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5 hours ago, Jol Wilkinson said:

I model the LNWR in P4 and have only ever used compensation for locos. The 4-4-2 Precursor tank shown has a rigid rear driven axle and "pivoted" front axle. It picks up only on the driving axles (PB strip wiper pickups with brass contact pads against steel tyres) and will run properly all weekend at a show without needing cleaning. The 0-6-2 Watford Tank has a "rigid" rear driven axle and a compensating beam between the centre and front coupled axles. The rear pony truck is lightly "weighted" by a longitudinal wire spring bearing on it.

 

I've considered springing and CSBs over the years but was never happy about the former and often found that the the latter needed a redesign of the kit frames and spacer to accommodate it. Hence I stuck with compensation (although some of my locos combine compensated driving/coupled wheels with sprung bogies, radial trucks or pony trucks.

 

Although CSB are claimed to provide much smoother running, I have found that, provided the track is well built, then a smooth "ride" will result. 

 

 

Precursor and Watford Tanks.jpg

Hello Jol, thank you for the post, very encouraging. I am of course familiar with your modelling from many other threads and from London Road, but I didn't know of your confirmed preference for compensation. Both locos in your picture look absolutely superb; I've always liked the Precursor and may yet build one, but my main area is the GNR and LNER so I try not to let 'foreign' stock get too numerous. That being said, I have an LRM Samson in my pile (early locos sometimes catch my eye) and I've just ordered a Teutonic, because the motion looks fascinating and there's something uniquely graceful about the lines of the loco in profile. 

 

A fixed rear and pivoted front driving axles are exactly what I had come to the conclusion would work with my C12, so I'm very pleased to hear you did the same. Did you apply any kind of compensation to the front bogie? I'm considering pivoting that too and linking it - using a rubbing plate - to the pivoted front driving axle.

 

My layout has very tight curves so not only will the front bogie need some management, but the rear wheels may be a concern and I haven't yet worked out what to do with them. I may try something sprung, so I'm also interested to hear that you combine compensation and springing. I think they may need more sideways movement than the chassis allows, but what I'll be able to hide without it looking too un-prototypical I'm not yet sure.

 

Brass contact pads on PB strip sounds interesting too: so far, I've only used plain PB wire which works well for me most of the time but does need a little adjustment from time to time. I think perhaps strip might be more stable...

 

As to springing and CSB, I'm reading through a lot of material on that currently and I do think it may not provide improvement proportional to the extra complexity and construction time, but I am going to try some builds out of curiosity and to see them working. I expect I'll get over my fascination once I've tried it... Either that or I'll be one of those very zealous converts :rolleyes:

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Coal rails, steps, balance pipes and I've pretty much reached the limit of what can be built as separate sub-assemblies:

1195022554_LRMC1220201001(2).jpg.b6bad78a5cc060e96183f6239f4f0fb4.jpg

 

1219255558_LRMC1220201001(1).jpg.2c38f39256b19d1c89ce6976018f9392.jpg

 

One interesting side effect of building this way - instead of fixing each sub-assembly to a single main construction - is that I've paid more attention to how attaching each section will interact with attaching the neighbouring pieces. On previous builds (of all types of rolling stock) I've come across situations where earlier construction has caused issues with fitting a part in later. Here however, there's ample chance to look at how things will combine, and which spots will need particular attention: the boiler and it's associated parts are a good example...

 

But for the time being, all these pieces will be put to one side and work will commence on the chassis...

 

And I really should do a bit more on the GNR resin coach too: I've been putting off cutting out all the windows:no2:

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Hi Chas,

the Precursor Tank in the photo is from a LRM kit when they were supplied with a Brassmasters chassis. This was based on the BM Precursor/George V 4-4-0 chassis but they never got around to doing the body kit so LRM used then for a while.

 

The chassis incorporates a compensated bogie, fitted to swivelling front end frames (the split is behind the front footsteps). This has only really run on London Road that hasn't really got any curves but has run on Tony Montgomery's Ambergate without any issues but I don't know what the track radius is on that. 

 

When the BM chassis kit became an uneconomical proposition for John Redrup at LRM I designed a new chassis for him. This has rigid frames, tapered front and rear, the front bogie as sprung axles and the rear radial truck also has springing as on the Watford Tank in my photo. I designed it for 2'6" curves, but given the loco length couldn't get clearance for anything much tighter. Apart from the test etches I haven't build a working version for myself yet but I believe that there is one running on Clarendon which has a rather tight curve into the station. P4 gives less clearance than 00 or EM. I build the chassis first to get it running right and then build up the body, checking for clearance as I go.

 

I used the same sprung bogie concept for several LRM loco kits I designed for John. The bogie frames have a rubbing plate that supports the front of the main frames and the bogie axles are carried in sprung tubes with guides. The mix of compensated and sprung tends to be a pragmatic choice, usually with springing on carrying axles. The only locos I have built with compensation between driven and carrying axles have been 2-4-0 and 2-4-2T with a beam between the front coupled and carrying axles. When I designed the LNWR 4' 6" Tank for LRM however, I put radial trucks with light central springing at each end so that  it was all included in the design.

 

The Teutonic also uses the same radial truck at the front. The kit is designed to drive the rear axle only so I have to build the 2000g tender frames for mine with "floating" front and centre axles and will support the front of the tender on the drag beam for more adhesion. I know of one modeller who assembled his 00 version with small motors driving each axle separately. Unfortunately a detached retina in my right eye and protracted treatment has stopped progress since April. So I have to satisfy myself with looking at great model building like yours.

 

Jol

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4 hours ago, Jol Wilkinson said:

Hi Chas,

the Precursor Tank in the photo is from a LRM kit when they were supplied with a Brassmasters chassis. This was based on the BM Precursor/George V 4-4-0 chassis but they never got around to doing the body kit so LRM used then for a while.

 

The chassis incorporates a compensated bogie, fitted to swivelling front end frames (the split is behind the front footsteps). This has only really run on London Road that hasn't really got any curves but has run on Tony Montgomery's Ambergate without any issues but I don't know what the track radius is on that. 

 

When the BM chassis kit became an uneconomical proposition for John Redrup at LRM I designed a new chassis for him. This has rigid frames, tapered front and rear, the front bogie as sprung axles and the rear radial truck also has springing as on the Watford Tank in my photo. I designed it for 2'6" curves, but given the loco length couldn't get clearance for anything much tighter. Apart from the test etches I haven't build a working version for myself yet but I believe that there is one running on Clarendon which has a rather tight curve into the station. P4 gives less clearance than 00 or EM. I build the chassis first to get it running right and then build up the body, checking for clearance as I go.

 

I used the same sprung bogie concept for several LRM loco kits I designed for John. The bogie frames have a rubbing plate that supports the front of the main frames and the bogie axles are carried in sprung tubes with guides. The mix of compensated and sprung tends to be a pragmatic choice, usually with springing on carrying axles. The only locos I have built with compensation between driven and carrying axles have been 2-4-0 and 2-4-2T with a beam between the front coupled and carrying axles. When I designed the LNWR 4' 6" Tank for LRM however, I put radial trucks with light central springing at each end so that  it was all included in the design.

 

The Teutonic also uses the same radial truck at the front. The kit is designed to drive the rear axle only so I have to build the 2000g tender frames for mine with "floating" front and centre axles and will support the front of the tender on the drag beam for more adhesion. I know of one modeller who assembled his 00 version with small motors driving each axle separately. Unfortunately a detached retina in my right eye and protracted treatment has stopped progress since April. So I have to satisfy myself with looking at great model building like yours.

 

Jol

Hello Jol, thank you very much for the detailed answer, which I shall digest properly this evening; I just wanted to reply as soon as I read it though, to say how sorry I am to hear of your retina trouble. My grandfather had the same problem but that was in 1959, when treatment was considerably less advanced and successful as it is these days - I hope the treatment is going well and that you will soon be back to building, rather than just looking. 

Thank you for your kind words - I'm glad if my efforts help entertain you during your recovery; whenever I look at them I mainly see the faults and errors!

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Finally got going again on the Mousa resin GNR coach, cutting out all the windows:

1949955143_MousaGNRD12920201007(1).jpg.cdf746b50922e2e32c4e363faf813166.jpg

 

I decided to cut them all now, to a uniform size, fettling later as needed. I'm using glazing strips from Wizard models, 0.7mm thick, and realised as I offered them up that the sill depths vary, as you can see in the photo above. In addition, some have inner ridges that are quite well defined, some don't. I suspect that the glazing that would have been supplied with the kit may have been thinner, so I'll have to remove the inner ridges on the narrower sills, to allow the glazing to sit flush with the outer body surface. A quick test shows that it already does so on the windows with the deeper sills (the taller narrower ones) but not on the others.

The thicker body is one advantage this material has over brass; on the brass coaches I've built, I've been at pains to fix the glazing as closely as possible against the inner surface of the coach sides and the very thinness of the brass means you generally get away with it - or certainly at layout viewing distances. This coach should hopefully have truly flush glazing however...

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Hi Chas,

 

I'm building a D277 brake third and a 6 wheeler to D245.  The supplied glazing is 0.3mm.  I haven't tried fitting it yet as I want to apply the transfers first and then a coat of matt varnish, leaving glazing and grab handles to last.

 

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1 hour ago, 2750Papyrus said:

Hi Chas,

 

I'm building a D277 brake third and a 6 wheeler to D245.  The supplied glazing is 0.3mm.  I haven't tried fitting it yet as I want to apply the transfers first and then a coat of matt varnish, leaving glazing and grab handles to last.

 

 

Hello, thank you for the reply; I thought what comes supplied with the kit must be thinner and I shall get some 0.3mm.

I too am leaving the glazing and grab handles until last, but I wanted to get the cutting out of the glazing out of the way now (if I have something tedious or a bit boring to be done, I always like getting it done as quickly as possible, old habits etc...); interestingly, some of the windows - the deeper ones - seem to suit using the 0.7mm, so once I have the 0.3mm as well I can pick and choose :).

Edit: checking through what I have in stock, the thickest glazing (aside from the Wizard 0.7mm) is 0.25mm and that - at only 0.05mm less than the Mousa-supplied 0.3mm - seems very thin to stay rigid in separately cut panes like this.

Does it look too thin to you, 2750Papyrus? Am I over-thinking it?

I know from experience that 0.25mm works fine in strips fixed inside a thin brass coach side, but getting vertical uniformity here, where the insides of some of the window apertures have come out slightly differently from each other in the moulding process, might be tricky. I've asked again about getting the 0.3mm that comes with the kit, but in the meantime I've ordered some 0.4mm, in hopes that will be the Golden Mean: thin enough to sit properly against the retaining ridges in the shallower windows, thick enough to stand flat...:unsure:

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Hi Chas,  I don't know if you have assembly instructions with your kit.  Those for my D277 say that the windows are designed to be fitted from the outside and recommend taking care when removing flash from the reveals.  I haven't tried fitting windows yet.

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On 09/10/2020 at 12:58, 2750Papyrus said:

Hi Chas,  I don't know if you have assembly instructions with your kit.  Those for my D277 say that the windows are designed to be fitted from the outside and recommend taking care when removing flash from the reveals.  I haven't tried fitting windows yet.

 

I have the general assembly instructions downloaded from Bill's website so I read the same thing. There is a thin dividing line (no pun intended) on some of these reveals between flash and what I take to be inner retaining ridges or raised lines. No problem though; I now have some 0.4mm on the way and found I have 0.25mm in stock, so I shall set the windows aside until later in the build for now and, when the times comes to turn back to them, I'll move between the various thicknesses according to what seems to fit best.

Next will be the underframe and roof detail.

Also today I've been looking at the LRM C12 frames and drive train, while I plan the compensation arrangements. I've pretty much decided to go with rigid rear and pivoted front driving axles (thank you again to Jol Wilkinson for recommending that arrangement, as have many other people of course). That leaves some further planning for the bogie (which I intend to have deriving some compensation from the same beam as the front driving axle) and the rear trailing wheels (which will need enough sideplay / movement to negotiate my layout's curves. So no pics at the moment - unless you'd like to see a scan of my brain, showing the electrical activity this is generating... :read:

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On 02/10/2020 at 11:29, Jol Wilkinson said:

Hi Chas,

the Precursor Tank in the photo is from a LRM kit when they were supplied with a Brassmasters chassis. This was based on the BM Precursor/George V 4-4-0 chassis but they never got around to doing the body kit so LRM used then for a while.

 

The chassis incorporates a compensated bogie, fitted to swivelling front end frames (the split is behind the front footsteps)...

 

Jol

Hello Jol, just found photos and a scan of the BM instructions for the BM chassis with the swivelling front end, on your RM Web "LNWR 4mm rolling stock for London Road -it's all packed away" thread; I also read through the related posts, including your note that you added a centralising/springing wire to the top of the front frames to keep the front end under control. I was very interested to see how the pivoted front end works (I'd spent some time after you wrote about it above, trying to picture how it could be done) and I'd say it's definitely a very useful tool to have in the box for possible future use. I can quite imagine though why that centralising/springing wire would be needed. I was also very interested to see the near eye-level photo of your PT with the BM chassis, where you can clearly see the split in the frames, which makes very clear how extremely unobtrusive the join actually is! I know you've since moved away from this idea in your subsequent LRM chassis designs, but because I'm running models on a small layout with very tight curves, techniques like this are always of interest...

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Stop Press update: today's post brought this:

986389367_MousaGNRD12920201010glazing(1)-2.jpg.a2b57071950602acb0d16632d845435e.jpg

 

The missing glazing from the Mousa coach kit and it looks well worth waiting for! I've not seen glazing measured and marked out like this and it will reduce the fitting time a great deal. The lines are scored and the numbers and letters are also 'etched' into the surface, which looks like a useful process :good:.

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Chaz, you might not thank me for this but I've just seen a contemporary drawing and notes for your APOC tank which Mick Nicholson has kindly put online.   They're from Model Railway Constructor June 1943.  It gives the livery as 'solebar and all above red oxide, lettered white, underframe and all ironwork below solebar black'.

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5 hours ago, jwealleans said:

Chaz, you might not thank me for this but I've just seen a contemporary drawing and notes for your APOC tank which Mick Nicholson has kindly put online.   They're from Model Railway Constructor June 1943.  It gives the livery as 'solebar and all above red oxide, lettered white, underframe and all ironwork below solebar black'.

Hello Jonathan, how are you? Hope you're doing OK and managing to keep occupied...

Re. thanking you, 'yes and no' would be my answer I think! Thank you on the one hand as it's always interesting to learn more and because it's nice of you to have let me know, less of a 'thank you' because I agonised over this for some time and hoped I'd put the issue to bed (in my own mind at any rate:unsure:).

The SE Finecast instructions had given oxide for the tanks and everything else black, but I ground to a halt somewhat in trying to decide exactly where the divisions between the two colours should occur (tanks only? Really?) and when I looked online (and spent a long time searching for many similar types of tanker wagon photos and descriptions) I could only find one modelled example in that sort of colour scheme which I'm afraid I felt just didn't look convincing. I think from memory that example did follow what you've given there - solebar and up - but because that was different to the SEF instructions I hesitated, plus I didn't feel it looked quite right...

What I also found was a pretty wide variety of colour schemes in models, but from memory all the prototype photos seemed to be basically black (though I realise that may be because nobody was photographing them until very late in their lives, when earlier fancier colour schemes had long since sunk under coats of black paint and dirt). I decided on balance that black was the least likely to be wrong as these wagons certainly were black at some points in their lives, and it also looked fairly 'dignified', if you know what I mean.

So... interested to learn, but I'm not going to strip and repaint it :no2:.

 

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That's fair enough, Chas and probably what I would have said in your position.  I thought you'd almost certainly painted yours by now, so the main reason for posting was for anyone else who Googles their way to your build and reads up what you've done.  They can then make an informed decision.

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A fellow club member had an example of the APOC wagon - from the Wills kit I believe - he didn't know what it was and asked me to identify it. That led me to this informative topic:

from which I gathered that there were probably no more than half-a-dozen built and possibly only one. The fact that such an obscure wagon has been the subject of two kits seems to be down to it having had the misfortune to be the subject of a Roche drawing.

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18 hours ago, jwealleans said:

That's fair enough, Chas and probably what I would have said in your position.  I thought you'd almost certainly painted yours by now, so the main reason for posting was for anyone else who Googles their way to your build and reads up what you've done.  They can then make an informed decision.

Good point Jonathan; I think of myself as very inexperienced compared to many people on here and on LNER Info so I hadn't considered that anyone would look at what I'd posted for information, but the internet is a true democracy when it comes to the dissemination of information so I should be as careful as the next person! You're right that it's painted - photos of the finished model are one page back, at the start of page seven. I thought it turned out well and looks rather smart (a lot smarter than I thought it was going to look during the build) and it runs very well :).

16 hours ago, Compound2632 said:

A fellow club member had an example of the APOC wagon - from the Wills kit I believe - he didn't know what it was and asked me to identify it. That led me to this informative topic:

from which I gathered that there were probably no more than half-a-dozen built and possibly only one. The fact that such an obscure wagon has been the subject of two kits seems to be down to it having had the misfortune to be the subject of a Roche drawing.

 

Thank you - I too found that thread; there isn't actually a great deal on this vehicle online, but I definitely gained the impression that there was more than one originally built. From memory I think that's right that half a dozen were built, possibly in more than one pattern, but I think it may have been the case that a pair survived longer than the others and were later documented... I used some excellent photos on the Paul Bartlett wagons site for some of the detail that isn't included in the SE Finecast kit and I'm sure some of those photos show a pair.

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So... I've been devoting some thought to frame and chassis matters, as I prepare to step off the quayside of Rigid Frames and strike out into the sometimes choppy Compensation Seas (sorry:rolleyes:).

I've been wrestling with the best order in which to do things, so as to take maximum advantage of opportunities for accurate alignment.

Here are the frames as supplied (after detaching from the fret and a bit of cleaning up):

481920309_LRMC1220201014(3).jpg.715b0281d29bf6f084c0a529cbd70249.jpg

 

I know I'm far from being the first to consider these things and others have come up with their own solutions, but figuring things out for yourself is a good way to learn, so...

With the axle holes intended for rigid construction still in place, you have the means - using a jig - to achieve exact alignment of the frames, but the instructions - and most of the build photos I've seen - advise cutting out the hornguide openings before fixing the frames together. Also, it occurred to me that if the hornguide opening were to be removed on one side only, the opposite uncut side's rigid-chassis axle hole could be used to align the first hornguide being fixed in place. That first hornblock could then be temporarily fixed in its centre position (using the neighbouring rear fixed axle hole, as the rear driving axle is to remain fixed) and used to align its opposite hornguide. This would mean that the hornguide openings would have to be removed after the frames had been fixed together, but I think I can manage that, especially because they're 'perforated' already, so I wouldn't be cutting out the whole outline or worrying about extremely accurate straight lines...

Clearly the holes for the compensating beam should be drilled with flat frame pieces, and the hornguide openings for the trailing wheels can't assist in frame alignment and are going to have to come out anyway, so they may as well be removed before soldering the frames up.

So, my proposed order is:

1. Plan compensation beam pivot bar location and drill holes for it in the frames.

2. Remove trailing wheel hornguide openings.

3. Solder frames and spacers, using existing rigid-chassis axle holes to align in the jig.

4. Cut out the hornguide opening from one side of the front driving axle.

5. Solder in the first hornguide, using the rigid-chassis axle hole on the opposite side to align it.

6. Temporarily fix that first hornblock bearing on its centre line to prevent vertical movement, cut out the opposite hornguide opening and use the first hornblock bearing to align the second one.

 

If anyone can see anything I've missed which may be a problem, please let me know :unsure:.

 

Going back to the trailing wheels for a minute: I'm awaiting the arrival of an interesting little etch from London Road Models, a radial truck, originally part of some of their LNWR kits but now sold as a separate etch. I'd been scratching my head as to how to provide enough lateral movement to cope with the curves on my layout and I'd already realised I'd have to do something fairly drastic, when I came across discussion of these radial truck etches on Michael Edge's build thread. I realise that using them (or something similar) would be un-prototypical, but I'm hoping that when painted black and quietly tucked away under the rear of the loco, they won't be too obtrusive. The only other solution would be to use a pony truck and I think that might be rather more noticeable. In any case, they look very interesting and if they don't get used for this kit, they're bound to come in handy for another build in the future.

 

For the front bogie, I'm also awaiting another similar item from LRM, their LNWR sprung bogie (which is likewise now available separately). This is more for the purpose of seeing how it's constructed and possibly either using some parts in the C12 bogie, or using them as a pattern to construct something similar to fit the C12, as I've not built anything like that before...

 

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Roof 'furniture' added to the GNR D129:

1284736859_MousaGNRD12920201018(1).jpg.d3e903b715483184d74de3735e69e9cf.jpg

 

The sprue only had 12 vents but this coach has 14 (I'm guessing it's a standard sprue for different types of Howlden coach) so I used some MJT ones I had in stock.

The bogies are progressing too, photos in due course.

I've also been looking at the fixing between the chassis / floorpan and the body, which is done as the kit comes by one central fixing screw; I have to admit I'm not entirely happy with this as I've never used this kind of resin before and I can't help wondering about possible flexing or distortion with age (again with the belt and braces attitude, I know :rolleyes:) so I'm going to look at making it possible to use a pair of screws at each end. That will need provision of some plastic blocks under some seats as the body only has filled in under-seat voids at the centre...

Whilst elsewhere, learning about siting of compensation beam pivots for the C12, proportional loading of axles and so forth, continues... 

Edited October 24th: ha - always check all the kit contents before making substitutions! Whilst assembling the parts for the underframe, I found a separate printed plastic piece with three extra roof vents in a small bag with other unrelated parts - different material but identical profile. Never mind - the ones I used are to my eye a little closer to those shown in Nick Campling's Historic Carriage Drawings Vol 1, being rather smaller in relation to the other roof fittings, so no harm done :rolleyes:.

Edited by Chas Levin
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Underframe details in place:

2013770455_MousaGNRD12920201025(1).jpg.f9bb02cfb9db3e11ac7c964d58309d6f.jpg

 

The instructions suggest making sure the step supports are glued at the back as the steps are fragile (as it's noted they were on the prototype) but they don't seem that much more fragile to me than similar etched brass coach steps, though I realise these would break where brass will just bend (at any rate once or twice...).

I didn't spend time worrying about the striations and remains of pips under the steps, as they won't be seen in running use.

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More progress this week on the C12 - here are the frames with the trailing wheels' axle guide openings cleared, compensation beams holes drilled (the rear one is just in case I change my mind about the trailing wheel arrangements, or it may be used for a support to anchor a guide spring for the radial truck) and with the perforations around the rear fixed driving axle hole filled in (I know plenty of people leave these perforations clear but I thought I might as well fill in the gaps for added solidity!):

 

1031540244_LRMC1220201025(1).jpg.be2ec7fc9b68ea22bd22073dd2453600.jpg

 

A couple of days later and the frames are up:

 

1735537675_LRMC1220201028(5).jpg.efaf3600c6e038747999685f11743313.jpg

 

I've decided to go with the radial truck for the trailing wheels. I know it's totally un-prototypical but it'll be invisible unless you look underneath and with the taper I've introduced to the rear frame ends it allows some pretty tight curves:). You can also see the radial truck guides in place at the rear, very handy little LRM etch - here's a pic of the etch as it comes, next one made up with test wheels inserted:

 

1785734400_LRMC1220201031(1)LRMRadialtruck.jpg.982e202ddcdec3b247ad8c779f884b28.jpg

 

I based my calculations of the taper required on Jol Wilkinson's discussions on another thread about using the LRM radial truck on an LNWR 2-4-2 'Mansion House', along with running some tests with the frames taped and blu-tak'd together - a delicate operation but achievable with care:senile:. Like the radial truck, while the taper is un-prototypical it won't be visible in normal running. I went for a double bend, in for the track guides (to 1.2mm at their C/L) and then out again, returning to the line of the main part of the frames, to minimise the visible narrowing when the loco is viewed from the rear, with the rear frame spacer filed down to fit the new profile.

Finally, the frames with the horn guide opening removed on one side only (the bearing you see on the left is the opposite one, seen through the cleared opening of the frame nearest the camera) and a view of it on the jig, showing how this order of assembly will allow the first flexichas bearing to be fixed accurately:

 

214005190_LRMC1220201030(2).jpg.35b3447ecf58fb383588ea60fd683cae.jpg

 

1836734030_LRMC1220201030(4).jpg.80c014987adec7067b0a8ecce5eeefc0.jpg

Edited by Chas Levin
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I'm finally at the hornblock stage :D. In the course of getting here, I became very curious about the different systems on offer and how they compared: which manufacturers' bearings have flared grooves (which I learnt was an interesting part of Mike Sharman's original FlexiChas spec); which ones allow dropping out of the bearings and axles; can parts be interchanged between different manufacturers - bearings with flared grooves used with another maker's hornguides, for instance? It got quite confusing, trying to juggle all the data in my head, so I made an Excel sheet, to be able to see at a glance which makers' systems include a particular feature. I'm not sure if it will be of use to anyone else, but in case it is I thought I'd post it here:

 

 

2012320475_Hornblockcomparison20201101-2.jpg.4381d58b93859433dc9df211eb63cad3.jpg

 

And here's the original Excel sheet, in case anyone wants to use it themselves and add or edit things: 

Hornblock comparison 20201101-2.xlsx

 

The only ones I haven't yet obtained and measured are the High Level Kits Miniblox, though if anyone knows of any other types I've left out please let me know. They all have individual points of interest and my intention is to build at least one loco using each type... I wonder how long that will take me? :rolleyes:

 

 

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Chas,

the instructions for the LRM CSB/spring etched adaptors is attached, as it may be useful. The etched adaptors, shown in the second pdf file,  are designed to fit LRM hornblocks but I believe will also fit the High Level variety.

 

These were designed in the early days of CSBs.  Now, the adjustable mounts would probably be omitted and replaced by a bigger selection of the "fixed" mountings. The idea behind the different types was to give a degree of flexibility for CSB spring wire locations and sizes. Being soldered to the frames they could also be "moved" if required, something less easy with the handrail knob type located in pre-drilled holes.

 

I have to admit I haven't built any locos with CSBs but have used the "sprung" options, mainly for tenders.

 

Jol

Hornblock spring adaptor dwgs.pdf Hblox CSB adaptor.pdf

Edited by Jol Wilkinson
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52 minutes ago, Jol Wilkinson said:

Chas,

the instructions for the LRM CSB/spring etched adaptors is attached, as it may be useful. The etched adaptors, shown in the second pdf file,  are designed to fit LRM hornblocks but I believe will also fit the High Level variety.

 

These were designed in the early days of CSBs.  Now, the adjustable mounts would probably be omitted and replaced by a bigger selection of the "fixed" mountings. The idea behind the different types was to give a degree of flexibility for CSB spring wire locations and sizes. Being soldered to the frames they could also be "moved" if required, something less easy with the handrail knob type located in pre-drilled holes.

 

I have to admit I haven't built any locos with CSBs but have used the "sprung" options, mainly for tenders.

 

Jol

Hornblock spring adaptor dwgs.pdf 51.94 kB · 0 downloads Hblox CSB adaptor.pdf 31.18 kB · 0 downloads

 

Thanks Jol; I had the main Instructions sheet (John supplies it with the parts) but the second sheet with the etch I didn't have and the notes on which parts are which give added clarity. I've also now edited and re-posted my chart to include LRM's 14BA bolt option for adjustable mounting - I don't know how I came to omit that option, because the ability to adjust springing in that way was one of the things I had particularly looked for in the different systems! More haste, less speed:rolleyes:.

 

I'm surprised that you say the adjustable mounts would probably be omitted. I know I haven't yet actually tried building using them yet, but the idea of continuous adjustment using bolts seems to me to be a very useful option (which is why I'd particularly noticed it: Kean/Maygib, Gibson and LRM are the only systems that offer it). What happens if you need to adjust one axle relative to the others - in order to achieve a level footplate - to a height that lies between two fixed mounting points?

 

I'll have a look at interchanging the LRM and HLK hornblocks: by my measurement (using good quality digital calipers but still of course subject to the usual human error) the grooves in the HLK are fractionally narrower (0.1mm) than the LRM, which I thought might make for a slightly tighter movement.

 

As this loco's going to be simple compensation only, I'm probably going to keep both the LRM and HLK systems in reserve for when I build a CSB one, where I can properly try out the whole system; it seems counter-intuitive to use only parts of them as a first attempt. So, I'm currently making up and trying out the MJT FlexiChas etched guides, of which more later...

Edited by Chas Levin
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Chas,

the only reason why I thought the "adjustable" mounts might be omitted to make space for the fixed type is that, AFAIK, there has been no feedback on their use - good or bad. As they need careful assembly, I wonder if anyone has ever used them.

Jol

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