After too long, I can finally spend some time on my favorite hobby again. I want to make an alt build for the VTOL Heavy cargo spaceship LT81. Just like with the Gi-ant, I intend to write some posts about how I go about doing this because it may help answer many aspiring MOC builders who are getting stuck at the start or later on. Another reason for writing these posts is that they help me reflect on my own ways of working, and hopefully improve them. If you have any comments or questions, please do enter them below.

The post is clearly split up in different sections. Some are about my thoughts about a ‘method’ for designing any alternative build. Other sections are about applying them to an alternate build of the VTOL cargo ship. So, you can easily skip either of the two if you feel like that. While I am writing this post, I have not yet made that MOC, so for me it is exciting to see what will come out and if I can get somewhere following my own ‘method’.

Actually, ‘method’ is too big a word. Basically there are two starting points: 1) the limited supply of bricks of an existing set, 2) your ideas. Then the third point is to bring them together to see if they match, that is to see if you can likely build your idea with the limited supply of bricks. These are the topics of the chapters 1 to 3. Chapter 2 has a section that summarizes my idea for an alternative VTOL cargo space ship. Lastly, chapter 4 is an example of doing the matching between my idea and the existing set.

 

1 Limited versus unlimited supply of bricks

For designing a MOC, a very important starting condition is whether you work with a limited supply of bricks or an unlimited one. Nobody has an unlimited supply of bricks, obviously. Not even TLG. However, if you have the means you can buy any of the bricks in existence through Lego’s pick-a-brick and websites like BrickLink. That is what I would call an unlimited supply.

Most people work with a limited supply of bricks, either because they do not have the means to buy additional bricks, or because they choose not to. I occasionally have bought additional bricks for my designs, but in this case, I choose to make an alternative build ( or ‘alt build’ ) of an existing set. One reason is that it helps making the design findable in Rebrickable for those that have the same set. Another is that at least those who already own the set have a limited supply of bricks that is guaranteed to be sufficiently big.

If it later turns out that I am unable to design exactly what I had in mind with the bricks of the set, I can always change towards the unlimited supply way of working by adding bricks from my collection of bricks. Or, I could make two versions: an alt build which I find sub-optimal, and an improved version for those who have the bricks. I did this with the Dragonfly ( an alt build of the Motorcycle, 42132 ) and the Dragonfly mk II. In fact, I do not own the bricks of the second version of the Dragonfly myself. Also, even though the second version is better, the first one is viewed three times more often, which I think is caused by the fact that it is less easy to find than the alt build version.

In this case, I choose the VTOL Heavy cargo spaceship LT81 to make an alt build. The main reason for it is that it is my newest relatively big set, and I have not made an alt build out of this one. Also, while building it and having it on display in my cave / room for a while, I got an idea. How to get ideas is the topic of the next chapter.

 

2 Getting ideas

The second basic starting point is that you need to get or have ideas for a MOC. There are no fail safe methods for this. Others have written about it already, so I will just sum up some that I read about and that I invented : 1) start building something, anything, and at some point an idea will present itself. 2) play with the bricks in your hands. 3) make modifications of the existing model. 4) draw a blob on paper and try to fill it in. 5) wait for an idea. 6) ask someone else for suggestions.

What they all seem to boil down to, is that you just have to start with something. Anything will do. It does not have to be the final idea for the particular MOC that you will design. Just consider it as ‘merely’ the first, not the last and not the best. Therefore, do not spend too much time on an idea. Maybe you should force yourself to come up with at least, say, three ideas before you pick one to continue with. I talk this talk, but I don’t walk it myself, at least not in this post. As you will see, I have just one idea. However, I am sure that I will have to design different versions.

Do not get attached to your idea any time soon, because you may not be able to finish it. I have spent weeks tinkering on a fairly big design of a technic caterpillar bug before I realized I was on completely on the wrong track. I ditched it and went on with something completely different. I still want to make a caterpillar, but I am waiting for inspiration and energy to give it another attempt.

When you have made a MOC, you may be disappointed that it got nowhere close to your original idea, and keep berating yourself for it, or excusing yourself for it towards others. That is a waste of your energy. The people who see your MOC will … well … see your MOC. Not your original idea. So you can stop pestering yourself about it not being the original idea.

Some authors claim that getting ideas ( for a book, painting, sculpture, film, anything creative ) is nothing special really, and something you learn by doing. Maybe so. I haven’t gotten enough experience to say anything about it.

And sometimes, all the above goes out the door, and there is another method of getting an idea, and it is immediately the best. In the end, it is about creativity. Nobody has cracked it. That is, nobody has the manual for it. Don’t worry, just get going and keep at it!

 

2A Another VTOL cargo ship

My idea for an alt built came from some thinking about pro’s and cons of the design of the existing set.

Starting with the cons, the VTOL Heavy cargo spaceship LT81 looks good, but when you think about it, it won’t work in real life: the engines are wrongly placed. I think it will tend to topple over backwards when it tries to lift off with the front engines turned downwards. Especially if it is holding cargo because the cargo is being held behind those engines instead of in between them. Or, if it does not topple over, the back end will drag over the floor.

My second beef is that it has a hollow space inside, in which the cargo could go. But it does not. The cargo hangs underneath the ship and the hollow space is used for the hand that holds the ship when in flight. In itself the carrying handle is a neat. It allows one to hold the ship with and then use the thumb to handle the controls. Unfortunately, the ship is too heavy to hold and swoosh around for some time, and actually moving the controls is not very easy.

What I do like about the ship is the sleek shape, thanks to the extensive use of panels. For me, this is a relatively new way of shaping a Technic model, so I am looking forward to using them.

What I adore about the model, are the folding mechanisms for the landing skis and the cargo ‘crane’. They not only fold, but they also have a ‘dead point’ ( for my lack of a better word ) and stay in place once they pass that point. Once the landing skis are retracted, they stay in place.

Putting these points together, I want to make a VTOL cargo spaceship which has engines placed such that it seems more likely to work in real life, and which has some folding mechanism to hold the cargo inside the ship instead of under the ship. These, I would call the essential features of my idea. I deliberately keep the idea simple, that is, with a small amount of essential features. The more such features I define, the harder it will be to arrive at a MOC. This has to do with what comes next.

 

2B What next?

Getting the ideas is one thing, but remember, this post is about working with the limited supply of bricks provided by an existing set. So there is a third point of bringing your idea(s) together with the limited supply.

 

3 Your limited supply versus your ideas

So, you have one or more ideas and your limited supply of bricks. Now comes the third starting point, which is the confrontation between the two. For each idea, you will need to consider at least the size of the limited supply, the essential features of the model, and its scale.

 

3A The size of the limited supply

The ideas that you generate do have to roughly fit the limited supply of bricks that you have. This is easily said, and, to a point, also easily done. To get an idea easily implemented with a limited supply, you can adjust the scale. I.e. make the model smaller. The second easy way out is to implement the idea with fewer details. The two can easily go hand in hand, because if the model is smaller it has less space for detail. Put simpler, you can make a church with 3 bricks, 30 bricks, 300 bricks, 3000 bricks or even more.

The difficult way out is to maximize the amount of bricks that you use within the limited supply that you have. If you have 300 bricks, you can easily make a church of 3 or 30 bricks. But can you make a church that uses exactly 300 bricks, or maybe a little less. I am no perfectionist in this respect. If I can make a great church or even a decent church out of half that amount of bricks, I would be very happy.

 

3B Essential features

However, it is not only a matter of brick counts, but also of which bricks you have: which shapes, sizes and colors? Here, all depends on what you, or your average audience, would consider a recognizable implementation of your idea. Since you are stuck with the limited supply, the sky is not the limit. I tend to think, what are absolutely essential characteristics of my idea? Do I have the bricks needed for those, and enough of other bricks for the rest?

Let’s start with the first: do I have the bricks needed for the essential details? Let’s keep it simple and assume I want to make a car. Well, in my mind, an essential feature of a car is that it has four wheels. It could be 6 or 8, perhaps even 3, but not one or 2. So, my limited supply of bricks needs to contain four wheels.

It could be that essential details can be made with one type of brick, like the wheels in the example, but it could be that you need more bricks to build such a feature. Moreover, the feature may be so complex that you have to build it to find out if you have the necessary bricks.

 

3C Scale and the total size of the model

The answer to the next question will depend on the size of the essential features. Do you have enough bricks and of more or less the right kind and color to build the rest? The important thing here is that the features are assembled together in an overall model of the same scale.

If the wheels that you have are say, 5 studs in diameter, your car may be about 33 studs long. Do you have enough other bricks to build a 33 stud long car? If not then again, you need to adjust your idea, which is more than fine, or abandon your idea, which is also fine. For the 33 studs, I have a Toyota Prius in mind. Your car may be different, but with four wheels with a 5 stud diameter, that car is not likely as small as 15 suds or as big as 80 studs. It might be, but maybe people don’t recognize it as a car anymore. If that is the car that you want anyways, then that is fine with me. In fact, I would encourage you to make it. There are plenty of boring MOC car designs out there.

The issue of scale not only applies to ‘the rest’ of your idea, but also to the essential features if your idea has multiple such features. Those features need to fit with each other in terms of their relative sizes. Let’s say that you not only want the car to have four wheels but also a wind shield, then they need to fit together in size according to your idea. If they do not fit, then you are of course free to change your idea. If you can not bend your mind that way, then you can discard your idea and go to the next.

3D Concluding remarks

The previous sections perhaps suggest that testing your idea against your limited supply of bricks is a lot of work. It may be but it does not have to be. It can be so trivial that you do not notice that you are doing it. It also can indeed be a lot of work. The important thing is to realize that it will happen, whether you do it deliberately or not. If you just start building, do not let me stop you. You may have a great time. It is just that you may get stuck simply because of the mismatch between your idea and the limited set of brick that you have. In short, your idea may too big or too complex and you just can not get it done with what you have.

Perhaps this is a no-brainer, but the more similar your idea is to the existing model, the more likely it is that you can make it. Making another car out of an existing car set should be better doable than making a church, airplane or fish out of the same set. If you want to come up with a remarkable alt build, the trick is to see if or how you could make a fish out of a car. Taking the existing set apart and then looking at the pieces instead of the whole may help you do so.

I want to make a different VTOL cargo spaceship out of an existing model of one, so it should be relatively easy to see if that may be possible. Still, I am going to check this in the next chapter.

 

4 Would another VTOL cargo spaceship be possible?

After all the experience-based theory, this section brings it into practice. I will consider if my idea matches with the limited supply of the original set. Is it likely that I can make my idea with the bricks of the VTOL Heavy cargo spaceship LT81?

First, let me have a look at what I have. I took apart my VTOL cargo ship and sorted it in boxes, like this.

 

You may have a different sorting style and system. No matter which one you use, the important thing here is that doing the sorting gives a great sense of which bricks you have. Next step, I am going to check them against the essential features of my idea.

 

4A Essential feature : Three or four engines

I need three or four engines or engine pods. The original set ( of the VTOL Heavy cargo spaceship LT81 ) has four, but they are not exactly the same when it comes to the panels they have on the outside. But there are 16 long ( 11 studs ) corner panels, 8 in orange, 4 in black and 4 in white. The white ones, or at least four will be needed to make the container that the ship needs to lift. Apparently that is an essential feature that I overlooked. Or I can decide not to make the container. Nah … I need the container. Each engine pod needs four corner panels, which means that I can only make 3 engine pods. Unless I use the four 7 stud corner panels plus something additional.

 

There are four sets of parts for the engines cones, which I could use, and 6 trans clear light blue connector bricks which seem great. I am not sure if I will need them all, but I can make at least 4 engines. There are six blue connector bricks, so if I make only 3 engines, I could use 2 for each engine.

 

So, when it comes down to engine count, I can make a three or four engine version of my ship. I guess that four gives a more recognizable spaceship because it will roughly look like a drone. If I use three engines, then the ship will become triangular, which may be less recognizable, but I really like non-rectangular building with Technic, so I may end up doing that anyway. On to the next essential feature.

 

4B Essential feature : Folding mechanism

What I would love to make, is a mechanism that makes the entire ship drop, sink or squat over the container, grab it and stands up again, or flies away. A bit like how a sea star just drops over its prey ( now that would be really something to build in Technic, but that’s for another day ). First I thought of the engines spreading outward, but that makes no sense because then the ship would not be able to lift off. So, maybe, they should move up and down along the vertical axis of the ship.

Well, whatever it is going to be, I will start with copying and then adapting the folding mechanisms that the original set has, which means. For this, I need a lot of bars. Fortunately, and not coincidentally, the model has a lot of bars

 

• 11 studs : 13 in orange, 11 in black, and 3 in white
   
• 9 studs : 11 in black and 8 in white
   
• 7 studs : 4 in black, 3 in white and 6 in light bluish grey
   
• 5 studs : 2 in orange, 7 in black and 2 in white
   

The model also has some angled bars in sets of two and four, as you can see in this picture

 

Since I will need three or four copies of the folding mechanism, I will need multiples of three or four of these bars. As you have noticed, there are some hits and misses, so I may be forced to make three, and/or I may have to compromise on the color scheme to make four copies. At this point, I do not have the brains to know for sure, until I start building. Whereas with the engines, I am confident that I can make up to four engines and engine pods, with the folding mechanisms, I am not. This then is one of the first things to attempt to make, so that I know early on whether I have a good chance to finish this project or not.

 

4C Scale and size

As I mentioned, I should also check if it is likely that I can design the overall spaceship with the parts that I have. In this case, I need a frame to put everything together. The original set does not offer a lot of long bars ( only 6 bars of 15 studs, 2 white and 4 black ), but it does have a nice set of frames. One of 11 x 15 studs, one of 3 x 19 studs and four A shaped frames.

 

The rectangular frames suggest a four-engine ship, but I could still be tempted to try three. How a three-engine version would fit around a rectangular container might be a puzzle that cannot be solved within the limited supply of bricks of the original set.

The original set does have a big supply of these 2 x 3 x 5 … uh … ‘panels’. They feel like curved solid bricks, and have a lot of pin holes, so they could be used very well as connector blocks. The original set also has some of these relatively new bars and hooks with pin holes in two directions. Those will have the future of Technic if you ask me, and I can hardly wait to make some more geometrical MOCs with them. ( again another project ). Until then, I do hope to put them to good use in my VTOL cargo spaceship.

 

In terms of decorative panels, there is plenty, and it has a probably sufficient amount of connectors, pins and axles, so I am not worried about those. But I do worry about the amount of gears. I can only hope that if the original set does not need that many, I may not either because my MOC will be similar to it, or at least not that dissimilar.

 

4D Conclusion

In short, except for the folding mechanisms, I think it should be possible to realize my idea for an alternative VTOL cargo spaceship. So, those folding mechanisms will be the next thing to work on. With a bit of luck, I may be able to post about them.

 

Frank van der Most, 16 May 2026