The inner frames are etched in one piece and form the working heart of the loco, holding the axles and gearbox in place. They can be built rigid or compensated. Compensating this loco is so easy that there's little point in building it rigid.

The instructions suggest fitting the lead axle bearings in place before folding up, I chose to fit the bearings after folding to make holding the frame sides secure for bending easier;

Not everything goes as planned... Note the section above the black line. This has tried to stay flat with the frame sides despite being clamped securely down with a Hold + Fold. Some remedial work with pliers sorted the problem out on the first frame. On the second frame I had the same problem on one side so before folding the second side I deepened the fold line as much as I dared with first a triangular needle file then a square file to get a good 90 degree fold. This worked well so I flattened out the first side, did the same and tried bending it up again, with predictable (in hindsight) results;

Note the split in the nearest end between the black lines and the break in the etch at the other end (difficult to see but again between black marks). Ho hum.

It would have been better to either deepen the fold lines in the first place or to have held the frames in something more solid than a Hold + Fold - either steel bending bars held in a vice, or directly in a vice if it has good jaws (this is how Mike Edge does it, he obviously has a better quality vice than me). I'm hoping that Mike can sell me another etch.

I should point out that this problem is entirely of my own making and nothing to do with the design of the kit. Although I do feel that top of the leading end of the etch could do with strengthening, perhaps by radiusing the corners of the gearbox cut-out.

As mentioned the bearings were fitted after the frames were bent up. They needed to be filed down to clear the gearbox, I did this before soldering in place. To hold the bearings for filing I slipped each bearing over a length of 2mm axle material in a vice (my vice has horizontal and vertical grooves for holding round stock);

Swing arms can either be fitted inside or outside the frames depending on whether your working to OO or to EM/P4. As these two are being built to EM swing arms are fitted outside;

Peco track pins are used as pivot pins (a tip picked up from Kenton's Judith Edge NBL shunter build) and I blackened the swing arms to avoid soldering them up solid when soldering the pins in place.

Underneath a pivot is needed for the axle to rock on;

The .45mm wires are for the brake shoes.

A couple of pics. of the inner frames with the gearbox in place;

I had to file some material from the frame top to clear the gearbox, especially around the pivot pin which holds the swing arm in place. It might have been better to have dispensed with the seperate pivot pin on the gearbox and soldered the pivot axle directly to the swing arm, this is covered in the gearbox instructions.

There is still work to do to this assembly but I'll leave it for now whilst I start on the footplate.

Paul.