Eric Robb RC Eric Robb EricRobbRC.com · Builds · Tools · Custom Parts
Giant-airplane hardware · made for builders

Heavy-Duty RC
Control Linkage Kit

Laser-Cut Control Horn + Servo Mount System for Large RC Aircraft

A complete heavy-duty linkage solution for large scratch-built RC aircraft, based on the control system developed for our 20-foot RC airplane.

2 Pack two complete linkage sets

$29.99 per kit · $15.00 per linkage set

Choose your pack

Two control surfaces: a big elevator and rudder, or a pair of ailerons.

  • Laser-cut plywood control hardware
  • Designed for large custom RC aircraft
  • Two complete linkage sets per kit

The 4-Pack is $4.99 less than two 2-Packs.

  • Designed and produced for RC builders
  • Developed on a 20-foot airplane
  • Servo not included

Build the linkage. Mount it. Fly it.

Heavy-duty control hardware developed for giant RC aircraft.

Eric standing arms-out beside the unpainted pink foam 20-foot airplane at Flite Fest
Why it exists

Built for Airplanes Bigger Than the Hardware Store Solutions

When you’re building a large RC airplane, the usual lightweight plastic control horn can quickly become the weak link in the system.

This kit gives scratch builders a larger, more substantial control linkage setup using laser-cut plywood components, a threaded linkage, and a dedicated servo mounting base.

It was originally developed while building a 20-foot RC airplane, where the size of the control surfaces demanded something much larger than typical small-aircraft hardware.

Developed on a 20-foot RC airplane

The whole system

One System From Servo to Control Surface

Instead of sourcing each piece independently and figuring out the geometry from scratch, the kit gives builders the core parts needed to create a straightforward heavy-duty control linkage.

The full linkage on the tail of the 20-foot airplane: the dual-plate plywood control horn on its base, the threaded pushrod, and the servo on its plywood mounting plate
  1. 1
    Control hornTwo laser-cut plywood plates on a base plate, screwed to the control surface. Two holes for two throws.
  2. 2
    Threaded linkageA threaded pushrod between the horn and the servo arm, with a swivel end at each end. Length is set on the thread.
  3. 3
    Swivel linkage endThe joint at the horn, bolted through the plates so the pushrod can swing as the surface moves. One at each end of the rod.
  4. 4
    Servo mounting plateA laser-cut plywood base the servo screws to, which you bond or fasten into the airframe.
  5. 5
    Servo arm connectionThe second swivel linkage end, on the servo arm, with the hardware to fix it there. The servo and its arm are yours.
What you get

One Kit, Two Complete Linkage Sets

  • 2Laser-cut plywood control horn assembliesTwo horn plates plus the base plates, as pictured
  • 2Laser-cut plywood servo mounting plates
  • 2Threaded pushrods
  • 4Swivel linkage endsOne for each end of each pushrod
  • ✓The hardware to connect the pushrods to the control horns and servo arms

Not included: servo, servo arm, adhesive, and airframe mounting hardware. The screws that fix the horn base and the servo plate to your airframe depend on what the airframe is made of, so they are yours to choose. Aircraft and adhesives shown in installation photos are not included; the photos show the kit installed.

Showing the 2-Pack. Change pack ↑

The kit laid out on white: two servo mounting plates with their cut-outs, four horn plates, four base plates, and two threaded pushrods
The plywood parts and the two pushrods of a 2-Pack. The swivel linkage ends and the connection hardware are in the kit too.
Close-up of the control horn: two laser-cut plywood plates on a base plate held by four countersunk screws, the rod end bolted through the upper hole
The control horn

A More Substantial Control Horn

The dual-plate control horn design spreads the linkage connection across a larger structure than a small single plastic horn and gives large scratch-built aircraft a sturdy mounting point for the pushrod.

  • Two platesThe rod end is bolted through both, so the joint is held on two sides, not one.
  • A base plateFour screws through the base spread the load across the surface instead of through one hole. Airframe screws are not included; pick them for your structure.
  • Two holesMove the rod end to the lower hole for more throw, the upper for less.
  • Laser-cut plywoodCut from plywood, like the airframe parts on the 20-foot airplane.
The servo on its laser-cut plywood mounting plate, screwed down through four corner holes, with the pushrod leaving the servo arm
The servo mount

A Solid Place to Mount the Servo

Large scratch-built airplanes rarely give you a convenient factory servo pocket. The included mounting plate gives you a simple base that can be bonded or mechanically integrated into your airframe.

Screw the servo to the plate, then fix the plate to the structure, so the servo load goes into a plywood plate rather than into foam. Check the plate against your servo before ordering; exact plate dimensions will be listed below once confirmed.

Where it came from

Born From a 20-Foot RC Airplane

This linkage wasn’t designed as a theoretical product. It started as hardware for a giant 20-foot RC airplane project. Standard control hardware didn’t make much sense at that scale, so a larger plywood control horn and dedicated servo mounting system were built instead.

After using the design on the aircraft, the same concept was turned into a kit so other RC builders could use it on their own large custom airplanes.

Watch the 20-foot airplane build → The build write-up
The yellow and orange 20-foot RC airplane on the bench in the garage
The 20-foot airplane this hardware was built for, painted and on the bench.
Designed for scratch builders

Made for the Builds That Don’t Come With Instructions

Designed with large custom RC aircraft in mind. No size, weight or load rating is quoted, because the right answer depends on your airplane; see the engineering note below.

Installation

Straightforward Installation

  1. Position the control horn

    The linkage pivot should be positioned appropriately relative to the control-surface hinge line.

  2. Mount the control horn securely

    The exact attachment method depends on the airframe construction: screws into a hard point, or bonded, with the structure under it reinforced.

  3. Install the servo mounting plate

    Place the servo so that the linkage runs as straight as reasonably possible through its range of motion.

  4. Connect and adjust the linkage

    Set the threaded linkage length, verify servo travel, and make sure the linkage operates smoothly without binding.

Before flight: always verify linkage geometry, full servo travel, control direction, mechanical clearance, fastener security, and structural integrity.

The full linkage on the tail of the 20-foot airplane: the dual-plate plywood control horn on its base, the threaded pushrod, and the servo on its plywood mounting plate
Technical details

Specifications

Kit quantity2 complete linkage sets (2-Pack) or 4 (4-Pack)
Control hornLaser-cut plywood, two plates on a base plate, two linkage holes
Servo plateLaser-cut plywood
LinkageThreaded pushrod, adjustable on the thread, with a swivel linkage end at each end
Included hardwareWhat connects the pushrods to the control horns and servo arms
Not includedServo, servo arm, adhesive, airframe mounting hardware
ServoNot included; check your servo against the plate
Intended useLarge scratch-built and custom RC aircraft
Developed onEric’s 20-foot RC airplane

Only what has been confirmed is listed. Plywood thickness, plate and horn dimensions, rod diameter and length, thread size, fastener sizes and kit weight will be added here once measured on the production kit; none is quoted until then. Need one now? Ask before you order.

Compatibility

Will It Work on My Airplane?

This is intended as builder hardware rather than a model-specific replacement part. You decide where the servo, horn, and linkage are installed in your airframe.

That makes it useful for custom aircraft, but it also means the builder is responsible for choosing appropriate mounting locations, linkage geometry, adhesives, fasteners, servo torque, and structural reinforcement.

  • Measure your available installation area before ordering. Exact plate and horn dimensions will be shown here once confirmed.
  • The servo is not included. Check the plate against the servo you intend to use.
  • Unsure? Ask first with the airplane and the surface in mind.
Engineering note

Read this before you order

This kit is intended for experienced RC hobby use. Aircraft loads vary dramatically depending on aircraft size, speed, control-surface area, servo torque, linkage geometry, construction method, and flight conditions.

The builder is responsible for determining whether the components and installation are appropriate for the aircraft. Inspect all control hardware before every flight. The kit is not certified, load-rated or fail-safe; no formal testing supports such claims and none is made.

Complete your RC build

Label It. Secure It. Keep the Packs Straight.

The small parts I use on every build, sold here too. Each is added to the cart on its own.

Common questions

Questions before you order

No. The servo and its arm in the photos show how the mounting plate is used and are not included. Bring the servo you have sized for the surface, with its arm.
Two with the 2-Pack, four with the 4-Pack. Each complete set is a control horn assembly, a servo mounting plate, a threaded pushrod and two swivel linkage ends, with the hardware that connects them. Four sets covers elevator, rudder and both ailerons on one airplane.
Large scratch-built RC airplanes and custom aircraft where the builder wants a more substantial linkage than a small plastic control horn: giant foam builds, custom wood airframes, experimental projects with big control surfaces.
Yes, if the hardware is properly mounted and the foam around it is reinforced. The foam or surrounding structure has to carry the loads the linkage passes into it; on the 20-foot airplane the plates sit on reinforced areas of the stabiliser.
Generally yes, provided the mounting method and the structure under the plates are appropriate for the surface and the servo.
Yes. The pushrod is threaded, so the linkage length is set by turning the swivel ends on the thread, and the horn has a second hole for a different throw.
The mounting plate was made for the standard-size servos used on the 20-foot airplane. Check your servo against the plate before ordering; exact plate and hole dimensions will be listed here once confirmed.
It is the same concept and the same parts as fitted to that airplane, cut as a kit. The photos are of the airplane, not a studio mock-up. If the production version ever changes from what they show, this page and the kit contents will say so.

Something else? Ask Eric — the answer gets added here if it would help the next builder.