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

Mol_PMB · November 13

Starting anew in Irish 4mm scale modelling, I'm considering the gauge question. I thought I'd do some experiments to see how easy or hard it was to regauge rolling stock to 21mm, before making a final decision.

Of course it's more complicated than just the gauge. There are different wheel standards and back-to-backs to consider, which seems a bit of a minefield! For now I'm going to see what's possible by re-using the existing wheelsets.

Anyway, I started at the relatively cheap end of the scale and bought some spare IRM Y33 bogies as a starting point. It was fairly easy to remove the wheelsets and I was able to tap the axles through the wheels to achieve a 19.2mm back-to-back (which is one of the dimensions I've seen quoted). Assembling the wheelsets back into the bogies was straightforward and the wheels then had a much better alignment to the axleboxes and the representation of brake gear. This photo shows before and after on my dual gauge track:

I don't really have a use for these bogies at present, but they will be good for testing track as the wheel/rail interface is quite visible. I might re-gauge the other one and connect them with a strip of perspex for that purpose.

I'll describe the second project in the next post.

Edited November 13 by Mol_PMB
correcting typo

Mol_PMB · November 13

Project number 2 was an IRM corrugated open wagon.

Again, it was reasonably straightforward to extract the wheelsets and tap the wheels along the axles. However, the maximum back-to-back I could achieve was 19.0mm - any more than this and the wheels rubbed on the back of the W iron mouldings. To achieve a largere BTB would require a thinner, more finescale wheel profile.

On this model, the brake shoes are positioned to align with the 16.5mm gauge wheels, foul the wheel flanges when the wheels are set to 21mm gauge. However, the brake gear is very simple (as per the prototype) and I found that by levering with a tiny screwdriver I could release the brake hanger from its mounting hole in the chassis.

I then used a small drill bit to slightly enlarge the tapered slot next to the hole, so I could push the brake hanger back in there. With a small tweak to the brake push rod safety loop, the brake shoe aligned with the wheel quite well:

It's not perfect but it looks fine from normal viewing angles. In due course I'll apply a tiny blob of glue to hold it in the new position:

I suspect that modifying the brakes on the forthcoming vac-fitted H van will be much more challenging!

Next I realised that the buffer spacing looked very wrong on the broad gauge track. On this model, the buffers are set to match GB rolling stock for some reason, and they ought to be further apart for an Irish vehicle. I decided to take the plunge and try to change them. Also, I wanted to represent a wagon retro-fitted with the larger buffers, like this one:

I was unable to remove the old buffers without damaging them badly. I temporarily removed the wagon body and sanded down the remains, and then re-drilled new larger holes in a better position:

The buffers I had in stock looked about right until I held them up against the wagon headstock, and then they looked too big! But looking back at the prototype photo the base of the buffers is a fair bit taller than the headstock section. I'll have a think about it and see if I can find an alternative buffer if I decide these ones aren't right. Any suggestions welcome!

In the meantime, here's a view of the bufferless wagon on the broad gauge track:

I've ordered a couple of wagon kits which I plan to build to 21mm gauge - that may be easier than modifying RTR where suitable kits are available.

My main stumbling block for the kits is the broad gauge wheelsets. I think I'll try the dodge of cutting the axle in half and sleeving it.

Please tell me if there are better approaches to re-gauging, or if you have advice on back-to-back, finer wheel profiles or sourcing wheelsets - I feel I'm stumbling a bit on the path to 21mm...

Galteemore · November 13

All of us broad gaugers stumble a bit! Looking good so far. Sleeving axles is probably a fairly cost effective way to go about it. And brakes are a pain. Some 7mm Irish kits are designed on the - quite reasonable - assumption that most people will build to 32mm, and the fold up brake gear designed accordingly !

Edited November 13 by Galteemore

Mol_PMB · November 13

I have done the deed with the buffers, and I think it looks satisfactory.

It's very hard to get buffers perfectly straight, but I take comfort from the fact that the factory-fitted ones aren't 100% perfect either!

I have enough of these buffers to convert another wagon, so I might do that tomorrow or Friday.

The buffers I've used are X6495 Hornby Sprung Tender Buffers for Class B1. They're not a perfect match to the CIE self-contained buffers but they're about right.

Photo of the real thing from Neil Smith, showing the larger type buffers and how near they are to the outer edge of the headstock:

David Holman · November 14

Am sure someone can give a definitive measurement, but seem to remember 6 feet or even 6'3 is the buffer spacing.

As for axles, I use 4mm scale wheels on my 7mm scale, 21mm narrow gauge models, where the standard axle is 2mm diameter. Hence it is a simple matter to fit new axles from 2mm brass wire. The pin point ends are easily made by twirling the axle against a slitting disc in a mini drill, while using brass means the axles aren't attracted to the permanent or electro magnets I use for uncoupling. Have found P4 axles aren't long enough.

Speaking of P4, have found that 4mm finescale/EM standards work perfectly well for 21mm gauge, without going the extra step.

Another option, rarely mentioned, is "Irish EM". I only came across it when looking on Templot for a set of points drawings, but it uses a 20.2mm track gauge - a similar proportion for 18.2 v 18.83mm standard gauge. On one level, one could argue why bother, but thinking about it, it might just mean the back to back will be just that bit smaller to avoid wholesale rebuilding of rtr chassis. I use 19.2mm back to backs and have found that if it is out by as little as 0.2mm, it causes problems on point crossings or Vs. This is with the standard one millimetre flangeways used in finescale 00 and EM.

The wagons look great in the right gauge, by the way, but (if it isn't already in your plans), a couple of points will be essential on your text track to check whatever clearances and standards you use. Love the overall approach too as it could well point the way to more folk trying broad gauge.

Mol_PMB · November 14

Many thanks, that’s really helpful and plenty for me to think about. I will need to have some pointwork, but not sure what approach to use at present.

Buffer spacing is 6’3” for the CIE wagons, whereas GB standard gauge is 5’7.5”, a 7.5” difference, similar to the track gauge increase.

Brendan8056 · November 14

Welcome back to the world of Irish modelling.

I have posted various bits here about re-gauging to 21mm. Rather than repeat myself you can hopefully search for my posts. Also I would suggest subscribing to "New Irish Lines", if you have not already done this. The latest releases from IRM and Murphy Models are 21mm friendly. As David Holman does, I also make my own axles using a drill and some files, very little skill is needed, if I can do it.

derek · November 14

Oh Jesus! Not buffer spacings again. I'm saying nothing anyway- got into trouble last time.

Mol_PMB · November 14

16 minutes ago, derek said:

Oh Jesus! Not buffer spacings again. I'm saying nothing anyway- got into trouble last time.

Oh dear, I don't want to rub salt in a wound or upset IRM! I was trying to show how to make them right rather than complaining about them being wrong.

I'm hoping that from the pack of 3 wagons I may be able to salvage 4 of the supplied buffers in adequate condition to re-fit to one of the wagons, with the other two having the new larger buffers. But that may be optimistic!

I've pre-ordered some H vans and they will be much more of a challenge as they didn't have their buffers replaced with the larger ones.

Anyway, the next task on the corrugated wagons is weathering, which is always fun. Bring on the filth!

Mol

derek · November 14

Just now, Mol_PMB said:

Oh dear, I don't want to rub salt in a wound or upset IRM! I was trying to show how to make them right rather than complaining about them being wrong.

I'm hoping that from the pack of 3 wagons I may be able to salvage 4 of the supplied buffers in adequate condition to re-fit to one of the wagons, with the other two having the new larger buffers. But that may be optimistic!

I've pre-ordered some H vans and they will be much more of a challenge as they didn't have their buffers replaced with the larger ones.

Anyway, the next task on the corrugated wagons is weathering, which is always fun. Bring on the filth!

Mol

You're fine @Mol_PMB, I was only having a laugh. When I said a couple months ago that there is more to worry about in the world than fractions of millimetres in buffer spacings, my post was removed. Still not sure why. At the time the lads were getting a bit flustered on the subject. Can I just say you are a total mine of information, well done

murphaph · November 15

They look fabulous with the Hornby buffers. Great work!

Mol_PMB · November 15

I made a start on the second corrugated wagon tonight, and experimented to see if I could remove the buffers without destroying them, so that I could re-use them but positioned at the correct spacing. After a few false starts I think I am getting somewhere with this.

This is the technique I used. First, use a tiny jewellers' screwdriver to push the buffer head out from the rear. If you have enough hands you can pull on the other end too. When it comes out, try not to lose the buffer head or the tiny spring.

Then insert a piece of 2mm diameter tube or rod into the front of the buffer guide. Wiggle it around gently, and hopefully the buffer guide will come loose from the headstock:

I then added some plastic strip to the outer edge of the moulded buffer base, and when that was stuck well I sanded down the faces. I marked the new holes (25mm centres) and drilled them.

However, there was quite a recess where the old buffer holes were, so I inserted some 1mm plastic rod with a dab of filler round it. I'm waiting for that to set before I sand it down flush.

The back of the buffers will need to be smoothed off too, before I glue them back on.

If I can make this work, then it should also work on the H vans and I might be tempted to order some more!

TimO · November 15

I’ll be very interested to follow how you progress with these modifications; seems like a case for a good jig to line up everything.

Mol_PMB · November 16

I was able to line up and refit the old buffers fairly well. I fitted the guides first and then put in the sprung heads. On one of them the sprung head tends to stick in when compressed, but the others are all fine. I'm reasonably happy with the result.

I'm considering changing the brake gear on this wagon, to the alternative 4-shoe type fitted to some of the corrugated wagons. But to do that I'll need some parts from the H van underframes which won't be here for a while. So for now it can keep the standard brakes.

I then tackled the third wagon, and managed to salvage all the old buffers and replace them with the larger Hornby ones, the same process I used on the first wagon except that I now have a stock of spare IRM buffers for future conversions.

Here are the three wagons together on the photo plank. Tomorrow when I have daylight again, I'll make a start on the weathering of these three wagons.

DJ Dangerous · November 17

Excellent job on re-spacing the buffers, @Mol_PMB! @MAL will be most interested in these few posts, too.

Surprising how much of a difference the re-spacing makes to the overall impact. The IRM Bulleids are a really lovely wagon, and you've taken them to the level they deserve with that mod.

A Mol-Mod, I guess...

murphaph · November 17

A side by side before and after of the buffer mod would be great if you haven't done them all yet!

ttc0169 · November 17

The 1:1 version…..at Maam cross station

DJ Dangerous · November 17

22 minutes ago, murphaph said:

A side by side before and after of the buffer mod would be great if you haven't done them all yet!

Great idea, would love to see that.

Almost sure, but not completely sure, that @Garfield said a few months back that IRM Bulleid buffers may be available as spares in the future, as are Accurascale buffers.

The Accurascale buffers translate into Spanish as tampons, so hopefully the IRM ones don't get the same treatment!

7 minutes ago, ttc0169 said:

The 1:1 version…..at Maam cross station

Now, could you move the buffers inwards a few inches and take some more pics, please???

Mol_PMB · November 17

28 minutes ago, murphaph said:

A side by side before and after of the buffer mod would be great if you haven't done them all yet!

3 minutes ago, DJ Dangerous said:

Great idea, would love to see that.

Almost sure, but not completely sure, that @Garfield said a few months back that IRM Bulleid buffers may be available as spares in the future, as are Accurascale buffers.

The Accurascale buffers translate into Spanish as tampons, so hopefully the IRM ones don't get the same treatment!

Now, could you move the buffers inwards a few inches and take some more pics, please???

I'm sorry, it's too late! I only bought 3 corrugated wagons, and I've now converted all of them. I didn't take a side-by-side photo, the best I can offer is this one from earlier in the thread:

However, if you can be patient, I have increased my H van order to 6 wagons, so I'll have plenty of them to show comparisons.

Having now trawled through the wagons in the IRRS archive, I now think there are a total of 6 buffer types used on the triangulated wagon underframes:

Small buffers with two ribs each side (this is the type fitted by IRM)
Small buffers with one rib each side
Small buffers with two ribs each side, on spacer block (green vans only)
Small buffers with one rib each side, on spacer block (green vans only)
Large buffers (this is the type I'm approximating with the Hornby loco buffers)
Very long large buffers with step on top

The one at Maam Cross has the second-largest type. (thanks for the pics BTW)

I think some wagons were built with the first, second and fifth types, the others were later modifications.

I plan to modify two of the H vans to former green vans with the buffer spacers, one van with the normal body type (in brown) and one of a Palvan type (in grey), as I have found evidence that some survived into those liveries.

It would be great if IRM could produce some spare bits!

At the moment I am working on weathering the three corrugated opens, but there's a lot more to do yet.

Mol_PMB · Tuesday at 21:37

Weathering continues. It's a slow process as I have to do one side at a time, and let it dry throroughly before applying the next layer. I'd say I'm about half way there with them. One is particularly heavily weathered, the other two are more moderate.

At the moment it's all too contrasty, but a dark wash and a light spray of dirt will blend it back together.

I bought a couple of EM gauge wagon wheelsets which have a finer profile than the OO ones. I think if I swap them into the corrugated wagons, I'll be able to get the 19.2mm BTB without the wheels rubbing on the W irons. Of course the EM axles are the wrong length...

I wonder whether IRM could be persuaded to sell replacement 21mm gauge wheelsets?

In other news, some wagon kits have arrived, and there will be much swapping of parts to achieve the desired results!

I have a Parkside PC08A, PC25 and PC65, a Cambrian C107, and C105, plus a selection of spare buffers and brake gear parts. I'm hoping these can be mixed up to produce a GNR ex-cement van, a CIE palvan, and two NIR ex-Courtaulds wagons.

More on them once the corrugated opens are finished.

Mol_PMB · Wednesday at 20:24

Weathering stages on the corrugated wagons continue and should be complete tomorrow. Now that I've got the various kits to play with I should have enough parts to complete the alternative brake gear on one of them - a job for tomorrow.

In the meantime I have started a project that may be familiar to many: an ex-GNR cement van. I've convinced myself by lots of scaling off photos that the van body of the GNR van is the same size as the BR vans - rather than the slightly shorter and wider Irish standard. That makes things easier! I'm using the Parkside PC08A kit as a basis, but I've swapped the solebars from a Parkside PC25 as they have the right sort of axlebox (but the wrong brakes). I needed to add extra V hangers anyway so that was no great problem, and the PC08A solebars have an alternative destiny...

I've cut and sanded off the buffers and re-drilled at Irish spacing. I have some spare RCH buffers I can rob from a Cambrian chassis kit. The holes for the vents have been filled with a slice of plasticard and some filler which I'll deal with tomorrow once it's set hard. In the meantime I've added a load of little etched details to the sides, to replace the moulded bits that weren't quite right. These came from the Mainly Trains 'wagon detailing components' etch, the Cambrian etched tiebars, and the 51L 'Brake levers, V's and guides' etch BLGVB. I'll be using more parts off these later...

Photo of a prototype from Jeremy Chapter on Flickr:

I am considering getting some rivet transfers from Railtec to add the rivets/bolts around the edge of the doors.

Many of these vans seem to have acquired strips across the roof, as in the photo above, but they weren't built with them and some survived to the end without. I'm quite tempted to model the one shown in Neil Smith's photo here, dated 1981. In this pair it's the H van that has the strips on the roof, not the GN van!

The wheels supplied with this kit have a finer profile than the ones in the IRM corrugated wagon - the tyre width is 2.2mm rather than 2.8mm. This should mean there's no difficulty in setting them to 21mm gauge, except that I'll need to lengthen the axle. In fact the wheel profile matches that on the EM gauge wheelsets I bought. So I think I'll end up using some wheels of this type to replace the IRM ones in the corrugated wagons.

Not the best photo but this shows the finer profile of the wheels in the Parkside kit compared to those in the IRM corrugated wagon:

Anyway, more tomorrow.

Mol_PMB · Thursday at 11:35

I've been working on adding the different brakes to one of the corrugated wagons. Some of the triangulated underframe wagons had a 4-shoe brake with the brakes mounted outboard of the wheels. I do like little variations in my fleet.

Here are some images showing the arrangement; these are in the public domain from Ernie on Flickr, but there are clearer shots on the IRRS archive.