Heljan 47/Kestrel/Lion/Falcon: Final Assembly

Fit the bolsters to the pivot frames and check the length of the 2mm pivot screws. Trim the screws if necessary such that they don't protrude more than 0.5mm or so from the captive nut in the bolster top. Remove the bolsters from the chassis block once more.

Lubricate the teeth of all gears in the drive train using a suitable grease. Lubricate the worm shaft bearings with a light oil.

Fit the wheelsets to the drive unit, ensuring that they are fitted in the correct locations and the correct way round, as indicated by the id marks on the bearing carriers. While doing this, adjust any pickups to give a light preload onto the wheel flanges.

Inserting springs Using a pair of tweezers to handle the springs, and a small screwdriver to manipulate the bearing carriers, thread one of the primary springs through the hole in the ear of the central bearing carrier facing the outer axle (for Falcon this is one from the shorter of the two sets of primary springs).

Thread the spring through the slots in the ears of the bearing carrier of the outer axle.

Thread a second spring through the hole in the other ear of the central bearing carrier.

Thread that spring through the slots in the ears of the bearing carrier of the inner axle.

Springs in drive unit Similarly fit the two springs on the other side of the bogie.

Subframe on wheeling block Take the subframe which goes with the drive unit and place it on the narrow block for wheeling.

Drive unit introduced to bogie Slot the drive unit into the subframe with the primary springs resting on the tops of their spring seats. Ensure that the bearing carriers are correctly engaged in the slots in the subframe, and that the drive unit is facing the right way (worm end towards the coupling end of the bogie).

Fitting primary springs Use a screwdriver to spring the springs outwards and downwards on to the outer faces of their seats.

Primary springs fitted Push the springs downwards so that they slide over the seats, until they clip into place under the seats.

Now take the bolster for that subframe, make sure it is facing the right way, and slide it into place in the subframe, until the lower edges of the four secondary spring seats are resting on the secondary spring wires.

Pushing down gently on the bolster, use a small screwdriver to bend each spring slightly inwards so that it slides up the inner face of its spring seat and snaps into the slot in the seat.

Unclip the circuit board from its rubber retaining lugs in the centre of the loco. This will make it easier to see the fit of the cardan shafts into the sockets at the ends of the motor shaft.

Find the cardan shaft and clip the correct end into the drive socket of the bogie.

Offer up the bogie into the aperture at its end of the loco. Route the pickup wires around the pivot frame. Engage the free end of the cardan shaft into the loco's flywheel drive socket and line up the bogie top pivot with its pivot hole. Fit the bogie retaining screw, sleeve and washer.

Repeat all of the above for the other bogie.

Connect the pickup wires to the correct terminals of the circuit board.

Place the locomotive on some track and give it a test run under power.

Run the locomotive in gently at first. If the loco does not run freely or begins to bind up at any point, pay particular attention to lubrication of the axle bearings. You can feel for any binding by rotating the wheel rims with the fingers - there is enough slack in the drive train gears that you should be able to distinguish between a binding and a free wheelset.

When you are satisfied that the loco is running OK, and that this is the final assembly, remove the pivot screws and apply a thread locking compound to the threads of the captive nut in the top of the bolster (you can use a proprietary compound, but cyano glue, paint or even nail varnish will do the job). Replace the pivot screws, tightening them only so far as to put a slight preload between the bolster top and the pivot plate, whilst retaining a reasonably free (it doesn't have to be loose) pivoting movement. Give the loco another test run through some pointwork to make sure it's free enough.

Finally, replace the body of the locomotive.

All being well, thats it! - the modifications are complete and you have a(nother) sprung diesel loco.

IMPORTANT NOTE: If you need to remove the body subsequently, please DO NOT at any stage attempt to pull the chassis from the loco by pulling on the bogies, as this may damage the spring mountings.