Horsetan

At last night's monthly meeting of the North London Group of P4 modellers, we had a lecture demonstration put on by visiting lecturer David Barham, who explained the state of CAD and 3D printing today.

He displayed samples of his work, including an ex-Great Eastern Railway J17 0-6-0 kit he is developing for Brassmasters - it looked that good, I signed up for one.

Also of interest was a sample of 3D-printed trackwork known as PlugTrack - this is a system of 3D sleepers and chairs that simply plug into rectangular holes in the sleepers. The system is derived from Martyn Wynne's famous Templot software. I thought it offered potential for Irish 21mm gauge track building.

Frighteningly good stuff.

7 hours ago, jhb171achill said:

Yes, they were very far from picturesque! One of the most ungainly looking steam locomotives I’ve ever seen….

They look similar to some of the engines built for railways in South Wales. 

The other 290+ drawings in that archive are fascinating. 

35 minutes ago, Galteemore said:

@WRENNEIREmay weigh in here, but my own understanding is that these are production over/runs or maybe seconds. This is probably the supplier 

Similar things used to happen with Bachmann and Bachmann-Liliput models. 

On 24/2/2024 at 10:11 PM, Horsetan said:

I think we might have a partial solution in the form of this brass tube - conventional P4 coach disc wheels could be mounted on this, and the 1.5mm pinpoint axle (if IRM have spares of part no.84 available) would telescope inside it.... Alternative insulated centre tubes cut to the wider gauge could then finish off the converted set.

I've discovered that Alan Gibson Workshop produces electrically conductive coach wheels, plus bushes for 1.5mm axles (hopefully the bushes are 2mm o/d, which means they can be pressed straight into the wheels).

6 minutes ago, jhb171achill said:

... we’d build one new Drumm train for Eamonn Ryan to travel about in.

The batteries would have to be programmed to run out just short of the destination 

2 hours ago, Gabhal Luimnigh said:

With all the money in the world! I would love to see a narrow gauge rail system to all the remote villages in the country linking to a rail system covering each large town and city properly.

Presumably this would include wholesale demolition of all properties and structures that were built on the original formations.....

1 hour ago, Flying Snail said:

Excellent - glad to hear it!!!

All good here, thanks, and the grey cells are already working out the least painful way of installing new wheels for 21mm gauge.

56 minutes ago, Horsetan said:

...One thing I note is that the conversion to 21mm gauge (P4 profile wheels) may not be completely straightforward, as the IRM bogie wheels work on a split-axle principle, with the wheels being an interference fit on 1.5mm dia stub axles which then plug in either side of the insulated centre tube. Conventional P4 wheels are generally mounted on 2mm dia axles and if these were swapped straight in, then the lighting function will be lost as the P4 wheels tend to be plastic-centred.

Somewhere in the bombsite that is my worktop, I have a pack of the old Exactoscale P4 coach wheels which - unlike the conventional type - were designed to mount on their own 1mm dia axles. This is going to require a bit of lateral thinking....

I think we might have a partial solution in the form of this brass tube - conventional P4 coach disc wheels could be mounted on this, and the 1.5mm pinpoint axle (if IRM have spares of part no.84 available) would telescope inside it.... Alternative insulated centre tubes cut to the wider gauge could then finish off the converted set.

4 minutes ago, Galteemore said:

Thanks - thought that would be the case unless separate 21mm brake mouldings were included. It’s worth it all in the end, we tell ourselves….

When all's said and done, it all helps to make you think a bit harder and develop your own methods to get round the problem. That's modelling.

Having said that, when Dapol brought out their Class 52 Western diesel-hydraulic, the bogies worked on the same split axle / stub axle principle. To convert it to P4, Ultrascale produced a limited batch of P4 wheels with the stub axles already fitted, and the wheels themselves were non-insulated. They weren't cheap, at 60 quid for 12 specially-produced disc wheels, but they worked. Thereafter the model performed the same way that Dapol designed it to.

I'm not sure Ultrascale would do the same again for a limited number of 21mm gauge coach conversions - I can see it would be an expensive exercise.

5 minutes ago, Galteemore said:

Interesting HT.How do the brake shoes work for 21mm? 

They won't work on 21mm gauge without cutting and splicing-in new inserts to take up the wider spacing.

However, that's relatively minor compared to what will be required to install new wheels (and axles).

The Murphy Models Mk2s are much more straightforward in that respect, but will themselves need to have the bogie frames widened to match the IRM overall width.

The parts diagrams are spectacular....

....and so are the full-width bogies....

One thing I note is that the conversion to 21mm gauge (P4 profile wheels) may not be completely straightforward, as the IRM bogie wheels work on a split-axle principle, with the wheels being an interference fit on 1.5mm dia stub axles which then plug in either side of the insulated centre tube. Conventional P4 wheels are generally mounted on 2mm dia axles and if these were swapped straight in, then the lighting function will be lost as the P4 wheels tend to be plastic-centred.

Somewhere in the bombsite that is my worktop, I have a pack of the old Exactoscale P4 coach wheels which - unlike the conventional type - were designed to mount on their own 1mm dia axles. This is going to require a bit of lateral thinking....

 

On 22/2/2024 at 9:46 AM, Flying Snail said:

Did they survive intact????

Update: it looks like they did, so that's a relief.

Next job is to convert everything to 21mm gauge.

25 minutes ago, Galteemore said:

Thanks - sadly my RPSI knowledge has lapsed from the minute by minute currency I had in my childhood! There are a few spare boiler projects kicking around in GB so my synapses must have made a false connection … Going back to those RPSI days, when I basically travelled on any trip doing fundraising,  the carriage officer was Alan Edgar, who later built this superb 21mm Mogul 

 

 

Alan's Irish 21mm output is sublime

22 minutes ago, Galteemore said:

Yes, I am aware of that. My heart applauds the project. My head says a second WT would have been a more prudent use of the spare parts. These spares - the boiler and wheels - are the core of the second Jeep that the RPSI could - and would have - bought in 1971 had the funds been available. I was born in Carrickfergus in spring 1971 - only realised recently that a mile from the hospital a number of Jeeps still slumbered awaiting their appointment with the oxy torch. But I don’t want to disrupt @WRENNEIREs thread. Hopefully he’s got a 21mm WT to post!! 

The wheels and some of the motion were salvaged from no.54, I think. I don't think the RPSI managed to save a spare boiler, otherwise they wouldn't be building an all new boiler and firebox now.

Interesting to note that the driving wheel pattern is the same one used on the LMS Black Five. 

1 hour ago, Mayner said:

Mixture of the Good, the Not so Good and plain Ugly wagons.

Achieving consistent result with 3D resin printing can be challenging some prints that did not meet the expected standard but not bad enough to discard.

Seconds are marketed as seconds and nature of defect summarised.

https://jmdesignmodelrailways.com/collections/rtr-models

Presumably the more expensive ones are the ones with the fewest flaws!

2 hours ago, Galteemore said:

Lovely. IIRC 97 was also the last to exist and almost made it to preservation. 

RPSI have quietly made considerable strides over the last decade in building an all-new one.

On 22/2/2024 at 8:20 PM, David Holman said:

 .....Any ideas as to what to do about the bogie are welcome. One option might be the old fashioned one outlined by John Ahern 70 years ago. Another thought is to make it a          2-2-6-0 tank, fixing the inner pair of wheels on the bogie [but giving them plenty of side play] and making the front wheels into a pony truck.

 Either way, I really don't want to have to build a new chassis. 

Here's one way of doing it

My understanding is that the bogie frame itself should directly support the main chassis frames and be permitted to slide from side-to-side, and not permitted any vertical movement. Only the bogie axles themselves should be allowed to go up and down.

Chris Pendlenton explains his bogie principles here - he's one of the few who understands how a model bogie should work, and how you get there.

On 21/2/2024 at 9:33 AM, Bob49 said:

I might have been tempted to used either KDs or Greenwich couplings as they are less obtrusive.

Branchlines does a fret for the central buffer, chopper-type couplings.

2 hours ago, Flying Snail said:

Did they survive intact????

I haven't had time this week to open the wreck of the parcel, but will get round to it on Saturday. It's currently sitting there, looking like the elephant in the room.

On 21/2/2024 at 7:25 AM, David Holman said:

Whoever built all these certainly knew what they were doing. Single maker or more than one/separate painter? 

Interestingly, having looked at all the photos so far, it does look to me like there's a slight variation in the depth of the wheel flanges amongst some of the models. 

On 20/2/2024 at 12:38 PM, DJ Dangerous said:

I wonder if they'll commission one through IRM...

Has anyone dared to shorten the IRM "A" into an approximation of a "C"?

56 minutes ago, Brack said:

I recall the gardai telling us to go a different way back to the flat than through fatima mansions one night... I think they were watching/staking out something. Likewise Dolphins barn could be hairy, and out inchicore way...

My cousin's mental alarm bells went off when he found out I was walking from the flat in Bow Bridge Place, through St. James and into the city centre. I only did that because it was more reliable than waiting for a bus. I could have walked out via Heuston and along the quays as an alternative.

The other thing my cousin told me was never to park my Fiat Punto in Ballyfermot as it was unlikely I'd see it again if I did. 

14 minutes ago, Brack said:

When I lived there (2001-3) I can think of some intact unused track in the middle of dublin next to a major tourist attraction, with surviving original stock and locos which mightve been restored fairly easily.

 

Guinness presumably not interested?

I was frequently in the same area between 1998 and 2003 (and may even have walked past you without knowing; who knows!?) and my cousin - at the time a junior doctor at St. James - kept telling me I was lucky not to end up as one of his daily patients since he often had to patch up those who had either been assaulted, stabbed, or otherwise injured due to general inebriation.

48 minutes ago, jhb171achill said:

What on earth is "Ulster broth"? Something that foams from the mouth of Paisleyite preachers on the Sobboth?

Ulcer sez no!

12 hours ago, WRENNEIRE said:

Enjoy

 

Phwoaarrr