The Rhymney M Class saga, in 3mm

[NCB]

Another tiny bit of progress. I don't like cast handles on smokebox doors, so replaced them on the casting I had lined up:

 

I carved off the originals using a sharp Stanley knife blade, then drilled a 0.4mm diameter hole.  The handles were formed from a bit of 0.4mm nickel silver wire bent a right angles, with another bit soldered across the corner, the lot then trimmed to size and stuck in the hole.

 

Looking at the pic the casting might benefit from a light polish.

[NCB]

Starting to add the castings I have to the body. First up, the buffers and the smokebox front. In GWR days it seems they were fitted with GWR tapered buffers with a small step on top (from the pic in Rhymney Railway Drawings), and I had some 3mm Society castings for these. I usually use strong superglue or araldite to attach castings; in this instance I use ZAP SLO-ZAP.

 

 

Edited October 9, 2017 by NCB

[NCB]

Added the castings for the tank fillers and vents, and the sandbox filler:

 

 

Need to add the front springs, which might be a bit tricky. Also the firebox backhead. After that it's thinking about the castings on top; may have a suitable one for the safety valve cover, otherwise think I'll have to get really stuck into Blender or similar, for 3D prints.

 

Have also reached the point where adding weight and getting it correctly distributed, to fine-tune the running, is needed. Probably the thing I'll do next.

Edited August 18, 2017 by NCB

[NCB]

A long delay ..... I ran out of Araldite, was busy doing other things, eventually dropped into Halfords to get some more, and finally managed to find some space on the workbench to progress things.

 

I'd reached the point where stuffing some weight into the body seemed a good idea, and Araldite was a good glue for this. So, I chopped up some lead sheeting (bought a roll from a builders merchant years ago, I'll only use a fraction) to obtain two strips the right size to fit into the side tanks, and chopped each in two so that they were easier to squeeze in. You can just see some in this pic:

 

 

This improved the balance of the locomotive, but on test I could see more was needed over the rear driver and radial truck, so next stage is to carry out tests with some stuck in the bunker. Once I've the weight sorted I can think about adding the remaining fittings.

 

Main problem at the moment, apart from time, is that my main PC is stuck in a Windows repair loop, so I'm surviving on backup laptops. I'll need to resurrect the PC as that's where all my CAD stuff is. So I've a few more details I can add, but the chimney and dome may be some way off.

[NCB]

Next job: adding the boiler backhead to the cab. Being hardly visible, I wasn't too fussed about the details (which I knew little about anyway) and found amongst the 3mm Society parts list a backhead for a slab-sided Belpaire firebox, of the right size. It's probably from an LMS 2P. Here it is in place:

 

 

Also, have been playing around with getting the balance right. Here's the loco on a bit of test track with some lead weights stuck in the bunker:

 

 

and also on a 29" radius curve which mimics the one I'll need on the station approaches:

 

 

The weight is probably overdoing things. I reckon the balance point on the locomotive needs to be about halfway between the front and rear pivots for the compensating beams, so that all wheels carry roughly the same amount of weight. Without the weight it's too near the second driver; with it it's too near the third driver. So I'll see how it does with about half that weight.

 

The 29" curve is built using the Society's 14.2mm track bases, a boon to knocking up test track. I've been using it to test all my stock. Most is OK, if near the limit; a few items are unhappy. The M goes round pretty well, so the method I've used for the suspension works! I'm in the process of buiding a 29" test curve involving gauge widening, to see if that makes a difference.

Edited September 14, 2017 by NCB

[NCB]

I've completed my 29" radius test curve with gauge widening. Here's a pic with the M standing on it:

 

Sleepers are cut from 1 x 2.5mm Plastruct using that very useful tool, a NWSL Chopper, and placed on the Templot template using double-sided tape. Chairs and code 60 bullhead rail are from the 3mm Society. The outer rail was laid first, with the rail being pre-bent to roughly the right shape, then the inner rail was added using the triangular gauge seen in the pic. Plastic Weld was used to glue chair to sleeper.
 

 

The M sails round it with no trouble, probably even smoother than the 29" test curve seen in the background which was seen in the previous post. The amount of widening is quite small. I'm not sure if the smoother performance is actually due to the gauge widening, or whether laying chairs individually rather than using track bases results in a smoother curve.

 

This time I've a smaller chunk of lead in the bunker, probably about the right amount.

 

The curve in the foreground is 25" radius. It's only purpose was to satisfy my curiousity to see what stock can get around it!

[NCB]

Still not back into the full swing of modelling; waiting from the clocks to go back! But I have managed to get the weight in the bunker sorted out.

 

 

There's 4 layers of lead sheet in there. With that in, the model balances midway between the front and rear compensation pivots, which ensures even loading on all 8 wheels. Under test this appears to be about right. The lead is glued in with araldite.

 

Next job to is get into 3D printing the chimney and dome, so a steep learning curve. Reckon to concentrate on this during November. In the meantime, plan to build the final baseboards for the layout, which I've been putting off for ages :-(

[NCB]

Been a long time!  But I've finally done my first 3D print, the safety valve for my Cambrian Seaham. So I'm moving towards doing the chimney, dome and top feed for the M. I also have some etchings for constructing the front springs. So things are moving ... slowly!