42127 Model B – Bucket Hot Rod

An alternate model of the 42127 – Batmobile , as a Bucket Hot Rod. Features, steering connected to the steering wheel, RWD with fake V8 engine, opening doors, removable hard top, and light bricks in the engine and on the rear light, with building instructions.


See it on the shop

An alternate model of the LEGO Technic Set 42127 – Batmobile, as a Bucket Hot Rod. Features, steering connected to the steering wheel, rear wheel drive with fake V8 engine, opening doors, removable hard top, light bricks in the engine and on the rear light.

Rebrickable partlist (842 parts). Preview of the instructions at the end of the article. Presentation Video (YouTube).


When the 42127 – Batmobile, was announced, it was a “meh” for me. Nice looking (especially the front) but a lack of functions for 1359 parts set : no suspensions, no working steering wheel, and of course no B model. The light bricks are cool features in Technic but the rear one is failed for me, as it is too far from the engine to illuminate correctly. That is why I wanted to make an alternate model of this set. There were not many options because of the different sizes between the front and rear wheels, so I chose to make a Bucket Hot Rod, in order to have a removable roof, for a better accessibility to the steering (and nice look too).



The steering is made using a classic rack and pinion solution, but I have put the pinion underneath the rack to have the steering axle as low as possible in the chassis to keep a low profile for a better looking. Then the steering axle goes to double bevel gearing to put the axle horizontally on the left. Then a U-join is used to connected it to the steering wheel. I had not enough place or clutch gearing to add a HOG so I decided to keep only the connection to the steering wheel in order to have a correct construction.


The drivetrain is rather simple. The rear differential is connected to the engine with a straight axle which crosses the entire chassis and interior. Due to the difference of size of the tires, I have put the rear axle higher to keep good proportion regarding ground clearance which made it visible in the passengers area. That is why I have hidden it under a central console which also acts as the reinforcement of the structure.


The lighting functions are interesting. I wanted to have a better illumination of the engine than the original model, that is why I have chosen to use the yellow light bricks on the engine which is stronger, and keep the red one for the rear lights. I have used this part on a side of the engine, where the light is, because it has a massive central hole which enables to illuminate the engine easily though the transparent material of the cylinders. Then, I have placed the light bricks on the correct height and as close as possible to have the best illumination possible. A lever placed on the center of dashboard is used to push the button on the light brick. The construction is made in a way that this lever is locked against the light bricks button when it is on, to ensure a constant functioning without having to operate continuously the lever (and a very satisfying clicking sound).


The rear lights are not properly multiple lights on each side, but more a central lights composed of the red transparent lightsaber, where the differential can be seen. The red light brick is located behind the seats, on the left of the differential, which results in a complex building with plates to have the correct height without touching the differential. The light power is lower as it is placed further, but as the lightsabers are transparent red, it is enough to illuminate them. The button of the light brick is operated with a small lever located between the seat with a friction pin to ensure a constant functioning.


To finish with more design functions, the doors can be open, revealed a detailed interior with dashboard (with use of the original stickers), seats and central console. The hard top can be removed to have a better accessibility to the steering wheel. I wanted at first to make a convertible roof, but I did not succeed with the parts, and in keeping the profile as low as possible. There were simply not enough room to store the convertible roof on the rear axle without damaging the look, that is why I have created a hard top instead.


Design Process

The design process is not very interesting regarding how I planed the model, but it is interesting in some building techniques. First I have started working on the front axle and a basic chassis, to have the lower profile as possible and scale the creation. Then I created the front grill which is an important and distinctive element. Then I created the engine with the light brick and its detail such as the intakes and exhausts because it has to look powerful. After that I reworked the chassis and created the rear axle and then connected the whole together. At this point, I have a pretty good idea what the model would look. I worked next on the steering wheel gearing and the interior, and to finish the rear details and light bricks. After some day, watching the creation and playing with, I have made some improvements, and it was done.

The first building technique is how I create the steering column. It has to handle the gearing and the correct angle of the steering wheel, despite the lack of any fixed connector. I have used this part on one side, and two of this part on the other side which was not easy to implemented on the whole assembly with the U-join and connection with the bodywork and the chassis. It results in a very dense and complex structure which I am proud of.


The second building technique is how I fixed the exhaust on each side. As you can see, there are attached to the chassis only with a friction pin and are locked on the engine. But it was not enough to prevent that they rotated under heavy playing. That is why I have used a construction with this part, which is placed recessed and underneath the elbow. This construction prevents the whole exhaust assembly to rotate, and as it is thin and dark, it is mostly invisible.


There are others small interesting building techniques that I will develop in the Design Secrets of this creation later. To finish with a global appreciation, I am very happy with the design of this creation. Even if the parts were mostly black which is useful for the design, the lack of connector and axle joiner, and even axle makes the design a bit tricky to avoid mismatched colors. But in my opinion, I succeeded. I am happy with the details on the engine, which looks powerful, and the use of certain panels to create interesting shapes, like the mudguard on the front bodywork and on the back of the bucket, but also this panel to create the rear shape. It gives a nice shape with a low profile vehicle which looks like making drag race !


This model uses only 842 parts on the 1359 parts which seems to be low, but this model is smaller than the original A model and have not a full bodywork, just a bucket bodywork, and open engine area. Despite that, it has classic but playable functions and nice looking with the lights on and several details, it is a great addition to the original model.

You can see some renders below, please note that this steering wheel is not available in Bricklink Studio so I have replace by a smaller one, only for rendering :

Pictures and Video


English spoken video version of this article (Design Secrets – Bucket Hot Rod on YouTube)

Specs : 32cm (L) x 18cm (W) x 12cm (H)

Building Instructions

As a B model, I have of course created the instructions, which are step by step high resolution computer generated instructions 300DPI for 132 pages, with partlist, flexible parts, white edge on dark parts, highlighted parts for each step (you can see preview in the galley below). Regarding the bill of material, as an alternate model, if you own the #42127 Lego set, you have all the needed parts. But you can checked the exact bill of material on Rebrickable and export in whatever format you want. The picturing bill of material are also visible in the instruction previews and included in the instructions.

Want to know if you can build the 42127 Bucket Hot Rod ? The model has been indexed to rebrickable, check it !

You can buy the instructions with the following button for 12€ (including 20% VAT). You can also buy other building instructions and get an automated discount, 15% off for 2 PDF, and 20% off for 3 PDF on the total). The automated discount is available for all the instructions for sale on nico71.fr.

See it on the shop

An alternate model of the LEGO Technic Set 42127 – Batmobile, as a Bucket Hot Rod. Features, steering connected to the steering wheel, rear wheel drive with fake V8 engine, opening doors, removable hard top, light bricks in the engine and on the rear light.

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 check your purchase history or 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 :

(4) Comments

    Congrats Nico, it is so good looking that it should be an A-model. Actually it is so good looking that it should be a real car 😉 It is a perfect hot rod, with a touch of modernity with the design of the doors and the back. Very nice use of the light on the motor, also visible thought the front grid.
    The 3D rendering are incredibly realistic, I spend almost a minute to wondering if it was a real picture or a computer rendering.
    I may want to buy the batmobil just to build your hot rod!

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