1:35 Alvis FV622 Stalwart - Cab Roof Correction (3D-Printed / for Airfix Kits)

The roof the whole impression of the cab rests on

The cab of the Stalwart has an unusual shape. It sits high above the front pair of wheels, narrows toward the front, and its roof passes into the sides in a soft but precisely defined radius. It is exactly such a transition that gives an injection mold trouble: the parting line runs across it and the resulting edge tends to be either too sharp or, on the contrary, smeared. A modeler's eye reacts to that reliably, even if it often does not register why.

What the correction part is for

The replacement roof is fitted in place of the original and returns the correct profile to the cab. The difference shows above all when seen from the front and from a three-quarter view, that is from the angle at which the vehicle is most often photographed. The printed surface also holds sharper transitions around the edges and openings, without any need for filling.

Replacement procedure

Separate the original roof with a saw guided along the joint, not across the material, so that you do not needlessly take material away where the new part will seat. Do the dry fit several times and fill any slack with a thin strip of plastic, not with filler, which sinks during sanding. Glue with super glue in small sections and keep checking whether the cab is symmetrical. Apply the paint only after leveling the whole upper surface with fine abrasive paper.

The vehicle itself is not in the package; this is a replacement part for a kit already obtained.

Keep checking the symmetry by eye from the front against the light, not just by measuring. The eye will reveal a deviation between the two sides sooner than a ruler will, and once a surface has settled askew it is practically impossible to correct. Back the abrasive paper with a hard plate, then, so that a true plane is produced and not waves.