Frequently Asked Questions

Metals deform permanently before they break, and that is a visible warning. Composites do not behave that way — but this does not mean they are unpredictable.

In a composite, damage is not a single event but a gradual chain: first matrix cracks, then separation between layers (delamination), and only at the end fiber failure. The structure usually begins losing stiffness long before the fibers break, and that loss is measurable.

This is why the aerospace standard is based not on "no damage shall occur" but on "the structure shall complete its mission when damage occurs". Tulkas parts are built with this damage-tolerant design philosophy: critical load paths are reinforced, and design stress levels are set on the safe operating band rather than on the ultimate failure value.

This is the most legitimate concern in the industry, and it has a name: BVID — Barely Visible Impact Damage. An impact that is almost imperceptible from the outside can leave delamination in the inner layers.

The answer lies in inspection:

• Non-destructive testing (NDT): Ultrasonic scanning maps internal delamination
• Thermography: Makes sub-surface damage visible through differences in thermal behavior
• Tap testing: Provides a fast preliminary check under field conditions

More important is the design side: zones where impact is expected are sized so they can still carry load with BVID-level damage present. On critical parts Tulkas delivers the inspection protocol as part of the delivery and defines field inspection criteria together with the customer.

Yes — but it requires a different discipline than metal repair. It cannot be welded; the damaged zone is opened up in steps (scarf repair) and new layers are placed in line with the original orientation and cured.

The honest limit is this: a fast repair performed under field conditions will not reach factory quality. For critical structural parts, therefore, the right approach is usually modular replacement rather than repair. Tulkas segments the part around this reality during design: zones likely to be damaged are separated so that the whole airframe does not have to be replaced.

This is the least discussed but greatest advantage of composites. Aluminum alloys have no fatigue endurance limit; even under a sufficiently low stress, cracks will initiate after enough cycles. Carbon fiber composites, at properly designed stress levels, show far superior fatigue behavior.

On any platform where vibration is continuous, this difference translates directly into maintenance schedules and part replacement costs: propellers, motor mounts, UAV arms, and structures carrying wave loads on marine platforms. For a metal part, "when will it be replaced" is a calendar question; for a properly designed composite part, that calendar stretches considerably.

The honest answer: not as much as you expect from a direct material swap. If you produce the geometry of a metal part identically in composite, the gain stays limited — and in some cases you even lose.

The real gain comes from redesigning the part for composite: turning a structure of 20 parts and 100 fasteners into a single-piece monocoque body, variable laminate thickness following load paths, and the use of sandwich panels. The gain usually accumulates not in individual parts, but in eliminated fasteners and reduced assembly complexity.

This is why Tulkas does not say "let us copy your part"; it first asks for the load cases and the mission profile. Project-specific weight saving figures are shared at the quotation stage.

Yes — and if ignored, it becomes a problem that affects the entire platform. Carbon fiber is electrically conductive and attenuates signals. Unlike aluminum, being only "partially" conductive makes the situation even more complex.

The solution is not to avoid composites but to design windows for the antennas: radio-transparent panels reinforced with glass fiber or kevlar are used in the relevant zones. The same approach is the basis of radome structures in defense. Grounding and EMI shielding architecture must also be planned during design.

Tulkas addresses antenna and sensor placement at the beginning of airframe design rather than at the end; a window opened later strains both the structure and the program.

The difference comes less from strength than from the ability to hold shape. If a propeller cannot maintain its designed geometry at full load, the efficiency figure on paper never materializes.

Injection-molded plastic propellers bend and twist under aerodynamic load at high RPM; effective pitch drops, thrust decreases, and the motor draws more current. The high stiffness of carbon fiber limits this deformation. The second gain is in vibration: reduced vibration directly affects both motor bearing life and camera/sensor image quality.

But let us state the limit as well: for a one-off prototype, tooling investment may not be economical. The real return of a composite propeller appears in serial use, with a geometry optimized for the platform's mission profile.

Composites carry distributed loads excellently; under point loads, correct detail design is essential. A bolt clamping directly onto a composite plate can crush the layers and cause local damage.

The standard engineering solution is metallic inserts: the load is spread over a wide area before being transferred into the composite structure. There are two critical details here — correctly sizing the insert, and insulating against galvanic corrosion (where carbon fiber contacts aluminum, the metal corrodes over time; an insulating layer goes in between).

This is not a weakness of composites but a core discipline of composite engineering. Tulkas plans insert placement at the start of design, together with the load paths.

For such parts composite is not only safe but often the preferred solution — because the problem is three-dimensional: withstanding internal pressure, holding the internal diameter for firing accuracy, and staying light enough not to burden the soldier or the platform.

On cylindrical geometries, filament winding makes it possible to place fibers exactly along the direction the pressure loads follow. The result is a structure that is markedly lighter than its metal counterpart yet dimensionally highly stable. Weight here is not a comfort matter but a matter of firepower: it determines how many systems can be carried into the field.

Tulkas designs defense composite parts and rocket canisters to satisfy these three criteria simultaneously. The applied test and acceptance criteria are defined on a per-project basis.

Composites are inherently non-magnetic and their electromagnetic behavior differs from metals. This opens room for the designer on platforms requiring low signature:

• Radar: Different reflection behavior compared to metallic surfaces; the form freedom composites offer also allows complex geometries that reduce radar cross-section to be produced as a single piece
• Magnetic: A decisive advantage on marine missions requiring magnetic signature control (especially mine countermeasures)
• Acoustic: Superior vibration damping reduces propagation of engine and drivetrain noise through the structure

An honest note: composite alone does not provide "invisibility". Signature management is the joint result of material, geometry and coating. Composite is an enabler in that equation, not a solution on its own.

In defense programs the supply chain itself is a risk item, as much as technical capability. For critical parts sourced abroad, supply interruption, delivery delay and export restriction risks can halt an entire program.

Tulkas's approach comes down to three headings:

• Domestic design and domestic serial production: Keeping the process from design to production within the country
• Confidentiality: Working under a non-disclosure agreement (NDA) for project information, technical data and customer designs
• Traceability: Full documentation from the material batch used through to the production record

Tulkas holds the required quality certifications and facility security infrastructure.

Composites do not undergo electrochemical corrosion in salt water. The greatest enemy of metal marine components' service life — corrosion — is simply not an agenda item for this material.

The real question, however, is water absorption behavior, and it deserves an honest answer: under long-term immersion the resin system takes up a limited amount of moisture. This is not a sudden failure but a measurable and predictable reduction in mechanical properties. The design accounts for that reduction; in addition, appropriate resin selection, gelcoat and barrier layers seriously limit absorption.

At sea the real cost is not the price of the part but the endless maintenance cycle corrosion brings. Tulkas designs marine and subsea composite components to break that cycle.

Yes — and this is the most frequent mistake in marine projects. Carbon fiber is electrically conductive, and when it contacts metals such as aluminum it forms a galvanic couple. Once an electrolyte (sea water) enters the picture, accelerated corrosion begins on the metal side.

The solution is a known and applicable engineering discipline:

• Selecting compatible metals (stainless steel or titanium preferred)
• A glass fiber or insulating barrier layer at the contact surface
• Correct sealing and insulation detailing

If this detail is not solved during design, it is expensive to compensate for in the field. Tulkas defines hybrid joint details in the first design round.

For cylindrical structures under pressure, the critical risk is not crushing of the material but buckling — that is, the structure losing stability. This is determined by geometry, wall thickness and stiffness distribution far more than by material strength.

Composite offers two advantages here: the ability to optimize the laminate architecture separately for the hoop and axial stresses pressure creates, and reaching the same stiffness at lower weight. In subsea systems, weight means buoyancy budget and energy consumption directly.

The critical point is this: every depth profile requires a different design. Depth-rated parts are not selected from a catalogue — target depth, safety factor and cycle count must be defined from the outset.

In a foil, performance depends on the section geometry being preserved under load. A foil that bends or twists under high hydrodynamic load loses its designed angle of attack; the lift-to-drag ratio drops and the promised efficiency never materializes.

The high specific stiffness of carbon fiber is decisive here: achieving the same stiffness in metal would mean an unacceptable weight increase. Surface quality also affects drag directly, and composite manufacturing makes it possible to obtain high surface quality straight out of the mold.

Tulkas defines the design target for foil structures in a single sentence: a foil that holds its shape under load holds its efficiency.

Because the comparison is usually made on the wrong line item. Most of composite cost sits not in material but in tooling and engineering, and those two items are divided by volume. That is why composite is expensive at low volume and becomes competitive as volume rises.

Part price alone also does not represent total cost:

• Eliminated fasteners and reduced assembly labor
• The end of periodic maintenance driven by corrosion
• Extended replacement intervals thanks to superior fatigue life
• Weight saving converted into fuel, battery or payload

The right question is not "how much is this part?" but "what does this part gain me?".

Single-piece production is possible for R&D and prototype projects; serial production pricing is tiered according to volume. Volume is the single most decisive variable in price — which is why sharing the targeted annual quantity at the quotation stage is critical for the right method and the right price.

Tooling cost is usually stated as a separate budget item from production when the project is costed, and is reflected in the first invoice. Ownership of fully paid molds belongs to the customer. Tulkas takes responsibility for storing the molds securely at its facility, maintaining them regularly, and keeping them ready for production cycles.

In composite projects lead time is not a single figure; it consists of three separate stages: design and analysis, mold production, and part production and cure. The biggest variable driving the schedule is usually not production but design revision rounds.

This is why Tulkas gathers requirements in detail from the outset: an under-defined requirement costs weeks later on. In a typical structural part project, the time from design approval to the first prototype ranges from 4 to 12 weeks depending on the scale of the project.

Products are made to order, using tooling-based production matched to the dimensions, quantity, and configuration you share.

Yes. Dimensions, thickness, and configuration can be adapted to your project; share the technical details via the contact form.

Product type, use case, target dimensions, quantity, and a CAD/technical drawing if available.

Used for UAV arms, robotic systems, marine applications, and structural frames; produced in custom diameters, wall thicknesses, and fiber orientations with project-specific cutting and machining.

Used for UAV frames, mechanical parts, and structural panels; produced in various thicknesses with twill and plain weave options, in a homogeneous structure suitable for CNC machining.

Carbon fiber masts, fuselages, and wing sets for wing foil and kite foil use are developed with hydrodynamic analysis support, using a modular connection system for different riding styles.

Designed around motor and platform data using an in-house design program and OpenFOAM-based flow analysis, validated with an in-house static thrust test; static and dynamic balance control supports the transition from prototype to serial production.

CNC-cut for racing, freestyle, and industrial FPV platforms, with an impact-resistant arm design optimized together with project-specific geometry and dimensions.

Both. Design and engineering, tooling, manufacturing, and the prototype-to-serial-production path are handled as one connected workflow, not separate handoffs.

Method selection depends on the part: hot-press molding, vacuum infusion, vacuum bagging, hand layup, SMC, BMC, post-cure, and vacuum-cast polyurethane are the processes in active use. The right one is chosen based on geometry, tolerance, and volume, not applied uniformly to every part.

They are treated as one workflow, not separate handoffs: design defines the geometry, tooling makes it repeatable, manufacturing executes it with a verified process, and the prototype-to-serial-production step controls the transition to volume.

Not currently. Our active production methods are hot-press molding, vacuum infusion, vacuum bagging, hand layup, SMC, BMC, post-cure, and vacuum-cast polyurethane. If a project genuinely requires autoclave or RTM, that is scoped and disclosed openly rather than implied.

Geometry, tolerance expectations, surface requirements, structural targets, and production volume are reviewed together before a method is locked in. The same part can be produced differently at prototype stage versus serial production.

No. Hot-press molding, vacuum infusion, vacuum bagging, hand layup, SMC, BMC, post-cure, and vacuum-cast polyurethane each fit different geometries and volumes; the method is matched to the part, not applied as a default.

Both, where relevant. OpenFOAM-based flow analysis and in-house propeller design software support propeller and flow-critical geometry work; structural evaluation is scoped to what the part actually needs.

Both. We support early-stage geometry definition as well as manufacturability review and refinement of an existing design; the entry point depends on where the project actually is.

During design. Interfaces, laminate strategy, and tooling logic are reviewed together from the start, not handed off as a separate step once geometry is frozen.

Not as a general figure — these depend on the specific part and tool. They are confirmed during the tooling review for your project rather than quoted generically on this page.

No. Prototype tooling and repeat-manufacturing tooling serve different purposes; the tooling path is chosen based on how the part will actually be used and repeated, not a single default approach.

Our propeller mold inventory alone spans more than 30 diameter-and-pitch combinations, built through repeat production rather than one-off tooling.

Static thrust testing, three-point and two-point bend testing, fatigue testing, and tensile and compression testing. We do not claim ultrasonic scanning, CMM, or third-party accredited test capability unless a specific project brings that requirement in through a qualified partner.

Not as a fixed number — capacity depends on the part, tooling, and method involved. This is scoped per project rather than published as a general figure.

Process control, tooling logic, and inspection planning are formalized — tolerances, work instructions, and revision control are locked in rather than handled ad hoc, as they can be at prototype stage.

One example is an in-house R&D benchmark, not a customer project: Tulkas modeled the geometry of a commercially available APC 13x8 propeller as an internal reference point and developed a carbon fiber 13x8 propeller with a more efficient blade profile. In in-house static thrust test conditions, the redesigned propeller showed an approximate 6% efficiency gain over the reference geometry. This was a comparative in-house engineering study, not a supply or collaboration relationship with the reference brand, and the figure is specific to that one benchmark rather than a general performance claim.

In anonymized form: for a fan-manufacturing customer, Tulkas developed a composite fan blade production process and has since remained that customer's production partner for the part. The customer name and part-specific figures are withheld; the pattern shown is a prototype-to-serial-production process handed off as a controlled, repeatable manufacturing method rather than a one-off delivery.

Customer and project names are only published with explicit written approval or from a verifiable public source. Where that approval doesn't exist, we describe the engineering pattern instead of the client.

Function, loads, and operating environment are defined first; geometry, material, and process are locked only after that, not before.

No. A defined function and load case is enough to start; geometry can be developed from zero or refined from an existing concept.

Tulkas primarily focuses on platform-specific design and manufacturing. Production or improvement based on an existing geometry can also be evaluated case by case.

Depending on scope, static and dynamic validation, balancing, measurement, and test planning are defined together with the customer requirements.

Depending on scope, we can support part-level design, adaptation to an existing body, or production based on the customer’s main platform design.

No. Parts that require fast field repair, or that are exposed to very high impact or heat conditions, can be better served by metal alternatives. The material decision is made together with the platform requirement.

Technical data is handled through controlled access and limited sharing; program-specific confidentiality requirements are agreed before any sensitive detail is exchanged.

Yes, case by case. The part is reviewed for load paths, interfaces, and manufacturability before a composite alternative is proposed — not converted as a like-for-like copy.

No. Under very high thermal loads, or where emergency field repair is required, a metal canister design can still be preferred. The right choice is determined together, based on operating conditions.

Yes. Cylindrical, conical, and custom-section forms are evaluated based on the structural and interface requirements of the specific canister.

Yes. Prototype canisters can be produced to validate geometry and fit before a repeat-manufacturing tooling investment is made.

No. Where field repair by welding is needed, or on very simple, low-budget parts, stainless steel or aluminum can still be the better fit; the right material is decided together based on the operating conditions.

No. Tulkas designs and manufactures composite foil, strut, and structural components. Hydrofoil system architecture, hydrodynamic analysis, active control, and full boat design are handled by Navarc, Tulkas's group company, at navarc.com.tr.

Surface quality is treated as a production-controlled outcome, not a finishing afterthought, since even small deviations on water-facing surfaces measurably affect drag and performance.