Required changes building in Scale7
Overall the kit was quite simple to convert to Scale7, there were a few minor changes required but nothing significant. This is list of the items that will need to be tweaked specifically for Scale7, if you’re using one of the 7mm narrow gauges ( 0F, 31.2, 31.5 et al ) these modifications are probably unnecessary.
1. The loco frames are separate items with four etched frame spacers including location tabs, a couple of the spacers have an etched fold line to create a right angle which helps to ensure that the frames are held square. I made replacement frame spacers from nickel-silver sheet (16thou) by cutting a long strip 28.5 mm wide, this was then cut into the four lengths using the supplied etchings as a guide for length. I didn’t bother with cutting the tabs into the spacers as I prefer to align the chassis on the axle hornblocks – see the main chassis build for details.
2. The sandbox castings need thinning down. With the wider frames and thinner driving wheels the sandbox castings are too thick. As supplied they will just start to catch on the rear of the coupling rods and need about 1/16″ taking off the thickness. This can be trimmed with a large flat file or if you have the machinery a lathe. For these I used my mini lathe, mounting the casting in an independant four jaw chuck and lightly skimmed 80thou or a couple of mm from the casting.
Very little needs to be done to the bodywork, it can be built more or less as standard. The only modifications required for Scale7 appear to be,
1. A slight trimming of the footplate just behind the leading drivers is required. With the wider chassis frames the footplate between the leading driver splasher and the front of the water tank overhangs the frames a little and so can be trimmed back to line up with the wider frames.
2. The inner faces of the water tank (parts 19 and 20) need trimming to clearing the middle drivers. With the wider back to back for the Scale7 wheels these will catch on the inner water tank etching as supplied. It’s much easier to trim prior to fitting rather than attacking it with a slitting saw when it starts shorting out.