Wheel repair · CNC diamond cutting
Repairing diamond-cut wheels. Exactly as they were made.
A damaged diamond-cut surface can be neither painted nor polished. It has to be re-cut. Our CNC lathes capture the wheel contour beforehand and machine the face to an accuracy of 1 µ.
- 1 µmachining accuracy (1/1000 mm)
- €250per wheel incl. VAT, incl. 3D scan and acrylic coating
- up to 28"wheel diameter on our CNC lathes
The process
What diamond-cut means
After the colour coat, the face of the wheel is turned on a CNC lathe with a diamond tool. The result is a bright, metallic surface with very fine turning marks, which is then sealed with transparent clear powder, matt or gloss. The contrast between colour and bare aluminium is often called "bicolour" or "diamond cut". The share of diamond-cut wheels in original equipment has risen significantly in recent years.
As attractive as these surfaces are, their repair is just as demanding. Scratches, kerb damage and oxidation cannot be fixed by painting or mirror polishing. The only proper repair is a fresh CNC diamond cut, exactly as in manufacture.
Why our CNC process is different
We developed our CNC lathes ourselves because there was no suitable solution for repairing diamond-cut wheels.
Contour capture to 1 µ
The wheel manufacturers' CAD data is generally not accessible. Our integrated touch probe captures the wheel contour beforehand and allows true-to-form machining to 1/1000 mm. The finish matches the original exactly.
Non-uniform re-cutting
A process developed by Mainhattan-Wheels: more material is removed only in the damage zone, usually at the outer rim edge. The rest of the face is skimmed by only hundredths of a millimetre. The result is a homogeneous surface with minimal material removal and a much lower safety risk than conventional re-cutting of the entire face.
Wet machining
We cut with specially developed emulsions from our own wheel production. This raises the gloss level and carries chips away from the cutting edge, so fewer defects occur. The emulsion is washed off without residue after machining and does not affect the coating.
Sealing with acrylic powder
After cutting, the wheel is coated with transparent acrylic powder, exactly as in the manufacture of premium wheels. This protects better than wet clear coat, nano or ceramic seals and offers maximum weather resistance.
Results
Before and after
All examples come from our workshop in Dietzenbach.
Worked example: CNC diamond cutting of a powder coated wheel
The four steps, shown on a UROS wheel from our own production.
Documentation and questions
Documentation and safety
Your safety always comes first for us. All wheels are marked before processing. Material removal, CNC program, 3D measurement reports and the materials and colour codes used are documented, so that every wheel is 100% traceable. The minimal material removal of non-uniform re-cutting preserves the strength of the wheel.
Whether a wheel may still be cut is decided by the inspection on site: with structural damage, cracks or material removal of more than 0.5 mm we recommend replacement.
Example video
CNC machining of an Audi Rotor wheel and our CNC lathes in use.
Our complete solution for repairing diamond-cut wheels with a touch probe for contour capture.
Questions about CNC diamond cutting
What is the difference between diamond cutting and polishing?
In polishing, the surface is smoothed with chemicals and abrasives. In diamond cutting, it is machined away with a diamond tool on the CNC lathe. Polished wheels can likewise only be properly repaired by CNC cutting.
Why can a diamond-cut wheel not simply be painted?
Because the look comes from bare aluminium with fine turning marks. Paint or polish cannot recreate this structure. Only a fresh CNC cut returns bicolour wheels to their original condition.
How accurate is the machine?
Contour capture and machining are carried out to 1 µ, i.e. 1/1000 mm. With non-uniform re-cutting, the undamaged part of the wheel is skimmed by only hundredths of a millimetre.
What does CNC diamond cutting cost?
€250 per wheel including 19% VAT. This includes a 3D scan and run-out check, the scan of the wheel contour and the subsequent acrylic coating. If painted or powder coated areas are also damaged, the costs for powder or paint are added. We prepare binding quotes after inspecting the wheels.
Can every damaged diamond-cut wheel be repaired?
Provided the structural integrity is intact, yes. Scratches, kerb damage and oxidation are typical cases. Cracks and severe deformation are not repaired.
How long does it take?
Usually 1 to 2 working days, slightly longer with an additional colour coat.
Would you like your diamond-cut wheels repaired?
Send us photos. We will check whether CNC diamond cutting is possible and quote you the price.