the building to one side to let it rest (inspiration comes at the most strange times and locations) or reduce the complexity by eliminating a function for example.

I must confess, the learning curve of building studless after my dark ages was quite challenging, but learning how Lego does it was a great way to start. The 8258 set was a real eye-opener for me in this respect: The chassis consists of similar modules, for example the part where the crane sits on.

[Jeroen Ottens]

I use a similar approach as Cumulonimbus, however I have started to use LDD heavily for the module part. It has the advantage that you have an unlimited amount of parts available and it is very easy to swap one part that is right inside your structure. The disadvantage is that you have to have a good feeling for the rigidity of the structure. You sort of have to make a mental map of the structural components of the build otherwise it will fall apart when building it. Or you find that you have created an impossible construction.

One thing that I find is virtually impossible to do in LDD is the bodywork. You just can't see the flow and lines of your design. But once the inside of the car is finished, the outside is much easier to make using real lego.

[Lakop]

I've been using LDD recently for chassis building. I'm still finding my way around it but so far so good. I only use the parts I know I have, that way I know I can build it for real. Hopefully I will produce a model from it soon.

H

[Alasdair Ryan]

I have a new approach due to lack of time...think of something then pay Zblj to build it.

[gregorijs3kivi]

Build the chassis

Drive it

Break it

Fix it

Improve it

Drive it

Build the body

Drive it

Go sleep

[mahjqa]

The process is remarkably similar to this: threepanelsoul link

Identify the hardest part. Start with that.

[dhc6twinotter]

1) Find something I want to build

2) Write down the functions and what kind of motor should power it

3) If more than 8 functions, I group the functions into the most logical pairs to operate through a gearbox

4) Make a rough sketch of gearing and functions layout

5) Scale to tires

6) Build the insides first, starting with the hardest part(s)

7) Build body

8) Test and probably rebuild (I often rebuild most parts of a moc at least once, sometimes many more times)

Edited March 19, 2014 by dhc6twinotter

[rm8]

Since i dont have free time now (2 job simultaneously), I build lego in my head during days. Some ideas in my head are very old, but still not realized in bricks.

If I want to make a copy (all my plans are copys now), I have to be sure that I can make some body elements with existing lego pieces. Sometimes I calculate the scale using not wheels (as many do) as starting point, but technc panels (for example panels for bonnet). Since I like to build offroaders, wheel size is not a problem when I calculate scale: you can always use a liitle bit larger wheel and lifted suspension, just be sure that final result is not a Monster Truck:)

When I want to replicate some key and well-known details of real model (usually it is a front lights with grille, and some unique body shapes) - I can start from building this parts first, using Lego system parts also. Often, you can make good body, but if front lights with grille are copied bad - final result is also bad.

1 month ago I installed LDD to my netbook (working slow, but better than in my head:)). I learned it fast, and now I have very good modelled body of my future project. I spent a little time, comparing with real bricks building. Now I can start with bricks, using LDD model and I am sure that final result will be awesome.

Reccomend try LDD to everybody!, who did not discovered it yet;)

Edited March 19, 2014 by rm8

[Cumulonimbus]

On a related note: what do we know about the developing process of Lego itself? Based on stuff I saw and read in the last years, the following list is what I can reconstruct:

1. What to build. Nobody exactly knows how a machine is chosen by TLG, but there are some indications:
   

A. Popular machines get repeated every few years. For example: about every 3 years a Technic bike is developed, in the last decade street bikes and dirt bikes are alternated, so about 5 years a new generation is designed. So I predict a new street bike in 2015.

B. Additionally, it is apparent that some machines such as cranes, shovels, fork lifts and trucks are very popular with the target customers (aka kids).

1. Scale. TLG must design sets for each price bracket each half year and the target price will determine the scale (mainly determined by number of parts).
   
2. Mock-ups. In complex cases, a proof of principle is made. For example the RC system of the 8043 Excavator was demonstrated with a crude mock-up.
   
3. Prototypes. Several prototypes are made to be able to decide on crucial aspects such as pneumatic vs LA’s, tire choice, color scheme, etc. Most famous example is the 8110 Unimog where different prototypes were displayed after the final model was launched. I have also seen images of the 8291Dirtbike with different color schemes for the body panels and rims.
   
4. Rebuild. I read somewhere on the Technic site that the designers rebuild new models up to seven (I think) times, until they are fully satisfied with the functions, structure, amount of parts, etc
   
5. Launch. As TLG is a commercial company they must also develop the rest of the processes (manuals, box art, packaging, marketing, distribution, etc)