Since this is a blog build, and not a magazine one, I can use any bit of fancy-pants kit at my disposal, without worrying how anyone else will be able to do the same. Hence, out comes my Hobby Holidays chassis jig.
It needed a little freeing up, but nothing that some WD40 and remembering to slacken ALL the Allen bolts wouldn't cure.
The rods were carefully set to match the spacing of the conrods, reminding me that I never got around to ordering the set with smaller ends that actually fit into the crank pin holes. Still, I think I'm accurate enough.
Once the chassis sides and spacers were soldered up, I put it on the jig with the bearings. Or at least I did once I'd opened out the centre holes and huge along (at least 1mm) as they seemed to be in the wrong place. The ends are fine, and using the jig, this isn't a problem - just slosh plenty of solder around and let it sort itself out. The gas torch was handy here as there's a lot of heat absorbing metal.
Once cool, I cleaned it up and then remembered I've run out of Shiny Sinks cleaner and need to find a replacement before the flux stars going green.
I think there are at least two kinds of etched loco chassis. There is the type that has been designed with etched tabs and slots (or half-etched slots), and can be assembled (with care) on the workbench with basic tools and skills, with the expectation of a square and free-running chassis. Then there is the type where the designer thinks they are doing you a favour by not providing any positive locating devices at all! These are really “scratch aids”, and they need some sort of assembly jig — as well as a higher degree of skill — to achieve an acceptable result.
ReplyDeleteThe 1 millimetre discrepancy on the middle bearing is a bit of a worry, and would probably have stumped me! A good thing you had the frame assembly jig then…
Oooo, goody; I've missed your Blog Builds.
ReplyDeleteNow about that 3mm scale class 24...