Tuesday, 13 November 2018

November 2018 Meeting

This month we held part 1 of our planned locomotive workshop on converting a Dapol Terrier to 2mm finescale (that is the chassis).

Before we got under way there was time to admire Keith's point work for a fiddle yard. This is constructed with flat bottom track soldered directly onto a PCB board, with the necessary electrical isolation cuts. This method would suit embedded track for an industrial or dockside setting.

Dapol Terrier conversion, Part 1

The replacement chassis etch and items from the parts list were obtained from the 2mmAssociation shop 3, with a few added components suggested by Keith and Alan. A couple of useful supporting documents can be found on the 2mm Association website; Etched replacement chassis for RTR loco bodies, includes parts list and generic illustrated instructions for several locos (including the Terrier). A specific etch diagram and chassis arrangement for the Terrier is here. Both documents are downloadable PDFs.

The Terrier etch and diagram, chassis arrangement and the sacrificial Dapol Terrier

Starting off; Keith was careful to explain the point at which we should begin is the accurate positioning of the axles. At this point we ignored the frame assembly jig as it is possible for this to become distorted, instead using the coupling rods for accuracy.

The etch and a block of 'synthetic resin bonded paper'

First Keith tinned the fold-over coupling rods without removing them from the etch.

(left) Using the block of 'synthetic resin bonded paper' he marked out a line and positioned one end of the coupling rods on the etch onto the line and using a .5 drill to insert a .5 locating pin all three axle positions.

Satisfied the coupling rods were accurately located onto all three pins, both coupling rods were removed from the etch...

...then folded and the three layers sweated together and tested again on the pins (below)...

...resulting in the the completed coupling rods.

The next stage was to build the Frame Assembly Jig, cut from the etch.

The sides and ends were folded up to form the box, checked for square and the tabs were soldered in position (below)

(this picture shows Keith using his own jig to hold the etched frame assembly jig square whilst soldering the tabs, note the axes are also in position)

This picture shows the 1.5mm axle steels in place which have been drilled to take .5 crank pins enabling the coupling rods to be checked again.

End of part1; many thanks to Keith

In case it helps fill in any gaps, included are sketched notes below.

Loco of the month is the Terrier!