After the success of our first article on the new ‘FX Engines’ brand, we’ve once again teamed up with it’s creator Juraj Hudy to bring you a level of access and detail on the production side never seen before, this is a must read for any true ‘RC nerd’!

Before you embark on this adventurous read, don’t miss out on the story behind the formation of FX Engines, how long the projects been in the making and one of the key features that sets it apart immediately from other 3rd party engine brands – they are a true manufacturer, not a rebadged engine. Read the most detailed article on the production process of a top of the line RC Car engine.

Hit ‘More‘ to start the epic read!




3D Design:

State of the art 3D modeling software has been used to ensure that all of the engine components and their respective tolerances mate perfectly in order to ensure flawless assembly.

Data management:

All versions of all drawings and 3D models are stored in an SQL database with detailed records of each version of the file, including the name of each designer responsible for making a change. This allows us to maintain a detailed history of the ongoing development in order to know the ‘who, what, when, where and how’ for each change in order to maintain the most favorable features during the development process.

Work Flow process:

All drawings, models and production programs are subject to a review and approval process from the main project designer, designer of the part and production manager. Without the approval of all the three persons a drawing, model or manufacturing program will not be released to the next step of the work process.

Mould design:

All of the moulded and cast components are produced with moulds that have been fully engineered, designed and produced in house using specialized Mould Designer 3D software. The thorough FX Work Flow Process is followed to ensure superior quality.


Mould Flow check:

Prior to final approval of the moulds, special Mould Flow software is used to simulate the moulding or casting process. The software virtually injects the composite, rubber or alloy to simulate the production process and determine areas where the material does not optimally flow, which could result in a weakness. This allows FX to maintain superior quality by handling and understanding all steps of the production process and to change in advance any details as necessary in order to ensure flawless final product.


Programs for machines:

Once final design of all parts are approved and FX Workflow Process approval has been completed, the engineers upload their manufacturing programs into the same SQL database for reference, so again all the versions of all programs are stored and recorded. All of the machines in the manufacturing process are connected to an internal network and only approved manufacturing programs may be downloaded and used for production.


FX Engines production:

Mould manufacturing:

Once the mould is released into production all parts are manufactured in-house. The highly trained staff at FX has vast experience in mould manufacturing and finishing and take great pride in their craft.

To produce a mould for casting is extremely demanding because the mould needs to be extra large but still maintain incredibly tight tolerances. The selection of the proper material for caste mould production is critical and the heat treatment procedures are very specialized. The mould must be resistant to the extreme temperatures of the melted aluminum which exceeds 690-700°C. The heat treatment of all the mould parts is done at above 1000°C (over 1800 Fahrenheit) which only few specialized companies are capable of applying.

Mould electrode production:

The 3D CAD model of the finished part is used to generate the program for the electrical discharge machining (EDM) electrode. A specialized 5-axis milling machine precisely is then used to produce the electrode component. A craftsman then hand polishes the electrode to achieve the desired finish.


Moulding shape production:

The EDM electrodes are used on specialized Swiss machines to create the mould cavities.

mouldshape1 mouldshape2

Moulding holes production:

All holes and openings of the mould are held within a tolerance of 0.001mm.

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Moulds machining:

The housing of the mould and all of the required pins and inserts are machined using high-quality CNC milling machines and are manually ground and hand finished for a perfect fit.

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Mould assembly:

An average mould consists of nearly 150 different parts which are manually assembled and all hand finished during assembly for a very precise fit.


Moulding of composite parts:

All composite parts are moulded using German moulding machines. The composite mixtures are a proprietary FX blend that ensures the required strength and rigidity while maintaining just enough flex to assure durability.

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Die casting:

FX Engines is one of the very few companies in the world with their own in-house die casting technology. All of the cast aluminum components are die cast under pressure using high precision Italian die casting machines.


Vacuum casting:

Vacuum is applied to the mould cavity during the casting process to help the air to be removed, eliminating internal bubbles or voids from the final product. . The vacuum casting procedure also helps the melted aluminum to flow into the mould faster which again helps to increase the quality of the cast product.

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Robotic melting furnace:

The aluminum ingots are melted in robotic furnace which loads automatically the melted aluminum into the die casting machine.

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Machining of die casted products:

All die cast products such as the crankcase, cover and carburetor are additionally machined using high precision German 5-axis CNC machines. The machines use two large pallet tables that can hold up to a total of 40 crankcases, while the fully automated machine uses its battery of 60 different tools to finish the components, while also performing quality checks with a special laser equipped robot and self-adjusting to ensure that the tight tolerances are maintained. Special parts which require milling from all sides such as carburetors and engine cases are all machined at this robust ultra precise machine.

machining die cast

Milling production of large diameter aluminum parts:

All of the aluminum parts are machined on precise German CNC machines. Each part has a specialized fixture in which the pieces are manually mounted prior to milling. After the machining process, every part is removed, measured and inspected to assure that it meets the exacting FX Engines standards. Only diamond cutting tools are used in order to ensure the quality and precision of cut required by FX Engines. Specialized laser sensors are used to monitor the cutting tools to compensate for wear and maintain the quality of cut.


Milling production of small diameter aluminum parts: 

The smaller diameter aluminum parts are machined on a similar German CNC machine, however the smaller machine allows for 5 axis control allowing for complete machining without the need to re-fixture the parts.

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Milling production of brass parts:

To produce parts like sleeves requires a very special 5-axis milling machine which allows milling from all the sides. For this particular production a customized German machine was installed with special software and custom produced tools and holders. To achieve highest quality the machine is specially equipped with a 24 000RPM spindle. This machine is used exclusively for the production of sleeves.

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Cutting production of steel parts:

All of the steel parts are CNC machined using the most precise German machines, the most precise and expensive machines of their kind. The ultra robust construction allows these machines to reach and hold manufacturing tolerance of 0.002mm throughout the production run.  The Traub machines feature 11 axis control, which allows production in two spindles with two revolving tool holders and two linear supports with rotating units, without requiring human interaction, ensuring ultra-precise control. This machine is used for special steel parts which require repeatable ultra high precision of tolerances and surface finish such as crankshafts or carburetor needles. Thanks to the repeatably tight tolerance of all carburetor parts, all FX carburetors are exactly the same so the carburetor setting at different engines are all the same.


Cutting production of large diameter aluminum parts:

All billet-produced aluminum parts are CNC machined on German machines. The large parts such as the engine head are produced on a large 11 axis machine with 2 spindles and 3 revolving tool holders which allow two parts to be manufactured at the same time due to the extreme flexibility of this equipment. The automatic material loader holds bar material up to 65mm in diameter and up to 4m in length.

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Cutting production of small aluminum parts:

All of the smaller diameter aluminum parts, such as parts for carburetor, are produced using Italian and German 8-axis CNC machines. All the machines have 2 spindles and linear supports with fixed and rotating units which allow cutting and milling at the same time.

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Grinding may sound like an easy operation but the opposite is true. Precision grinding is a crucial part of the manufacturing process as it brings the parts to their final dimensions and tight tolerances and repeatability are critical. To achieve repeatable tolerances of 0.001mm, an industry-leading Swiss CNC grinding machine from was installed. The machine features two grinding drums, one which prepares the required dimension, and the second one which brings the part to the final dimensions, all fully automatically. The robotic machine measures every single product and adjusts the program and settings appropriately to maintain the target diameters and super smooth finish demanded by FX Engines. Special parts which require the tightest tolerances are ground using this machine such as crankshaft, outside diameter of pistons and inner diameter of sleeves.

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 Sand blasting:

The crankcase, carburetor, rear cover and engine head are all sand blasted. To ensure the quality all engine heads are individually manually blasted.


Color coating and hard coating:

The hard coating of the aluminum parts, as well as the color coatings are all processed using a highly advanced coating line, featuring 20 baths and a fully automated process that allows 3 batches of product to be processed at the same time. The coating process is very precise and requires strict controls to manage the many factors that can affect the chemical reactions involved.

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During the coating process all details must be considered and process adjusted which includes: air temperature, temperature of every bath, PH of every bath, size and surface of every part and batch, type of material used, color and chemicals mixtures used, thickness of final structure to be achieved, amount of batches already run, etc. Again, this is an internal process at FX Engines to maintain our strict standards of quality control.

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Laser engraving:

The fully automated laser engraving process is performed on German CNC engraving machines with rotating tables for precision and clarity.


Hone machine:

A very precise, old school American honing machine is used for manually hand-finishing of holes in the products. Every hole and opening are manually calibrated and the surfaces polished until they meet the required specifications. All parts where the fitment is critical such as sleeves as well as holes on conrod shafts, pistons and carburetors are all manually and individually honed.



 Cleaning machine:

Due to the tight tolerances of a nitro engine it is extremely important that all parts are free from debris. After each step of the manufacturing process, all parts are cleaned in a fully automatic cleaning machine and oiled to protect against corrosion.

Before assembly all parts are once again cleaned, but this time in small batches using a special ultrasonic machine to remove any remaining debris prior to finished assembly.



FX Engines unmatched perfection:

During production, the sizes and tolerances of all important and key parts of each engine are measured and recorded. All of the main parts have serial numbers engraved and all of the important sizes, tolerances and information about the production of the part are recorded and stored.


The surface roughness, finish and treatment on crucial parts such as crankcase, crankshaft, sleeve, piston, pistons inserts, carburetor, sliders, are also extremely important and all are individually measured and recorded.

A birth certificate is issued for every engine where all of the serial numbers of the main parts are recorded and it is possible at any time to trace the roots of every part back through production processes to its absolute beginning including information on which batch of material was used, what manufacturing program was used and by whom and when the part was produced. FX fully stands behind every single part and every single engine produced.


FX Engines advanced treatments:

The heat treatment and hardening process of all the parts is one of the most important processes which has significant influence on the reliability and life time of all the parts. The type of material and all the metallurgic processes involved in the treatment all effect the strength, durability and wear resistance of the parts. All of the treatment processes were developed by Dipl. Eng. Juraj Hudy for his proprietary steel. Knowledge acquired in over 30 years of experience was utilized for developing and implementing the appropriate procedures for all the engine parts. Every single batch is tested, measured under a microscope, sampled and the data is recorded and archived.

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 FX Engines artistic assembly:

All the artwork and magic made in production is backed up with craftsmanship at assembly. The artisans who assemble FX Engines have been with the team since the very beginning. The skills of these key craftsmen have been perfected over the years during hundreds of prototypes that were assembled, disassembled, inspected and refined. These years of experience have trained them to know exactly which areas are crucial to ensure that to achieving the superior quality that their pride of workmanship demands.

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FX Materials used:

FX uses only the most premium European materials for every single part. There is no compromise with any of the material, tools and equipment used during the production, manufacturing and assembly process.


All aluminum parts such as head, conrod, internal carburetor parts, etc are machined only from the most durable Swiss 7075 T6 aluminum materials. Every new batch of the raw material is measured and inspected upon arrival to ensure it meets the highest requirements.


To choose and use the proper material for the pistons is extremely important for the performance of the engine because the pistons experience extreme forces inside the sleeve are subject to heat expansion. There are plenty of material choices from which dozen of different materials were long term tested before the final one was chosen. All the FX pistons are manufactured from bars of Silicium alloy by machining, milling and grinding which ensures consistent material properties over the entire cross-section of the piston.



The only logical choice for all of the steel parts such as crankshaft was to use nothing other than the world renowned Hudy Steel™. This special steel is custom produced based on the secret formulation developed by Dipl. Eng. Juraj Hudy more than 30 years ago and used successfully for decades in RC cars in the most demanding applications. This unique formula of steel production and hardening processes has remained unchanged. Every new batch of steel is randomly measured and a sample is hardened to confirm the parameters meet the very strict requirements on the specifications of the steel and the labeled samples are stored & archived.



The sleeves are machined from high tensile brass.


Composite mixtures:

There are countless manufacturers and formulations of different composite materials in the market. To choose the right one for the particular part requires years and years of experience in this particular field. Each of these composites can then be additionally mixed and the knowledge of the proper composite mixtures is a highly specialized field. FX uses specialized and experienced masters with more than 20 years of experience in mixing of composite mixtures specifically blended for RC car applications. All of the raw composites are manufactured in Germany or Switzerland and all the mixtures are blended in-house using proprietary recipes to ensure low wear, yet sufficient strength and durability of all the moulded parts.



Like the composite materials there are also plenty of aluminum ingots with various material compositions. The proper aluminum for the crankcase and carburetor is one of the most important features of the properly and reliably working engine. The die-casting aluminum can be mixed like the composite materials and there is almost an infinite amount of variations that can be achieved and the main aim is to look for such a material which will be ideal combination of material heat expansion, heat sink, stability and hardness.


It took the R&D team more than 6 years to test several dozens of different aluminum die-casting mixtures to find the proper one. The final mixture is a secret recipe of a mixture of various German and Italian ingots which are melted in a given and specified ratio to specified temperature and injected under specific pressure and vacuum….an artform of its own.


All the development, testing, implementation of new technologies, setting and fine  tuning of new technological manufacturing processes, development of all of the materials and their associated treatments have all been tuned to absolute perfection. This has been an incredibly time consuming process, taking more than 6 years to reach the point where the extreme targets for quality, reliability and performance are met. We have dedicated our passion for perfection to the development of this new product line, and now it is ready for you to enjoy. The wait is over, FX Engines are here.

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