- BLDB Introduces TECHING “DM13” and Special 25% Off Campaign
- Product Overview: TECHING DM13
- Background of the Release
- Assembling a Straight-Four Engine from Components
- Crank and Timing Mechanism Interlock
- The Joy of Documenting the Process
- Rechargeable via USB for Repeated Observation
- Approximately 4 Hours of Assembly Experience
- Displaying the Metal Texture Upon Completion
- Distinctions within the Metal Engine Model Series
- New Product Launch Commemorative Campaign
- Product Specifications
- Set Contents and Safety Precautions
- Product Information
- About BLDB
- Company Overview
BLDB Introduces TECHING “DM13” and Special 25% Off Campaign
BLDB, operated by SHUEI NETWORK TRADING CO., LTD., has announced the release of the TECHING “DM13 Straight-Four Engine Model Assembly Kit (Upgraded Version).” This new product allows enthusiasts to assemble over 364 metal parts to create a functional straight-four engine model that operates via an electric motor.
To celebrate the launch of this new product, BLDB is offering a special promotion: customers can receive a 25% discount on all items in the metal engine model series by using the coupon code “NEWS25” at checkout. This campaign began on September 8, 2026. Details regarding the end date, stock availability, and eligibility can be found on the product pages and during the checkout process.

Product Overview: TECHING DM13
The DM13 model kit is designed for individuals interested in mechanical structures and hands-on DIY projects. It features over 364 metal components that are assembled to replicate the appearance and internal mechanisms of a straight-four engine. Unlike fuel-powered engines, this model is electric, running on a 500mAh lithium battery rechargeable via a DC 5V USB connection. The kit includes assembly tools and instructions, with an estimated assembly time of approximately 4 hours and a manufacturer-rated difficulty of 4 out of 5.
Product Page: https://bldb.jp/products/teching-dm13-l4-electric-engine-model-kit
Background of the Release
When selecting engine models, there are differences between static display models and those designed for assembly and observation of moving mechanisms. The TECHING DM13 is specifically engineered to allow users to build a straight-four engine structure piece by piece and then observe its movement electrically. BLDB aims to offer this product to those who wish to learn about mechanical structures in 3D, engage in tool-based DIY, or seek a display model that also demonstrates functionality. The electric operation eliminates the need for fuel management, providing a way to observe the synchronized movements of pistons, crankshaft, belts, and fans.

Assembling a Straight-Four Engine from Components
The DM13 kit accurately reproduces the exterior and internal mechanisms of a straight-four (L4) engine. Over 364 parts are assembled following the provided instructions, combining aluminum alloy and stainless steel components. The aluminum parts feature an anodized finish, creating a striking contrast between the blue body and silver metallic parts. During assembly, it is important to verify the orientation of parts, the tightness of screws, and the resistance of movable sections at each step. Once completed, activating the power source causes the motor to drive the crankshaft mechanism, belts, and fan. This model is intended for safe observation of internal movements rather than replicating the power output of a real vehicle engine.

Crank and Timing Mechanism Interlock
In a straight-four engine, the piston movement in each cylinder transmits power to the crankshaft. The DM13 model allows for a clear view of this intricate relationship. As the motor operates, the interaction between the crankshaft, timing gears, and belts can be observed. The model’s design ensures that the upper timing gear and belt, side pulleys, and front fan are visible from the exterior, offering insight into the engine’s internal workings.

The Joy of Documenting the Process
Assembling the DM13 is more than just putting parts together; it is an engaging process. It begins with sorting parts by number and then progressively building from larger components like the crankshaft and cylinders. Subsequently, timing gears, belts, fans, motors, and wiring are installed, with checks to ensure smooth rotation of movable parts. Finally, exterior components and the stand are secured, and after USB charging, low-speed operation is confirmed. Documenting each step with photos or notes can be beneficial for recalling which parts contribute to specific movements after completion. If assembly is paused, unused and used parts should be separated, and small components like screws stored in sealed containers. If the mechanism does not operate, it is advisable to check the battery level, belt position, screw tightness, and any interference between parts.
Rechargeable via USB for Repeated Observation
The model is equipped with a 500mAh lithium battery and supports DC 5V USB charging. The approximate charging time is 2 hours, providing over 30 minutes of operation on a full charge. Charging and operating times may vary based on the power source, room temperature, part resistance, and continuous operation conditions. It is important not to operate the model while charging and to follow the instructions for charging. As it does not require fuel, ignition, or exhaust systems, preparation for operation is simpler than with a real gasoline engine. However, due to movable parts, fingers, hair, clothing, or tools should be kept clear of the fan, belts, and gears when the power is on.


Approximately 4 Hours of Assembly Experience
The estimated assembly time is approximately 4 hours. This duration can vary depending on individual experience, time spent sorting parts, and breaks taken during the process. Before starting, it is recommended to prepare a bright, flat workspace with the instructions, tools, and parts laid out. Recording part numbers and installation locations for each step can facilitate resuming work if interrupted. The manufacturer rates the assembly difficulty as 4 out of 5. Handling small screws and metal parts requires precision, making it suitable for environments where detailed work can be undertaken at leisure.

Displaying the Metal Texture Upon Completion
With completed dimensions of approximately 158.5×117×182mm and a weight of about 1,747g, the model is sized for display on shelves or desks. If the movable parts are to be operated, sufficient clearance should be ensured around the fan and belts. The combination of the blue aluminum alloy body, silver stainless steel parts, and black belts and fans allows for observation of the mechanism from the front, sides, and top. To maintain its condition, the model should be kept away from direct sunlight and high humidity. If dust accumulates, turn off the power and gently wipe it with a soft, dry cloth.


Distinctions within the Metal Engine Model Series
BLDB’s metal engine model series includes electric models for observing movement, spring- or gear-driven models for mechanical inspection, and functional models that operate with fuel. The DM13 is an electric model that can be charged and operated repeatedly without fuel. It is suited for those who prioritize post-assembly operation and display in a single model, rather than the fuel management and outdoor operation of functional engines. The series page provides an overview of products differing in cylinder count, power method, assembly status, size, and accessories. Before purchasing, it is recommended to compare assembly time, installation space, power requirements, and target age.
Series Page: https://bldb.jp/collections/engine-models



New Product Launch Commemorative Campaign
The “NEWS25” coupon offers a 25% discount on all products in the metal engine model series, including the newly launched DM13. The series encompasses models with varying power methods and assembly difficulties, such as electric models for observing mechanisms, spring- or gear-driven models, and functional models that operate with fuel. Customers are advised to review the specifications and accessories on each product page before making a purchase. For instance, if the DM13 is listed at 82,105 JPY, applying the 25% discount would result in a calculated price of 61,579 JPY. The display of discount amounts, rounding, stock, and eligibility for combining with other campaigns will be prioritized as shown on the checkout screen. As other products in the series have different listed prices, the discounted amount will vary accordingly. Even if no end date is specified, the campaign may become unavailable due to changes in stock or sales conditions. Those considering a purchase are encouraged to check the specifications of their desired model and utilize the coupon code “NEWS25” while it is available. This campaign aims to provide a purchasing opportunity for readers comparing models in the series, in celebration of the new product launch.


Product Specifications
| Item | Specification |
|---|---|
| Brand | TECHING |
| Model Number | DM13 (Upgraded Version) |
| Reproduction | Straight-Four (L4) Engine |
| Drive System | Electric Motor Driven |
| Material | Aluminum Alloy, Stainless Steel |
| Surface Treatment | Anodized |
| Number of Parts | 364+ |
| Completed Size | Approx. 158.5×117×182mm |
| Completed Weight | Approx. 1,747g |
| Charging Input | DC 5V (USB) |
| Battery | Lithium Battery 500mAh |
| Charging Time | Approx. 2 hours (目安) |
| Operating Time | 30+ minutes on full charge (目安) |
| Assembly Time | Approx. 4 hours (目安) |
| Assembly Difficulty | ★★★★☆ (Manufacturer Standard) |
| Target Age | Refer to product page |
Set Contents and Safety Precautions
The kit includes one engine assembly kit, assembly tools, and an instruction manual. Information regarding charging peripherals, replacement parts, or additional tools should be confirmed on the product page at the time of purchase.
This product is an electric model that reproduces mechanical movements. Assembly and charging should be performed according to the instructions. During operation, keep fingers, hair, clothing, and tools away from movable parts such as the fan, belts, and gears. To prevent injuries from part edges or tool tips, use a bright, flat work surface. Store small parts in a location inaccessible to infants and pets. Discontinue use immediately if abnormal noises, heat generation, wiring damage, or battery swelling are observed.
Product Information
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Product Name: TECHING DM13 Straight-Four Engine Model Assembly Kit (Electric, 364+ parts, Upgraded Version)
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Brand: TECHING
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Seller: BLDB (Building Block)
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Product Page: https://bldb.jp/products/teching-dm13-l4-electric-engine-model-kit
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Metal Engine Model Series: https://bldb.jp/collections/engine-models
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Official Online Store: https://bldb.jp/
About BLDB
BLDB (Building Block), operated by SHUEI NETWORK TRADING CO., LTD., offers 3D metal puzzles, mechanical models, and powered models that provide enjoyment through metal part assembly via its official online store. The company aims to provide long-lasting hobby experiences, including preparation before assembly, part management during the process, and display after completion. Product specifications, target age, stock, and shipping conditions vary by model, so customers are advised to check each product page before purchasing.
Company Overview
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International Development Lead: SHUEI NETWORK TRADING CO., LTD.
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Business Activities: Sales of 3D metal models, mechanical puzzles, and DIY assembly kits.
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Inquiries: Please contact us via the inquiry form on the official online store.
All specifications, prices, stock, and campaign details in this article are based on information available on the official online store at the time of publication.
Assembly time is an estimate and may vary depending on the work environment and experience.
*The images included in this article are completed images obtained from the BLDB official product page. Actual colors and light appearance may vary depending on the monitor and usage environment.

