I know the biggest challenge building the class 26 will be the bogie sideframes. I have wondered about buying something in but in the end stuck to my guns and will have a go at making them myself in plasticard.
The first job is to work out what the hell is going on down there. I'll be honest and admit I haven't really paid much attention to these parts - I've seen them of course but don't really know what most of the bits actually do. To this end my plan is to copy the 4mm Class 33 I have noting the changes from the photos of 26's on the workbench and modifying the plans accordingly.
To start, some 1mm thick plasticard has been marked up with the basic shape. At this point the curved bits are squared up as I want to keep things as simple as possible. Note how I've marked the waste in each as from experience it's easy to get confused and hack off the wrong bit.
Next, some of the corners are curved, probably not enough for the purist but then they probably model by whining on forums rather than chopping up plastic so they can shut up. The sideframes are edged with strips of very thin plastic cut by myself as I didn't have any suitable microstrip and couldn't be bothered to go and get some. In the photo I still have to trim the bottom bits back but you get the idea.
Axle boxes are made by punching holes with a leather punch. This gives circles of the right size (the tool allows you to select different sizes) which just have to be trimmed to fit the slot and glued in place with liquid glue.
So far so good. Now I need some springs.