Roxey Mouldings ICI hopper part 3 - frames 1.

The first job is to cut out the frame top plate and fold down the bufferbeams and stiffening ribs, running a filet of solder along the inside of the bends for strength. The inner-most rib sits directly above the inner-most wheelset, to provide clearence for the flanges I filed 1mm from the bottom of the ribs, leaving the centre section at full depth. To make sure that the filed section lines up with the cut-outs in the bottom plate this needs to be done at the same time as the bottom plate is modified, described further down. In the photo below the right hand side of the inner rib has been filed down;

The bottom plate also has bufferbeams etched onto it. These need removing. My method is to hold the etch in a Hold & Fold (a 5.5" one in this case) and gently cut along the fold line with a piercing saw, the frame is easily distorted!

In the photo below the nearest plate has had its bufferbeams cut off. I've drilled 8 extra holes in the etch, the inner 4 holes are drilled 4mm dia. and will be used when I attach the hopper body in place. When the frames are assembled a closed box is created above the bogie stretcher, the outer 4 holes (2.5mm dia.), which are located either side of the bogie pivots, will be used to fill this box with liquid lead.

To give extra swing for the bogies the cut-outs have been enlarged inwards by 1mm, a simple filing job. The black marks show where material has been removed;

The attention now turns to the solebars. There's two rivets to punch out in the centre of the fishbelly section (ignore the others, they'll be covered by overlays) then a half etched overlay can be soldered along the length (RSU (resistance soldering unit) set at 4.5v, Carrs 179 degree solder cream). Soldering is done whilst the main plate is still on the etch. Returning to top plate there's another pair of stiffening ribs to add, these have the ends bent over to 90 degrees before soldering in place. Then the solebars can be added;

 

Once they're soldered up the dragboxes and angle girders can be soldered in place, under the framework at the ends. The dragboxes are simple U shapes and the angle girders sit behind and to either side of the dragbox;

 

The angle girders needed modifying for wheel clearence, a simple filing job. On the left in the photo above can be seen two girders before bending, the upper one is unmodified, the lower has an angle filed into it.
On my kit a section of etch was missing, the section containing the dragboxes, angle girders and strengthening ribs. All easy to re-make (I couldn't be bothered to contact Roxey) but it did of course take time.
Once the dragbox and angle girders are in place thought can now turn to the bottom plate. A pair of 10BA screws are cut down to 7mm long and soldered in place for the bogie mountings.
The bottom edge of the solebar is a thin strip of brass which sits outside of the fishbelly frame. Being thin it conducts heat easily, put an iron near it and it will readily expand and buckle, the inner part of the frame staying the same length. The solution is to cut the thinner part with a piercing saw, hiding the cut behind the brake wheels. This allows the solebar edge to expand when heated without buckling, think rails in hot weather;

Another modification is to cut back the etched bottoms of the angle girders, to allow the wheels to swing, modified etch on the left;

Now the bottom plate can be soldered in place on the frames using 145 degree solder. Here's the two chassis prior to cleaning up;

There's a few more parts to be added to the frames, then I can turn my attention to the hopper body.

All soldering done with my 25w Antex and 188 degree solder except where stated.

Paul.