Today I've been playing with some of the other Trackgang castings I received. Todays victim is the 6' passenger bogie from the 56' car. I've brought a set of these to fit under a 50' Z van which I'm in the process of rebuilding from 20 year olsd castings. As an experiment I'm also going to fit brass bearings to see; 1) how hard it is and 2) if there is any improvement that's worth the trouble.
I started by cleaning up the casting and gluing one side frame to the spreader. Once the glue had set I first drilled out the axle holes on all the side frames with a 1mm drill, and then enlarged them with a 1.5mm drill (take care not to drill too far here but you will need to go at least 2mm deep (with 3mm being better).
I check the depth with my thumbnail on the drill when its all the way in, then take the drill out and check just how far in I am. I went right through to China on one axlebox. The brass bearings are from Markits in the UK (3 quid for a packet of 50) and are of the tophat variety, with a main body of 1mm and the rim about 1.5mm (so I did move the drill about a bit to make a hole that was marginally wider). I then pushed the bearings into the holes so that the bearing was about 0.5mm inside the face of the side frame.
Then, without instaling the wheels I glued the second side frame on. After the glue sets this time round I bend the side frames slightly until I can slip the wheels in and then carefully squeeze them closed again. Some adjustment may be necessary to get the wheels parallel and the bogie sitting square. I then put it on some track and pushed. Not quite Kato quality, but better than Peco.
Summary time. The bogies look quite nice ( the springs don't line up that, but that's my only real quibble which isn't doing that bad at all). The combination of the brass axle bearings with the shorter axle wheel sets improves the running qualities out of sight, which makes it a very worthwhile modification to make.