One e-bike wiring box. Three orders of refinement.

An e-bike controller connects the battery, lights, brakes and display. We refined a customer-supplied box for those wiring connections, proved the fit on the first prototype and carried the design through new controller sizes and repeat production.

Black, light blue, dark blue, purple and red e-bike wiring-box parts laid out together — Wiring-box components produced across the project’s colour variations.

White prototype e-bike wiring box, lid and front mounting piece

First, make the fit right.

The box holds the wiring connections on one side of the e-bike controller. A matching front piece attaches to the other side, and the assembly mounts to the bike frame. Starting with the customer’s files, we adjusted the fit between parts and moved a lid screw hole inward to leave more material around the fastening. We chose PETG for a durable, cost-effective part that prints consistently.

The customer tried the first prototype in their production assembly. It fitted as intended on the first attempt, so the design was approved for production.

Purple e-bike wiring-box parts from the first production order

From prototype to first batch.

With the fit proven, we printed the first order in black, light blue, dark blue, purple and red. The colour changed, but the body, lid and mounting pieces still had to assemble the same way every time.

Three prototype boxes fitted to controllers

One design, three more controllers.

The next order called for the same style of box in three new controller sizes. We adapted the box, lid and front mounting piece for each one, changing the dimensions and mounting-hole positions while keeping the design consistent.

The customer checked the first prototypes against the real controllers. All three fitted, so the new variants went straight into production.

Rows of black e-bike wiring-box components from the second order

Made in batches, checked as sets.

Each set was assembled to check the fit, cleaned and visually inspected. We checked the screw holes with the intended fixings and put selected prints through hands-on pull and squeeze checks to see how they behaved.

Close-up of a black printed lid with a carbon-fibre-look texture

A better finish on every lid.

For the next repeat order, we printed each lid against a textured build plate. The pattern transferred to the lid, giving it a carbon-fibre-look surface without changing the material. We introduced the finish ourselves, and the customer loved it.

Black e-bike wiring box with carbon-fibre-look texture on its side

Then carry it around the box.

We also designed a subtle carbon-fibre-look raised pattern into the outer walls of some boxes. Unlike the lid finish, this texture is part of the box geometry. The finish was a hit, and we moved the textured boxes into production to meet demand alongside the standard version. The project continues with further orders.

The outcome

From a supplied design to repeat production.

We took responsibility for the details between the customer’s file and the finished part: fit, new variants, batch checks and the final finish.

First prototype: fitted the customer’s production assembly.
Three more sizes: checked on real controllers before production.
Repeat batches: assembled and inspected as sets, with a custom finish.

Side view of a black electric mountain bike with purple wheels and accents — **The bike behind the project**An e-bike from the customer, showing the machine these wiring boxes are made for.

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