"Voiding the Warranty" - Mol's experiments in 21mm gauge

[Horsetan]

1 hour ago, Mol_PMB said:

I put this list together mainly of photos of 560 on the Fenit branch, ....

https://www.flickr.com/photos/irishrailwayarchive/53467653382
https://www.flickr.com/photos/irishrailwayarchive/53468560926
https://www.flickr.com/photos/irishrailwayarchive/53468878174
https://www.flickr.com/photos/irishrailwayarchive/53468979775
https://www.flickr.com/photos/irishrailwayarchive/53498929093
https://www.flickr.com/photos/irishrailwayarchive/53499079334
https://www.flickr.com/photos/irishrailwayarchive/53509201430
https://www.flickr.com/photos/irishrailwayarchive/53509204144
https://www.flickr.com/photos/irishrailwayarchive/53511776674
https://www.flickr.com/photos/irishrailwayarchive/53527642129
https://www.flickr.com/photos/irishrailwayarchive/54252114857
https://www.flickr.com/photos/irishrailwayarchive/54418652517
https://www.flickr.com/photos/irishrailwayarchive/54419707054
https://www.flickr.com/photos/irishrailwayarchive/54419902095
https://www.flickr.com/photos/irishrailwayarchive/54419902890
https://www.flickr.com/photos/irishrailwayarchive/54419902915......

Great set of links -  unfortunately the Flickr "irish railway archive" ones are all restricted access.

[Mol_PMB]

4 minutes ago, Horsetan said:

Great set of links -  unfortunately the Flickr "irish railway archive" ones are all restricted access.

...and they are many of the best ones. You need to join the IRRS!

[Mol_PMB]

15 hours ago, Galteemore said:

That’s a great close up. For brass workers like me, it’s also a reassuring proof that platework on the real thing could also be shonky. Check out that front splasher on 655, and as for the gap in the boiler cladding….

Here's 663, the cladding doesn't look too bad on this side but it still looks like it's been dented by some fat fingers and clumsy handling:

But these IRRS photos of the other side show that a whole cladding sheet has come loose and seems to be flapping about:

RNC_MGWR_663_Castlerea_6_Sept_1957 | [Photographer: Robin N … | Flickr

RNC_MGWR_663_Castlerea_6_Sept_1957 (2) | [Photographer: Robi… | Flickr

The loco is still in steam and in use. A few months later it was withdrawn and sat on the scrap line in Athlone with that cladding even more bent out of shape:

AEB_MGWR_663_582_Athlone_16_June_1958 | [Photographer: Antho… | Flickr

What a wreck! 

 

Note that 663 above carried a round-top boiler but had the larger diameter, waisted smokebox normally seen on the Belpaire boilered locos. It's quite a different shape to the almost flat-sided smokeboxes on 654 and 655:

 

[Mol_PMB]

Back to Quartertown Mill, I've been playing with the CAD and laser-cutter to rough out a platform and mill building shape.

I was delighted to find that a local stationers stocks good quality 1.5mm card for a few quid per A1 sheet, which is ideal material for this sort of exercise.

This is truly a job for the lazy man's scalpel!

I'll do similar rough mockups of the other buildings to get a feel for how they look, and if the layout seems balanced. At present I've just estimated dimensions from maps and photos, so there is certainly scope for some tweaks. 

Once I'm happy I can use the rough CAD as a basis for the more detailed and robust structures. 

[Mayner]

On 18/11/2025 at 8:24 PM, Mol_PMB said:

I'm still working on sourcing wheels - I've found some driving wheels but the leading wheelset (and perhaps the tender wheelsets) may need to be secondhand off ebay. And then I need longer square-ended axles; I have some ideas how to do this but need to make a jig first.  

 

Ultrascale wheels are probably the best option if you are able to accept the long lead time (my last order fulfilled within 6mths), supplied to order complete with axle set for 21mm gauge, a decent crankpin system and no risk of tyres coming adrift from the wheel centre unlike AGW driving wheels, Sharman wheels next best alternative if you can source a set (possibly Brassmasters). 

Most of my older 25+year old 21mm gauge steam outline locos fitted with Sharman wheels, Gibson on more recent locos, I ran into a problem with driving wheels coming adrift from the centres during assembly and AGW steel crankpins ringing off. I now remove the tyres from the centre, de-grease,then re-assemble securing with Loctite, I use 14BA c/s bolt as crankpin, AGW crankpin bush and secure with brass 14BA nut, worked without a problem for 25 years!

Most of my 21mm gauge diesels run on Ultrascale wheel sets with b-b set at 19.3. 19.3 B-B works with AGW OO/EM profile wheels,  but 19.5 b-b with Sharman type B wheels which have a narrower tyre width than AGW or Ulrascale OO/EM profile wheels.

I seem to have managed without a wheel quartering jig before buying a GW quartering jig about 20 or so years ago https://www.gw-models.com/product/wheel-press-quartering-jig/  been worthwhile having assembled several locos with press-fit wheels and hopefullyseveral more.