Coombe Barton

I'm not suprised you found attaching the buffer beam difficult if you just tin the mating surfaces and try to sweat them together. For perpendicular joints like these it is much easier, and gives a stronger joint, to just run a fillet of solder along the inside of the joint. Don't worry about visible solder in places where it is not going to be seen. When cleaned up it takes paint well.

 

What I do is to cradle the running plate upside down in my hand and hold the buffer beam against the plate and valances with a small piece of wood with my first finger. Then drop a small piece of 145 degree solder or carry it on the iron (according to preference), add plenty of flux and run the iron along the joint. I also put a small bead between the beam and the valances. If you find your iron is not producing enough head to make a smooth bead, your tip is probably too small. I use an Antex 25W iron with a 3mm chisel bit and find it quite sufficient for the main parts of any 4mm build.

 

I'd also recommend cleaning up the lamp irons before fitting. It is very difficult to get a file to them without scratching anything else. The ones you have that pass through the running plate are fairly strong, but those that are fixed on top, especially those with a half-etch fold, will almost certainly break if try to do anything to them.

 

Nick

The steps also have a half etched line in them. I would recommend reinforcing them at the rear before fixing them to the footplate - they are very vulnerable to handling damage otherwise!

 

Martin

I have reinforced the rear of buffer beams on some of my locos with right angle brass section.  Slots / holes need to be cut into them to clear the buffers and rear shaft of the couplings. Possible interference with the ends of the chassis needs to be considered as well. Possibly a 7mm scale thing, as stock is heavier and 1kg of loco hitting a dead end is quite brutal.  Have done the same with steps to strengthen half etch joints, as steps are vulnerable to handling damage.  I do adopt a belt and braces approach with my models, including buildings.

 

Is the Modelex 45xx the same etchings as the kits sold under Malcolm Mitchell's  own name?

...Possibly a 7mm scale thing...

Yes, I really doubt the need in 4mm unless there's no support from valances.

 

I definitely agree about steps, though, as they are often delicate in 4mm.

 

I also wonder about whether there's any difference between versions of the Mitchell kit. The etches shown in the first entry do appear to be quite simple compared with, say, the Mitchell 517 although the latter copes with more variation (cabs, bunkers, firebox, smokebox, etc.).

 

Nick

....Is the Modelex 45xx the same etchings as the kits sold under Malcolm Mitchell's  own name?

 

Not quite. As far as I understood it, the Malcolm Mitchell 45xx via David Geen was a slightly updated design, and there was also a 4575 variant (sloping tanks) made available.

Buffalo - I thought I had cleaned the lamp irons up but have finished the job post installation with a grinding wheel in a Dremel. Light touch and it worked. Made sure it only touched the lamp iron with a little inventiveness with a vice or two and a flexible drive.

 

Martin - good idea - thanks - will reinforce with angle before I go much further.

 

PD&SWJR  - I'll take your advice and put in some brass angle.

 

And there is a difference - as Horestan says they're a different generation. the 44xx Mitchell kit I have from David Geen is a different beastie. although the instruction copying still leaves a bit to be desired. It's certainly not the booklet that Guy Williams described in MRJ 32.

Slightly O/T, is the 44xx kit from David Geen a 'reduced' version of the Mitchell 7mm that I built about 15 years ago?  I probably still have the instructions somewhere and that was definitely a booklet.

Don't know. The booklet that was provided back in the 80s contains the same information as the various copied pages in the kit it is't a booklet any more. Guy Williams praised the substantial box, and that's still there, as are the etching wrapped in tissue paper.

 

It certainly seems a better put together offering than the Churchward, having a nickel silver chassis rather than brass. I suppose I'll find out when I build it.

 

However I have discovered that the Churchward instructions are inkjet printed rather than photocopied - a drip of water proved that.