Custom Compressor Fan Covers | Reverse Engineering & FDM Manufacturing
Printer Under The Stairs — Durban, South Africa | July 2026
When the part doesn't exist — you make it.
Some replacement parts simply aren't available. No spares catalogue. No manufacturer support. No compatible aftermarket option.
When that happens, the choice is straightforward: replace the entire unit, or find another way.
This project was the second kind.
The Problem
A customer in Ixopo, KwaZulu-Natal acquired a MAT Air silent compressor missing its fan covers. On this type of machine, the fan covers enclose the motor cooling fans on each pump head. The compressor had arrived incomplete and couldn't be used as intended.
He had one intact cover from the original set. Standard replacements were unavailable. Custom manufacturing was the only option.
He was referred to us by an existing customer.
The MAT Air silent compressor as received — motor cooling fan housings exposed, covers missing. The compressor had arrived incomplete and was not in a usable state.
Starting Point: One Good Sample
With no manufacturer drawings available, the surviving cover became the reference.
Our engineer measured the geometry by hand and modelled a replacement in Fusion 360. We also made one deliberate design decision: the decorative surface lines present on the original exterior were removed, producing a cleaner finish and reducing print complexity. When the customer reviewed the sample print, he noted the change — and confirmed he preferred the result.
At 148 × 152 × 66 mm per part, dimensional accuracy was critical. The customer was based approximately 100km from our Durban facility, which meant there was no practical option to return the compressor for adjustments once the parts had been printed.
Interior view: 3D printed replacement (left) and original fan cover (right). The concentric ventilation grid and octagonal housing geometry were reverse engineered from the physical sample. The simplified exterior — decorative surface lines removed — is visible on the outer rim of the printed part.
Matching the Specification to the Actual Requirement
The initial quote specified red PETG on our Bambu Lab P2S. For motor-adjacent components, heat resistance is a reasonable consideration — PETG handles elevated temperatures better than standard PLA.
The quote came in above the customer's budget.
Rather than holding the specification, our engineer reviewed the brief. The key question: did this application actually require heat-resistant material?
The customer confirmed it didn't.
We switched to red PLA on the Bambu Lab A1 Mini — the right material and platform for the real requirements of this job. The revised quote represented a reduction of approximately 24% from the original, achieved by matching the specification to the application rather than defaulting to the most conservative option.
The functional outcome was identical. The cost was not.
Front view: 3D printed replacement (left) and original fan cover (right). The redesigned exterior retains the full functional geometry while delivering a cleaner, smoother finish. Both parts shown prior to installation.
Sample Approval Before Full Production
Before committing to six parts, we produced a single sample print for customer sign-off on colour, finish, and design.
He approved it without requesting changes.
This step was non-negotiable. With the customer 100km away and no option to return the compressor for test-fitting, the sample approval process was the mechanism that ensured the parts would be correct before the full run was committed to print. It's standard practice for remote customers and custom components where fit and appearance need to be validated in advance.
The remaining five parts were produced to that confirmed specification. No rework. No iterations.
Manufacturing Summary
| Material | Red PLA |
| Printer | Bambu Lab A1 Mini |
| Part dimensions | 148 × 152 × 66 mm |
| Quantity | 6 parts |
| Print time | ~6 hours per part (~36 hours total) |
| CAD | Fusion 360 — reverse engineered from physical sample |
| Fastening | Mechanically fastened to compressor housing |
| Sample approval | First pass — no changes requested |
| Cost outcome | Approximately 24% below original quote |
The Outcome
Six fan covers. Correct fit. Clean finish. Delivered to a customer who installed them himself in Ixopo.
The MAT Air compressor — previously sitting incomplete — could finally be put to work. The customer was genuinely pleased with both the quality and the price.
The MAT Air silent compressor with all six custom 3D printed fan covers fitted and installed. The project completed a machine that had arrived missing key components — manufactured and delivered to a customer in Ixopo, KwaZulu-Natal.
When the Part No Longer Exists
This project involved reverse engineering from a physical sample, material selection based on actual functional requirements, process optimisation to meet a budget constraint, and remote production management with a sample approval gate to eliminate rework risk.
None of that appears in a product description. It's the work that happens before anything is printed — and it's what determines whether the result is right first time.
For engineers, maintenance managers, and procurement professionals dealing with components that no longer appear in any catalogue, that combination of technical process and practical judgement has direct operational value.
If you have a part that doesn't exist anymore, we may be able to make it.
All images: Printer Under The Stairs, July 2026.
