42093 Model C – Sand Buggy
An alternate model of the 42093 – Corvette ZR1 as a sand buggy, features steering, fake L3 engine and suspensions, with building instructions.
Few months ago, I have reviewed the #42093 Corvette ZR1 set, and I though it was a very great set, for display, for beginner or for the parts. Then I wanted to created an alternate model to try to re-use the inventory to create something different with the difficulty and compromise inherent to this process. Here is the result.
The 42093 set is now a pretty old set, which means that there are many of alternate builds available on Rebrickable. That is why I wanted to create something different in functions, to not only create a steering / fake engine vehicle, but add a nice function which would not have been done before. This function is the suspensions.
The rear suspension is an oscillating rear axle made with the unique soft-axle in the set. The front suspensions are double wishbones suspensions, with torsion bars. You can see these torsion bars underneath the chassis with perpendicular orange connector and 1/2 pin which create the end stop and the correct angle of rest position. The length of the torsion bar is 11L which ensures a good travel and soft suspension but hard enough to not damage the axle in rest position (the weight is not enough to twist the torsion bar which is an important feature for a playset).
The other functions are quite classic. The hand of god on the roof operates the steering with a 12t/12t bevel gearing, which operates a fork-lever system connected to the front axle steering. The design key here is that the linkage between the two wheels is an articulated linkage which floats on the fork-lever system. It enables to operate the steering with the suspensions without the need to have ball joints (which are not present in the set). But of course this solution is not suitable for big vehicle because of the play in the mechanism.
The last functions is the fake L3 engine, which is pretty small comparing to the original V8 of the Corvette ! It uses the same principle but use 1/2 pin instead of 3L axle which gives a smaller construction. The key features is that this engine is mounted on the oscillating axle due to the available room in the creation, but is driven by spur gear on the differential with a 20t gear. This is a pretty unusual solution, not use by Lego, because it needs some play to work (that is why there no bush between the 20t gear and the 2L beam). It allows to have a very compact solution to mount of the axle comparing to a classic bevel construction.
Functions are important for a playset, but design too ! It has to catch the eyes by the shape, the colour, the details, but also have a smooth / homogeneous design, and at this scale the design is part of the chassis and functions. Ok, that’s a lot for a 453-parts small set. Therefore, the approach have been to create the chassis and the functions to validate the raw dimensions regarding the size of the wheel and the available space, and then started the design process.
I have been inspired by SVV vehicle from Segway or other buggy because of the leaning design of the front part, with lifted rear which enables to have a great and recognizable look despite the size of the creation (It would have been difficult for instance to reproduce a other licensed car like a Ferrari). I have tried many variations for the design with frame-looking or more paneled one. But as usual with small creations, this is the parts which mostly guide the design . That is why I use the available mudguards and panels for the bodywork but with some angled builds, like the front shape and the side. Then I have added some details to “polish” the creation, with seats, dashboard, light, exhaust, radiator but also fill some empty space. The only improving point for me is that I would have preferred to have more ‘all terrain tires’ to enhance the look of the creations.
Photos and Video
As for my previous alternate model, I have created the building instructions. This is a pro-looking 3D-rendering building instructions with step by step partlist, in a same way as the Lego do. You only required the parts of the original #42093 set to build this alternate model.
But if you want to build it with your own collection, you can checked the bill of material on Rebrickable and export in whatever format you want :
After your payment, you will be redirected to a page for downloading your instructions, and will receive also the link to download by email. Please check the spam box and be patient to receive it. If you have trouble to download your copy of the PDF after payment or open the document, do not make a paypal dispute, please contact me using the contact form. The link to download the instructions expires within 24h. Contact me if you have lost your instructions. Note that you can print it, but not copy or distribute. Thank you for supporting my work 🙂
Here is some preview of the building instructions :