Heljan Class 52: Underframe Detail

Complete Underframe Details

The underframe details are supported on four Detail Planks (parts C1), each plank being unique, as shown above. To identify the 'A' and 'B' ends of the chassis, look at the underslung 'gondola' between the bogies: there is a rectangular opening on the off-side at the 'B' end.

*1: It might be useful to drill the hole shown in this fold-down (sorry it was omitted from the etch artwork) to provide a more secure fixing for a speedometer cable detail (not supplied in the kit). Easiest done before folding up.

C4 and C5 are 3D printed parts to represent the body support pillars. There are two alternative sets, one is 'dished' at the sides (as shown in the drawing) to allow the bogies to swing for curve radii down to about 3 feet. Remove any remnants of sprue from the sides of the lower ends; the lower ends are housed within the spring beams of the bogie subframes and, depending on how accurately the bogies are centred relative to the detail, might need further thinning down to avoid contact with the spring beams.

Exploded diagram

C3 Jacking Points. Fold up and fit into slots in Detail Planks C1. File the front edges to match the appearance of the prototype. Cut down the vertical upstands flush with the top of the Detail Plank.

C2 Filler supports. Make the 30° fold, then fold down the front and vertical upstand, finally folding in the sides. Note that there are wide and narrow variants. Fix to the Detail Plank and cut down the vertical upstands flush with the top of the plank. You can make representations of the fillers and drains from wire and micro-tubing (not supplied in the kit).

C6/C7 Steps. C7 have a chamfer at the back to accommodate bogie swing on curves down to 3 foot radius. Suggest pin in place with two longer wires, which you can cut and trim after soldering to represent bolts as shown.

The Detail Planks are glued to the underside of the chassis block, aligned with the outer edges of the block. The holes in the planks should align with the pivot centres - it's perhaps a good idea to postpone final fixing until you have done the Bogie Detail Second Fix, so that you can check that they're aligned with the bogies in place.

Once you have confirmed the positions of the planks, you can use them as templates to mark and drill holes for the wires representing the air lines and 2mm holes to accommodate the spigots of the 3D Printed support pillars.