BLDB Launches Summer Bonus Sale, Featuring 1/12 Electric Turbofan Engine Model ‘DM121’

Bringing the Inside of an Aircraft Engine Within Reach

Turbofan engines are crucial for aircraft propulsion, with numerous interconnected components such as fans, shafts, and turbines. The “DM121” is a 1/12 scale metal model that meticulously reproduces these internal mechanisms, which are typically hidden from view in a complete aircraft.

This model is based on a dual-spool system, where various parts are arranged around multiple rotating axes. Its cutaway design provides an unobstructed view of the interior. By assembling parts sequentially, users can understand their placement and connections. This hands-on approach offers a deeper comprehension of complex structures that might be difficult to grasp from theoretical explanations alone.

Assembling Over 300 Metal Parts Module by Module

The DM121 comprises more than 300 parts, primarily crafted from aluminum alloy and zinc alloy. The assembly process involves building the fan, shaft, casing, and internal units in stages, eventually integrating them into a complete engine model. The difficulty level is rated 3 out of 5, with an estimated assembly time of 2 hours or more. The modular design simplifies the process, allowing users to follow the instructions and work at their own pace. A complete set of assembly tools is included, though completion time may vary based on individual experience. The model’s substantial weight of approximately 2.8kg, derived from its metal components, and its industrial silver finish are notable features, providing both a satisfying build and an impressive display piece for a study or desk.

The Assembly Journey Begins Upon Opening the Box

The kit includes all necessary engine model parts, assembly tools, and an instruction manual. It is advisable to review the parts against the instructions before starting, as each component has a distinct shape and function, which can streamline the assembly process. For precision models, careful attention to detail, such as checking the orientation of parts and the tightness of screws at each step, is more crucial than rushing to completion. A well-lit, flat workspace with ample room for parts, tools, and the manual is recommended. Using a tray for small parts and removed screws can help prevent loss. The process of gradually combining individual components into the elongated form of an aircraft engine offers a unique sense of accomplishment, distinct from simply purchasing a finished product. Taking breaks to admire the progress is also a rewarding aspect of precision modeling.

Electric Rotation After Completion: Observe the Connection of Assembled Parts

The model incorporates an electric motor and a 3.7V, 800mAh rechargeable lithium battery. Once assembled, powering it on initiates the synchronized rotation of the fan and internal mechanisms, bringing the user’s assembled parts to life. Charging is done via a DC 5V compatible USB cable, taking approximately 2 hours for a full charge, which provides about 30 minutes of continuous operation. Beyond its visual appeal, the model allows for a clear understanding of how power is transmitted, offering ongoing learning even after assembly. It is important to note that this product is designed as a display and educational model, reproducing the structure and rotational movement of a turbofan engine; it does not feature combustion capabilities or generate thrust for aircraft propulsion.

Cutaway Structure Ensures Internal Movement is Visible

Unlike many finished models where internal components become hidden once the exterior casing is attached, the DM121’s cutaway structure allows for simultaneous viewing of both the outer silhouette and the inner mechanisms. Observing the flow from the large front fan to the central shaft and internal units reveals their alignment along a single axis. By comparing the model in its powered-on and stopped states, users can identify which parts rotate and which provide structural support. The primary benefit of the DM121 is not just its operation, but the integrated experience of “assemble, observe, understand,” allowing users to reinforce their knowledge of part relationships by seeing them in motion.

Approx. 31cm in Length: A Desktop Model Allowing Observation of Internal Structure

The completed model measures approximately 312×167×188mm, a size conducive to detailed observation and suitable for display in a study or collection area. The large fan is visible from the front, while the shaft and internal units are apparent from the side, offering varied perspectives. This model is an excellent addition for aircraft enthusiasts and model collectors, and also serves as a thoughtful gift for students and engineers interested in mechanical structures. Designed for individuals aged 16 and above, this mechanical model provides three distinct pleasures: assembly, operation, and structural observation.

Enjoyment for Specific Times and Individuals

For those who want to focus on one thing during summer vacation

Even with extended holidays, time can often pass by without engaging in focused activities. Model making, which requires meticulous attention to parts, tool usage, and observing the evolving shape, offers a distinct way to spend time. The DM121’s estimated assembly time is 2 hours or more, though actual time may vary based on experience. It is recommended to allocate ample time without rushing. The model can be completed in a single day or over several days by tackling individual units.

For those who love aircraft and mechanical structures

While passenger aircraft are a common sight, opportunities to observe the intricate internal mechanisms of their engines are rare. The DM121, though not replicating the performance of a real engine, allows for hands-on observation of the fan, shaft, and internal unit configurations. It serves as an excellent starting point for those moving from admiring aircraft aesthetics to exploring their underlying structures, or as a new challenge for individuals who have experience with automotive engine models. The model caters to various levels of interest.

For those who want to give the experience of completion, not just the ‘thing’

A model kit is, by nature, incomplete when received. The recipient invests time in assembling parts and verifying operation to bring it to completion. This offers a unique gift experience that includes the process of creation and a sense of achievement, unlike simply presenting a finished product. It is a suitable gift for aircraft enthusiasts, craftspeople, mechanical engineering students, and those involved in manufacturing, for birthdays or anniversaries. The target age is 16 and above. When gifting, it is advisable to inform the recipient about the small metal parts involved and the need for a stable workspace.

Choose by Size and Depth of Challenge, Even for the Same Turbofan

BLDB’s engine model series includes other turbofan-themed models in addition to the DM121. The ideal choice depends on factors such as available display space, assembly time, and desired part count. The DM121, at 1/12 scale with over 300 parts, an estimated assembly time of 2 hours or more, and a difficulty rating of ★★★☆☆, is approximately 31cm long and suitable for those new to metal aircraft engine models. For those seeking a larger scale or more intricate projects, options include the 1/10 scale DM135 with over 600 parts, or a dual-spool turbofan model with over 1000 pieces. For individuals interested in the basic movements of automotive engines, single-cylinder and inline-four-cylinder models are also available. Before purchasing, review the part count, completed size, assembly time, drive method, and target age listed on each product page. Considering the display location post-assembly helps ensure a fulfilling experience from build to exhibition.

Four Points to Check Before Assembly

1. Work Space: Beyond the finished size, adequate space is required for spreading out parts, tools, and the instruction manual during assembly. Ensure a bright, flat desk that allows for safe storage of parts during breaks.
2. Working Time: The “2 hours or more” assembly time is an estimate. First-time precision model builders or those who prefer a meticulous approach may require more time. Selecting a day free from time constraints will enhance the enjoyment of the process.
3. Charging and Operation Check: After assembly, charge the model using a DC 5V compatible USB cable as per instructions. Before powering on, verify the correct attachment of all parts and wiring according to the manual.
4. Target Age and Small Parts: The model is intended for individuals aged 16 and above. Due to the presence of small metal parts and tools, ensure assembly and storage are in locations inaccessible to infants.

Frequently Asked Questions about DM121

Q. Is this a finished product?
A. No. It is a DIY kit that requires the purchaser to assemble over 300 parts. The kit includes model parts, assembly tools, and an assembly manual.

Q. Is it an actual jet engine that burns fuel?
A. It does not have combustion functions or generate thrust. It is a display and educational model that reproduces the rotational movement of the fan and internal mechanisms using an electric motor.

Q. Can a beginner assemble it?
A. The difficulty level is rated 3 out of 5, and the assembly can be done module by module. However, as it involves handling small metal parts, it is important to refer to the instructions and ensure ample time and a suitable workspace.

Q. How long does it operate after completion?
A. The charging time is approximately 2 hours, and the continuous operation time on a full charge is approximately 30 minutes. This may vary depending on the usage environment and battery condition.

Q. How much space is required?
A. The completed size is approximately 312×167×188mm. When installing the model, ensure sufficient surrounding space for operational checks and maintenance.

Q. How can I purchase it at the sale price?
A. Add eligible products to your cart and enter the coupon code “SUMMER20” during the checkout process. Please confirm that the discount has been applied before finalizing your order.

Summer Bonus Sale Overview

• Campaign: Summer Bonus Sale

• Eligible: Selected products on the BLDB official online store

• Discount: 20% OFF from the displayed price

• Coupon Code: SUMMER20

• How to Use: Add eligible products to your cart and enter the coupon code during checkout.

• DM121 Regular Price: 59,543 JPY (tax included)

• DM121 Price after coupon: 47,634 JPY (tax included)

• Campaign Page: https://bldb.jp/collections/bonus-sale

The campaign’s end date will be announced on the official online store. Content may be subject to change or termination without prior notice. Sales of eligible products may conclude once stock is depleted. Shipping costs will be displayed during checkout. For details on combining with other discounts or benefits, please refer to the checkout screen.

New Member Benefits Also Available

The BLDB official online store also offers a 15% discount automatically applied to the first order for new members, with no coupon code required. For eligibility conditions and compatibility with other discounts, please check the checkout screen.

Product Overview

• Product Name: 1/12 Electric Dual-Spool Turbofan Engine Assembly Kit DM121

• Model Number: DM121

• Scale: 1/12

• Number of Parts: Over 300

• Material: Aluminum alloy, Zinc alloy

• Completed Size: Approx. 312×167×188mm

• Weight: Approx. 2.8kg

• Drive Method: Electric motor

• Battery: 3.7V・800mAh rechargeable lithium battery

• Charging Method: DC 5V USB charging

• Charging Time: Approx. 2 hours

• Continuous Operation Time: Approx. 30 minutes on full charge

• Estimated Assembly Time: 2 hours or more

• Difficulty: ★★★☆☆

• Target Age: 16 years and older

• Accessories: Complete set of engine model parts, complete set of assembly tools, assembly manual

• Regular Price: 59,543 JPY (tax included)

• Price with “SUMMER20” coupon: 47,634 JPY (tax included)

• Product Page: https://bldb.jp/products/scale-build-your-own-cutaway-turbofan-engine-model-building-kits-dm121

Prices, stock, and campaign details are accurate as of August 13, 2026. Please refer to the product page for the most current information.

BLDB Engine Model Series

BLDB offers a range of precision models inspired by automotive and aircraft mechanisms, including single-cylinder, V2, inline-four, V8, V12, radial engines, turboshaft, and turbofan models. Each model varies in part count, assembly time, and drive method, allowing customers to choose based on their interests and experience levels, from beginners to seasoned builders seeking complex challenges.

• Engine Model List: https://bldb.jp/collections/engine-models

About BLDB (Building Block)

BLDB is a specialized brand dedicated to 3D metal puzzles and precision mechanical models for adults. The brand aims to convey the beauty of machinery and the richness of hands-on creation through immersive assembly experiences and products that offer continued enjoyment of structure and movement even after completion.

• Overseas Operations: SHUEI NETWORK TRADING CO., LTD.

• Official Online Store: https://bldb.jp/

• Contact: info@bldb.jp

Notes

• This product is not an actual engine for aircraft. It lacks combustion functions and thrust; it is an assembly model that reproduces the rotational movement of the mechanism via an electric motor.

• The product involves small metal parts and tools. Please adhere to the target age and safety precautions, and ensure assembly is carried out in a stable workspace.

• Product specifications, accessories, and appearance are subject to change without prior notice.