A better Surprise – 42057 MOC

A few weeks ago I was quite surprised by a random lucky find after having padded out an Amazon order without much further thought beforehand and ever since it has been on my mind to improve on some of the quirks the model also had. I dabbled around on and off on some evenings and tried many things until I arrived at something that satisfied me.

Note: I was oblivious to the limited capabilities of my old photo camera and for aesthetical reasons used a lot of elements in black, so things may be difficult to recognize. You should be able to determine the types of pins and axles used based on their colors and I’ve added call-outs for some critical elements to make things a bit easier, but if you have specific questions just fire away in the comments. I’m also considering building a model in LEGO Digital Designer and generate a building instruction, but this is still way off in the more distant future.

Objectives

First and foremost of course I wanted to get rid of the ugly motor and that shall be the primary focus of this article. Other things like replacing/ improving the rotor blades are left for a later date, as I haven’t yet really looked into alternatives, which presumably are going to be some sort of the City line stub-based helicopter rotor blades.

To make things not too complicated my goal was too retain as much of the original model as possible. This in particular meant to keep the overall proportions and appearance by re-using sub-assemblies that already exist. Thankfully, since the model out of the box is already designed to resemble a lightweight helicopter/ gyrocopter many sections are already constructed in a way to simply plug on to a central body like you would on the real thing.

E.g. for transportation purposes the aft tail would indeed be just a simple tube or scaffolding structure that can be transported side-by-side with the main fuselage in the same car trailer and then easily be bolted on at the airstrip’s preflight pad. Same for the main rotor or the various covers.

With that in mind I kept the overall logic of the groupings intact. You just have to be careful then to always move the entire group like for instance the seat assembly to retain functionality. On occasion it means however that you may have to move a few pins around or change their type so they plug into different holes and connectors.

Additionally I wanted to avoid the use of too many extra parts. I knew I would need some parts from my own inventory simply because they are not contained in the set and I also knew that I would need quite some pieces to create a custom engine rendition, but otherwise I tried to restrain myself and not go overboard. This is an affordable set, after all, an there seems no point in making it too difficult and too expensive for other people to customize it.

The clunky motor being the big stinker, it represented a few challenges to get rid of. Because it is used as a structural element, once it would be gone the model would lose a lot of its stability, so I had to come up with a way to compensate. On a similar note I also wanted to free the cockpit parts from their use as anchors for the elements that stabilize the main rotor’s bearing and shaft. This may seem unnecessary, but if I ever decided to customize the model ever further, it would facilitate things like replacing the panels

With all this it only seems natural that one would also want to improve other details also while at it. One simple thing is for instance adding all sorts of little lights to make things more lively and at least retain the illusion of the air vehicle complying with FAA regulations. 😉

Lego 42057 MOC, Overview

Basic Idea

To achieve what I wanted I knew I was going to need a lot more room or more specifically longer arms and more pin holes. Initially I thought it would be as simple as replacing the small L-shaped liftarm with the bigger version and then plug everything else onto it, so this acts as some kind of central girder/ bulkhead, but no such luck.

To even come close to that I first had to extend the length of the model while at the same time not actually making it longer. This contradictory requirement stems from the fact that in order to keep the functionality of the rotor gear you have to keep it as a compact unit, but at the same time sneak in those two or three extra pin holes. The bottom view illustrates this best.

Lego 42057 MOC, Bottom

The front beams are 11L instead of the kit’s 9L and likewise the original 5L side rocker bars made from two 0.5L thick elements have been superseded by a conventional 7L arm. To account for the increased length, the front wheel was moved one hole aft and the 7L liftarm equally has one more hole of overlap. The large L-shaped elements now fit in-between the rest without a gap. You just need a lot more pins and also move the connectors on the cockpit side panels.

Onto the top of the large L liftarms the smaller ones were attached horizontally and pointing forward, which would later serve to hold the gear shaft for the main rotor. With that in place, we can start thinking about the actual motor.

Motor Design

In the process of coming up with an alternate engine I must have tried  at least ten different designs. Ultimately I wanted this to be more representative of a small V-shaped four or six cylinder dual row engine as it very likely would be on a real aircraft of this kind – small, not too powerful, high rev engines that make a lot of noise, but run smoothly and reliably, avoiding vibrations and providing some safety margin in case of emergencies.

Unfortunately this turned out to be more complicated than I had anticipated. Since there are basically no wedge type/ angled lift arms that can be plugged together directly it all ends up being a mess. Any connector that you insert to produce a specifically add to the width, which has the potential of making things look way too bulky, even more so on a model that for a large part is only 5L wide or even narrower. Also the angled constructs lacked stability and it was difficult to add the axles for the transmission gear.

Lego 42057 MOC, Detail Aft

In the end I settled on something a lot simpler. I used an H shaped 5 x 3 liftarm (or “bone”, as I like to call them) as the base. At the bottom I added two pins with holes that would later act as the bearings for the big cog’s axle. On the sides I added two 5L liftarms onto which I built the “cylinders” using lots of grey bushings, axle pins, and 3L and 4L axles to fill in the open spaces. Two of the cylinder heads are again connectors with holes for the propeller axle. This is a straightforward construction that is robust and stable.

Lego 42057 MOC, Detail Engine, Top

The engine block then was fixated with a short T-type connector that is anchored between the two smaller L shapes on the main frame with a simple 3D axle. This has the advantage that as long as the bottom part is not locked down, you can swivel up the whole affair, which makes working on the lower parts easier. With this you also get an exchangeable modular platform onto which you can build other drive units like a small gas turbine or other engine variants. I fancied up mine by also adding exhaust pipes, which e.g. could be found in another small set like the speed racing boat (42045) and the red top light on a black pin, the latter of which plugs into the remaining free hole of the hinge mechanism.

Lego 42057 MOC, Detail Engine, Bottom

To properly work the bottom of the engine needs to be pinned down as well. I re-used the lower section of the original engine holder yellow axle, but modified things to make use of the now elsewhere redundant 0.5L thick liftarms. This made sure the delicate overall appearance was retained and provided just enough room to accommodate all those little axles and pins. So in essence the engine at the bottom is held up by a 3L pin going through one element affixed on the engine itself and the other two connectors on the frame clamping it in, as it were.

Lego 42057 MOC, Engine

Offsetting the connector for the aft beam by one unit also made for a more realistic look with the small propeller having a little more room. Sadly enough there’s no rivet-like pin with a flat or hemispheric stopper head, so I used the freed up ball-headed pins. This looks a bit odd, though. An alternative might be using stud adaptor pins and cover them with a red and green transparency, so this could double as board/ starboard formation lights.

Main Rotor

On the original model the main rotor is held by a somewhat awkward, yet at the same time almost ingenious construction that involves the two white sidewall panels. It plays on the tension of the two tubes used for the canopy frames and is built as a self-stabilizing block that really only works once you have flipped up the two connectors (page 46 of the building instructions). As I wrote in the first paragraph I wanted to come up with something simpler that would allow to remove the panels without affecting the rest, so I had to turn this on its head.

Lego 42057 MOC, Detail Left

Here’s where we revisit our two small L-shaped elements from earlier, as there’s still three empty holes to cover. In goes another connector, which is locked in place with a 3L axle in the front and a black axle pin in the rear. The protruding pin (and its matching counterpart ordinary black pin on the opposite side) then serve as a holder for two connectors in-between which a no. 2 axle-to-axle connector with pin hole is placed. Said pin hole is then occupied by yet another pin with hole and once you add the rotor axle into the mix – voilà, you get a pretty stable construct that holds the rotor firmly straight in place. Don’t worry! It sounds more complicated than it is and you’ll figure it out.

Lego 42057 MOC, Detail Engine

Details

After all the trouble all that is left is taking care of some details. I added yet more connectors to re-attach the small shields that cover the engine. Depending on what your preference in the matter is, you could leave them out or with a bit of creativity leave out the exhaust pipes and use just the shields.

Another considerable change/ improvement I made with the steering linkages for the rudder. Say what you will, not even the aft section running parallel to the beam looks just sloppy plus using the clunky 3L 40th anniversary white liftarm annoyed me. With the 4L lever type liftarm from the original motor holder no longer used anywhere, it came in handy here. The only caveat is that the direction is inverted and the freedom of movement is not as large, but I consider this a minor thing.

Due to using the longer liftarm on the base frame I also had a pin hole to spare to directly plug in the “stick”, allowing to omit the extra pins on the white panel. See the recurring theme here? with no obstructions in the way you can literally swap the panel for a different one in a minute and turn your little chopper into a police vehicle or fire surveillance plane using blue/ green or red panels, respectively.

Final Words

When building my models I do small changes all the time, but sitting down and making a dedicated effort to completely change someone else’s work is a whole different matter. It reveals that the logic applied to LEGO models is not necessarily in line with “how stuff works in the real world” and it also illustrates that different ways of thinking can result in completely different methods of approaching (engineering) problems in order to solve them. This isn’t always fun, but an interesting challenge no less.

With the engine part now being almost 100% foolproof I might indeed try and come up with some other methods of emulating drive units. There’s already ideas rummaging around in my head on how to do a jet turbine. Other things I’m contemplating is some work to build an elastic, damped and fully steerable undercarriage system and of course one could go crazy on detailing everything to your heart’s content. Even a bubble canopy now seems easy enough by just replacing the front section. and yes, that main rotor thing, too… 😉