[MOC] Mini 42052 - Heavy Lift Helicopter

[Ngoc Nguyen]

How small can a mini replica go? What is the ultimate limit of a mini replica? Those are very profound questions that I certainly... did NOT set out to answer  You got that right, I wasn't trying to do so at all, and this mini replica was totally not in my plan. So how did it come to life? Let's find out.

 

DEVELOPMENT

I have actually wanted to do a mini 42052 for a while, and I did do some sketches, but there were a few problems. The first one is the scale. The original 42052 has an awkward width and height of 13 studs, while the length is around 43 studs. Those are hard numbers to work with, and I couldnt settle on the scaling down ratio. Originally I intended to use the Osprey blade, which has a length of 19. Since the original 42052's blade has a length of 31, the calculation of 19/31*13 gives 7.96, so the corresponding width should be 7 studs. But at that scale, I ran into a second problem.

I couldnt decide whether the mini replica should be motorized or not. Those who follow me will know that I already did another mini helicopter before, the mini 42145. Because its functions are simple, it is feasible to scale it down while still keep it motorized. Hence its width was chosen to be 9 studs, so that a simple hub can be accommodated into the build.

It is not really fitting for 42052 to follow the same path. The original 42052 has an openable belly, so if it's to be motorized, the battery box will block not just the belly but also the winch going through it. I want to replicate all the functions, so that direction is a no-go. But if it's not motorized, then all functions would be manual, but then the scale of 9 stud width will be an overkill because there's nothing to fill the inside. The model will be just a boring hollow box with direct drive functions.

I wasn't able to find a definitive solution, so the idea just stayed at the back of my mind for a while. Then one afternoon in March I was fiddling around to do an alternate model, which shall not be revealed just yet,  and I tried attaching a 3 blade submodel using the smallest blade (99012) on a 28z turntable. That was when I realized, what if I scaled down the 42052 by the factor of 1/3?! It would be compact enough to make an interesting build, and it works with the original dimensions of 42052 too! 1/3 * 13 is 4.33, which means I can do a model with a height and a width of 5 studs. The length can be 14 studs, and so I started working on it!

The build is relatively straightforward. The counterrotation can be achieved with a 28z turntable on top and a 28z gear in the bottom. The 28z gear has a diameter of 4 studs, but luckily enough there are engine cowls on both sids, so I used them to hide the 28z gears.

 

Surprisingly, the function that gave me quite a bit of challenge turned out to be a winch. In such a small area, I had to put a string drum somewhere, and it needs to be held with friction. Since the model is covered on all sides, using a ratchet is not possible. At the same time there must be reinforcing liftarms to keep the build structurally sound. The solution was, as it turned out, counterintuitively, to use the big drum with a friction axle pin on one side and a knob on the other. Since there's also no space for a proper hook, I used the pneumatic T-piece attached to a 1/2 friction pin instead.

 

And you can also see that there's a space of 1 stud in the rear, above the wheel. I intentionally cleared that space so that the green liftarm can be stored in the back, just like in the official 42052.

See how it all works here.

 

And that leads to the most compact mini replica ever in my collection, only 271 pieces! Im very happy with how this turns out, especially when it started from just some random trials. There's a certain charm in small things. Look how cute it is!

 

Function sheets:

 

 

Instruction: https://reb.li/m/223646

[JoKo]

So cute! 

[Ngoc Nguyen]

2 minutes ago, JoKo said:

So cute! 

I know right!!

[Paul B Technic]

Amazing work.

[Ngoc Nguyen]

2 hours ago, Paul B Technic said:

Amazing work.

Thank you Paul as always.

[Bartybum]

Hehehe this is awesome, very cute build

[Ngoc Nguyen]

12 minutes ago, Bartybum said:

Hehehe this is awesome, very cute build

Thanks! Such cuteness is irresistable!

[Thirdwigg]

This is so fun. Great solutions too!

[Ngoc Nguyen]

23 minutes ago, Thirdwigg said:

This is so fun. Great solutions too!

It was indeed very fun to work on this model, especially when it was started purely on a whim!