I know it's a while since I posted. The mojo has been a bit lacking and in certain areas this kit has been a trial so far which has not helped. In fact it nearly became a shelf queen for a while, but I suspect if I'd started something else the enthusiasm would remain in abeyance. However, I've received valuable help and input from David Boorman, Heather, David Genghis, Mickoo and Dikitriki, to name but five, and others have come in and out of the story. I'm sure I'll need Ian@StEnochs' assistance, so willingly offered too, given time! The various works drawings have also been really valuable.
Putting together all I've learned it looks as though this had two stages of design, the genesis being an etched construction to which castings were added somewhat later. It is also quite possible that the cast boiler/firebox/smokebox was a latecomer to the party and the castings were a reaction to that. In some areas the etches were not updated to take account of the chassis castings as a result of which locations are not identified or are possibly of the wrong size. I'll try to point these out on the way. There is no doubt that some of these issues are resolvable with care and consideration but some are guesswork. Having read Heather's thread through she had just reached the stage of head scratching over the bogie assembly, one of the areas which is now close to resolution for me.
So, after due cogitation I've grabbed the bull by the antlers, grasped the nettle, larded my goins and gone in again.
I looked at the castings for the brake cylinder and associated gubbins which is mounted on a rear frame spacer, so this seemed a good way of easing myself back in.
Comprising about ten or a dozen parts it was a fiddle but actually a joy to construct. Confidence flowed back!!
The tender remains in the state as previously reported but I am now in a position to move that forward. While I was resolving that one, with help, I started on the loco footplate as previously reported and then moved on to the frames. I felt that an understanding of the relationship between bogie and frames would be good if sorted earlier rather than later and this is where the first of the theoretical issues became apparent.
The frame spacers were cut from the etch and a dry run was attempted. On the whole it was good but there is something strange about the attachment of the casting for the bogie to the main frames.
It's also apparent that there was, at one time, a top spacer as there's a cut out shown on the drawing of the top of the frame etches which is not present on the etches themselves. The cut out as shown on the drawing looks to be the same size as the one at the bottom so was intended to take a tab from spacer G or K. Edit - I think that notional top spacer was used to join chassis to body. Whether it's needed now is another question entirely. However it won't be beyond the wit of man to instal. a spacer later if it turns out to be required.
There is a cut out in the bottom of the frames which also fits spacer G or K, but the instructions refer to fitting a casting.
I interpret that to be so that the loco body will ride and slide on the bogie. Here's the casting in question.
and it's considerably longer than the cut out. So should the cut out be widened to the front, to the back , a new cut out filed at the centre - or is a cut out not required at all? There's no help in the instructions. The more I consider this the more convinced I become that the cut out is not appropriate for the castings which should probably be centred.
The instructions suggest that the "cast inter frame bogie support" should be bunged in or around the cut out somewhere. Furthermore spacer G has an offset mounting hole, and after some digging and assistance it appears that this was the original bogie support spacer and that the bogie etch, not now used, was pivoted back from the centre. I suspect that the castings have been substituted as the boiler is very heavy and the bogie casting sliding on the bogie support may be the only way to prevent the front of the loco dipping forward. Certainly it will not be possible to provide sufficient weight at the cab end of the loco to compensate the weight of the boiler.
My approach to this has, therefore, been to erect the frames. I can then ensure the bogie is centred on the bogie wheel cut outs. Alternate spacers were squared up and soldered to each side in turn, to equal out any inaccuracies. In fairness these frames are as straight and true as any I've built for any kit in the past.
If the frames have a weakness it's that, at this stage, the front section waves around in the breeze due to the lack of support. This would be much improved by the presence of the bogie support, but as I don't know exactly where it should go I can't fit it yet. There is an etched spacer to go on the front, behind where the buffer beam will be, but there's no positive location for it. I've fitted and removed it once already as the front of the frames were showing some banana tendencies. That's lack of technique on my part and the next visit to the workshop will see that put right.
Next is a dry run of the bogie.
It's notable here that there is a single bogie frame spacer, intended to go at the front of the frames. There is no rear spacer, although the casting could be considered a spacer in its own right. The instructions propose a wire of indeterminate diameter and length at the rear of the bogie, although the length will simply be determined by the final width between the frames..
First problem, and of my making, is that the bearings are for 5/32" axles but the axles on the AGH wheels are 3/16". I'm committed to using the AGH wheels so reamed out the bearings to 4.8mm, giving a small clearance for the axles. This left very little meat in the bearings but just about enough for them to work within the hornguides. The beams are screwed in to place with a captive nut on the inside of the bogie frames. Whether this is intended to allow the beams to rock I'm uncertain but the fit between beam and bearing is so tight that I suspect not. The fit of the large central bogie casting is also a matter of guesswork, although the relief inside the casting, where it attaches to the frames together with the relationship of casting to beam tops suggests that the casting is fitted centrally, as does the drawing in the instructions.
Here is the bogie, dry run again, being held together by the wheels which, at this time, make a very effective and gentle clamp.
My intention is to solder this casting in place. If at a later date it's found to be necessary to move it forward (unlikely) or aft (quite possible) it won't be beyond my ability to unsolder and resolder in the correct location. One imponderable right now is the height at which the front of the loco will ride, having installed the "cast interframe bogie support" so it may be necessary to provide some shim to make the footplate ride higher, or to remove some metal from something to make it ride lower. A secondary issue is that the wheels are very tight with the backs rubbing on the bearings preventing them from rotating freely. This will be easily overcome by reducing the width of the bearings.
So, that's where I am right now. I think I can now see a way forward, although whether that bogie will have enough swing for a 6 ft curve I'm uncertain.
Looking towards the next stage I've released the frame overlays from the etch. These, together with the rest of this sheet, are as oxidised as any I've seen anywhere. This is strange considering that most of the etches are bright and shiny. These will have to be attacked with some physical polish of some sort, possibly a brush in the Dremel.
Brian
