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Kayak rudder cable retractor, reverse engineered

A new rudder cable retractor for a private client's kayak, rebuilt in CAD from the worn original as a stiffer, serviceable housing in carbon-fibre PETG, then fitted and tested by the client.

Client
A private client
What it is
The housing that guides a kayak's rudder lines
Started from
The client's worn original retractor
What we did
Reverse engineering, CAD redesign, prototype and the final sets
Start a prototype (opens WhatsApp) Send a brief
Sets of retractors in the order
2
Grade of the stainless steel hardware
316
Days from the brief to the CAD redesign
3

What we brought

  1. What we can do

    Rebuilt from the worn original

    We took the client's original retractor apart, measured its housing and pulleys and rebuilt them in CAD, with the mounting flange matched to the client's template.

  2. How we look after you

    Made to be serviced

    The housing is held together with marine-grade stainless steel bolts and nuts, never screws into plastic, so it can be opened and closed again and again.

  3. What you get

    Fitted and tested

    The client fitted the prototype to the kayak and tested it before we made the final retractors.

The build

How we built it

5 steps, from the brief to the finished piece. Pick a step to jump to it.

The brief

Step 1 of 5 · 10/02/2026

Part
Kayak rudder cable retractor, housing and pulleys
Started from
The client's original retractor and a template for the mounting holes
Material
Carbon-fibre PETG for stiffness and UV resistance
Hardware
316 marine-grade stainless steel bolts and nuts
Our scope
CAD redesign, a prototype, 3D printing and assembly of two sets

At Additive Inn, our 3D printing studio in Singapore, we reverse engineer parts that can no longer be bought. A private client's kayak had a worn rudder cable retractor, the housing that guides the rudder lines. We were to rebuild it as a reinforced housing that can be taken apart and serviced, with its pulleys and a mounting flange made to the client's template, and make two sets.

The original retractor we started from.
Taken apart, with its pulleys and pins.
The original, from the end.

Design and prototyping

Step 2 of 5 · 13/02/2026

We rebuilt the retractor in CAD as a two-part housing on a wide mounting flange, with the flange holes matched to the client's template. The two rudder lines run through the housing over a pair of pulleys, each turning on a pin, and the halves are bolted together through the housing.

The first design went to the client as a deck on 13 February. The client came to our studio the same afternoon with the rudder line, so we could check how it runs inside the housing, and we updated the design that day.

  1. Revision 0

    The first redesign, a two-part housing with two printed pulleys, bolted with M3 stainless steel hardware, 52 x 91 mm on its flange.

    Render

  2. Revision 1

    Reworked the same day, after the client showed us how the rudder line runs inside the original.

    Render +1 more

Printing the prototype

Step 3 of 5 · 16/02/2026

We printed a prototype in carbon-fibre PETG on our FDM printers, the housing, lid, flange and pulleys, and assembled it to check the line ran through it. It was packed for the client on 19 February.

Packed for the client to collect.

Build and assembly

Step 4 of 5

Every joint in the housing is a bolt through to a nut, in 316 marine-grade stainless steel, so the plastic never carries a screw thread and the housing can be opened for servicing.

The assembled prototype, bolted together.

The final build

Step 5 of 5 · 26/05/2026

The client fitted the prototype on the kayak and tested it. Once it had proved itself, we made the final retractors with stainless steel hardware, ready for collection on 26 May.

On the kayak, with the rudder.

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