Wednesday 4 July 2007

Onwards and Upwards

Big strides forward over the last couple of days. The chassis is now in the erecting shop and nestles safely in the frame jig. You will notice the different centre spacer; this comes as part of Bob's kits and spaces the frames to suit his etch-designed chassis.

The D49/2 has a separate etch of pieces replacing the main etch which covers the D49/1 variant. Extreme concentration has now been the order of the day; matching etch numbers to instructions and moving backwards and forwards through the main instructions, those for the D49/2 and the exploded diagrams. All of this requires a quiet house - kids at school and missus at work!

I really like how the etches for the cylinders and slidebars are inserted as pairs and then the central piece is removed when the PCB spacers have been added. This is giving the whole chassis a nice rigidity and ensuring that the pieces remain in line and square. I haven't soldered them in yet as there are still valve end plates to be added (one done, three to go!).

The slidebars and cylinder faces are made up by sweating several layers of etch together (in the case of the slidebar, no less than five layers!). Now this would have been easier for the kit-builder as a casting, but I fully appreciate that extra castings would increase the price of the kit, possibly beyond the reach of many. So I am happy to sweat these layers together.

The design kindly incorporates guide holes through which 0.3mm wire may be slotted to align the numerous pieces. I struggled with this at first, then hit on the idea of making a little hair-grip type arrangement with the wire. The pre-tinned etches slot on and are then crimped together with tweezers whilst heat is applied. Once the layers are all square and tight together, the piece can be cleaned up; snip the protruding hairgrip and retain for your next piece (usually good for three or four pieces if made sufficiently long) and then clean up with files and abrasives.

Making these pieces has been, on the whole, most thereputic. Sticking reamers into fingers whilst opening up the holes after tinning was not too much fun, but I am enjoying the rest of it. Holding the small pieces by hand and carefully filing off excess solder and the cusps and remains of tabs, is for me a very restful process. You can feel the file abrading the metal and removing small amounts stroke by stroke; it has an almost magical quality sometimes. And when the finished item slots into the frames and starts to look like a real loco, then you really start to feel you're getting somewhere.

This shows the rear of the cylinder with one valve end plate attached as per the instructions above. You can just see the ends of the 0.3mm wire protruding; not cleaned that up thoroughly have I? The guide holes are evident on the left hand side.


Edward Sissling said...

Good to see the D49 progressing.

Still not aware of any of the 20 other kits sold beng under construction yet! You could crack it by AGM time at this rate and enter it in the Groves.

Got that tank engine painted yet? :-)

Yorkshire Square said...

Funny, you should mention the N8. I have stripped it back to metal and today I received in the post a box of goodies from A little while ago on the VAG, Mark Fielder mentioned Vallejo acrylics, so I thought I'd give these a go. I've got a couple of colours for the airbrush and an aerosol of matt varnish. Also I thought I'd try a different primer; Tamiya Metal Primer in an aerosol. I was a bit perturbed when it came out clear! But it seems to give a nice base, so we'll see how it progresses. Maybe some pics in my next post!