Wright writes.....

[thegreenhowards]

I shall now wade into the Kirk/ layout coach debate.

 

From my POV, I always took layout coaches to be a slightly less detailed/ less accurate than a perfect museum piece model but , on the upside, one that would run well as part of a long train and on which any lack of detail would not be readily noticeable in use. So, both a compliment on the running and an acceptance of slightly reduced to reflect its intended use and possibly the need to build a lot of them to resource a large layout. I’m firmly of the life is too short point of view and I’m ready to make compromises in order to resource my layouts in a reasonable amount of time. If that’s being lazy, then so be it. But I think of it as pragmatic.

 

As such, I like Kirk kits. They are quick and easy to build, there’s a wide range of diagrams and they're east to cut and shut. I do try to improve mine with MJT underpinnings and those brake thingamebobs on the roof, but that’s about as far as it goes. I actually find they work well as replacement sides for the newer Hornby Gresleys. This takes the best of both - the roof and underframe from the Hornby and the sides from the Kirk (although the benefit here is mainly the range of diagrams rather than the finesse). Four example this D.95 sleeper third was built from Kirk sides on a Hornby coach.

 

 

I also find the Kirks easy to cut and shut. This D.157 66’6” SLF was made from two Kirk 61’6” SLFs cut and shut together. I seem to remember this has a Kirk underframe with MJT white metal bits and MJT roof.

 

 

All this is not to decry etched brass kits. They clearly produce a better model…but it takes a lot longer.

 

Andy

[MJI]

Layout stock, i have lots, my version is as follows.

 

Correct vehicle type, buffers, bogies, livery, underframe bits, flush glazed if possible, correct numbers.

 

Not concerned by all the brake rigging, will have visible on wagons, but not on carriages.

 

Interior correct layout and basic colours.

 

Aiming for similar standards.

[Chuffer Davies]

Oh dear here we go again!  The compensation versus rigid debate.  We will never agree but it is a fact that there are many experienced modellers who do compensate or spring their models and believe there are definite benefits in doing so.

 

Sadly, unlike other discussions on this thread promoting better ways to build rolling stock and scenic modelling, as soon as there is any discussions around how to use advanced techniques for loco chassis construction these are instantly criticised as a waste of time.  They are clearly not a waste of time otherwise other similarly experienced modellers who contribute to this thread wouldn't themselves bother with it.

 

Can we therefore stop trying to impose our own personal preferences on those modellers who have yet to make up their minds and accept that rigid and non-rigid are just alternate approaches to chassis construction.  Both approaches can be readily made to work successfully once the modeller has taken the effort to develop the requisite knowledge and skills so to do.

 

I will continue to provide advice and guidance to those modellers that are interested in extending their skills beyond rigid chassis construction where ever and whenever the need presents itself.  Some may find these advanced techniques a step too far and revert to rigid chassis construction.  Others will take to it like a duck to water and will never build a rigid chassis, or install physical pickups, again.

 

Frank

[96701]

2 hours ago, Tony Wright said:

Good evening Alan,

 

I've given up using the Poppy's Woodtech jig. Not because it doesn't work - it does, but the end result is no better than by my using my ancient Jamieson chassis jig; which is much quicker. 

 

What I do is make the outer bearings (on a six-coupled) a nice fit in their frame holes, and apply the iron from the top. I then enlarge the centre hole a tiny bit, then apply the iron to the bottom of the bearings, effectively shoving that bearing upwards. I then fix the frames in the jig, solder all the spacers in place, and then remove the jig. I then ream all the bearings out using a one eight taper reamer (not a parallel one), and test-fit the wheels. There's never any rock.

 

Regards,

 

Tony. 

I seem to recall that Geoff Brewin told me that he designed the middle axle centre a few microns higher than the outer axle centres on a 6 coupled chassis.

[Bucoops]

The LRM N1 kit certainly has the centre axle slightly higher than the outers. I believe that's a Paul Craig design.

[lezz01]

So I've been thinking about the way you guys build rigid chassis and how to stop 6 coupled loco rocking on the centre axle without having the middle wheels off the track. If you do it by raising the middle wheels you have effectively built an 0-4-0 ignoring the leading and trailing wheels.

Now I haven't tried it because I don't build rigid chassis but I'm pretty sure that this will work or at least work better than having the middle wheels off the rail.

You will need the following items.

1, a length of straight track a little longer than the coupled wheelbase.

2, a piece of 9-12mm ply a little longer and a little wider than the length of track.

3, 2 elastic bands long enough to hold the chassis with it's wheels firmly to the track.

4, a tapered reamer or cutting broach.

Method.

First build the chassis using whatever jig you favour fixing only the outer axle bushes.

then open out the holes of the centre axle bushes so that the bushes are a sloppy fit in the holes but not so big that the flange on the bushes go through the holes in the frame with the reamer/broach.

Now fit the outer two sets of wheels and fit the centre axle bushes into the enlarged holes and insert the axle through the lose bushes and fit the wheels packing them out with enough washers so that there is as little side play as possible but you can still move the axle bushes around in the enlarged holes. 

Fit the coupling rods and fix in place with a bit of wire insulation so that they stay put. This will keep the middle wheels in line and stop them twisting out of true.

Now put the chassis on the rails and hold it in place with the elastic bands around the chassis and the length of wood as close to the outer wheels as you can. You just want to hold the chassis in place not clamp it rigidly to the track. Now press down on the middle of the centre axle with one finger applying as little pressure as necessary to ensure that both centre wheels are in firm contact with both rails. Now flux and solder the axle bush furthest away from you to the frame. Turn the whole thing around and repeat, and that's it job done.

Now you should have a rigid chassis with all six driving wheels resting equally on the track and thus having a proper 6 coupled chassis.

It should work just as well with 8 and 10 coupled wheels as well as long as you start out with the four outer wheels sitting square on the track to start with and the two or three inner axles floating slightly and work from out to in towards the middle. 

It's the best I could come up with that anyone can do without having to do anything more complicated than fix a bit of track to a bit of wood. The fact that rigid chassis builders are happy to have the centre wheels whizzing around doing nothing makes my teeth itch for some reason. Sorry but it's the inner engineer coming out I guess. Feel free to give it a go guys there's no charge but let me know how it goes please.

Regards Lez.     

[Michael Edge]

Sounds rather complicated but assuming this is a steam loco there is a snag in all this reasoning. The plate frames we build now have very little torsional stiffness compared with the boiler since you bolt it together the frames will be pulled out if true anyway. It’s much more important to make sure that the loco body is true, usually by reference to the lower edges of the buffer beams or drag beam. This didn’t apply so much in the old days of 1/16 in plate frames and definitely not with the solid brass block ones discussed a while back.

[rodent279]

3 hours ago, lezz01 said:

So I've been thinking about the way you guys build rigid chassis and how to stop 6 coupled loco rocking on the centre axle without having the middle wheels off the track. If you do it by raising the middle wheels you have effectively built an 0-4-0 ignoring the leading and trailing wheels.

Now I haven't tried it because I don't build rigid chassis but I'm pretty sure that this will work or at least work better than having the middle wheels off the rail.

You will need the following items.

1, a length of straight track a little longer than the coupled wheelbase.

2, a piece of 9-12mm ply a little longer and a little wider than the length of track.

3, 2 elastic bands long enough to hold the chassis with it's wheels firmly to the track.

4, a tapered reamer or cutting broach.

Method.

First build the chassis using whatever jig you favour fixing only the outer axle bushes.

then open out the holes of the centre axle bushes so that the bushes are a sloppy fit in the holes but not so big that the flange on the bushes go through the holes in the frame with the reamer/broach.

Now fit the outer two sets of wheels and fit the centre axle bushes into the enlarged holes and insert the axle through the lose bushes and fit the wheels packing them out with enough washers so that there is as little side play as possible but you can still move the axle bushes around in the enlarged holes. 

Fit the coupling rods and fix in place with a bit of wire insulation so that they stay put. This will keep the middle wheels in line and stop them twisting out of true.

Now put the chassis on the rails and hold it in place with the elastic bands around the chassis and the length of wood as close to the outer wheels as you can. You just want to hold the chassis in place not clamp it rigidly to the track. Now press down on the middle of the centre axle with one finger applying as little pressure as necessary to ensure that both centre wheels are in firm contact with both rails. Now flux and solder the axle bush furthest away from you to the frame. Turn the whole thing around and repeat, and that's it job done.

Now you should have a rigid chassis with all six driving wheels resting equally on the track and thus having a proper 6 coupled chassis.

It should work just as well with 8 and 10 coupled wheels as well as long as you start out with the four outer wheels sitting square on the track to start with and the two or three inner axles floating slightly and work from out to in towards the middle. 

It's the best I could come up with that anyone can do without having to do anything more complicated than fix a bit of track to a bit of wood. The fact that rigid chassis builders are happy to have the centre wheels whizzing around doing nothing makes my teeth itch for some reason. Sorry but it's the inner engineer coming out I guess. Feel free to give it a go guys there's no charge but let me know how it goes please.

Regards Lez.     

Does all this effort to achieve a perfectly square chassis & wheelsets not fly out of the window as soon as your perfectly square chassis hits a section of less than perfectly square p-way?

[Dunsignalling]

21 minutes ago, rodent279 said:

Does all this effort to achieve a perfectly square chassis & wheelsets not fly out of the window as soon as your perfectly square chassis hits a section of less than perfectly square p-way?

 

Not necessarily, so long as you make it heavy enough...😇

 

[chris p bacon]

8 hours ago, Bucoops said:

The LRM N1 kit certainly has the centre axle slightly higher than the outers. I believe that's a Paul Craig design.

IIRC it isn't a Paul Craig kit, but the name escapes me at present of who it actually was (Steve Barnfield??)

Edited April 17, 2023 by chris p bacon

[Bucoops]

31 minutes ago, chris p bacon said:

IIRC it isn't a Paul Craig kit, but the name escapes me at present of who it actually was (Steve Barnfield??)

 

It has a name on the etch, will check when I get home.

[Tony Teague]

11 hours ago, Chuffer Davies said:

Can we therefore stop trying to impose our own personal preferences on those modellers who have yet to make up their minds and accept that rigid and non-rigid are just alternate approaches to chassis construction.  Both approaches can be readily made to work successfully once the modeller has taken the effort to develop the requisite knowledge and skills so to do.

 

I have no opinion on this whatever, but surely one has to recognise that this is TW's thread and that he is therefore entitled to give weight to his preferred approaches - as you are on your thread?

 

[t-b-g]

There are many factors that impact on whether all the wheels on a loco are touching the rails. You have, at least you should have, rails that are not sitting vertically but are inclined inwards at 1 in 20 or thereabouts. You have wheels that are rarely 100% true. You have a coned wheel tread rather than a flat one. You have a small amount of play in bearings on kit built or scratchbuilt models and often wheels with lots of play on RTR models.

 

Many models have a small degree of "floppychas" through wear and tear despite being supposedly built rigid, especially after lots of running.

 

Those who advocate compensation or springing as a way of keeping all the wheels on the track are quite correct in that it is the only route to ensure that all your wheels are in good contact with your track all the time but many examples I have seen are over the top in terms of the amount of movement provided and the complexity.

 

My personal experience, in 00 and EM, is that I can get running as good as I could wish for with rigid mechanisms and that I can also have brake blocks and standpipes etc. a bit closer to wheels that can't move up and down. I also find it easier to get a mechanism running smoother when the distance between your crankpins doesn't change as a wheel goes up and down relative to its neighbour. I find them easier to test on a bench too, if the wheels can't move about in relation to each other. Turning a sprung or compensated loco upside down and running it with wires to the motor doesn't give a good idea of how it will perform on a layout.

 

I have never moved the centre axle upwards on 6 coupled locos. If your baseboards and track are like ski jumps, then you should build your locos compensated or sprung. I find that with decent flat track and baseboards, any rocking on the centre wheel is undetectable.

 

I have tried compensation, springing, a combination of the two plus just having the centre axle able to move up and down a bit on springs with the front and back axles rigid. When running my layouts, I cannot detect any difference between the types of mechanism.

 

So while I can appreciate and accept that springing or compensating has benefits and I admire and respect those who build them that way and get them to run superbly, I don't go down that route having considered and tried various options.

 

Which is why no lesser person than the late, great, Iain Rice once wrote to MRJ describing me as "the worst Luddite since Tony Wright".

Edited April 17, 2023 by t-b-g
Spelling

[Tony Wright]

I think debate (on any subject) is healthy. If it's about rigid frames or sprung/compensated frames, then so be it.

 

My recent comments have been in response to questions posed by those starting on their 'modelling journey' so to speak. And, I can only speak with 'confidence' from my own experience, having built (what must be approaching 600) locos, most of which have rigid frames; those I've built with compensation show no improvement in running (am I not doing it correctly?). 

 

My own conclusions are these.....

 

Any chassis must be erected squarely on a jig (the fact that the centre wheels on a six-coupled chassis are slightly higher is a bonus because it prevents any see-sawing, and, once the rods are on, they're doing just as much work as any of the others).

 

There must be sufficient pick-ups - on the tenders as well, if necessary.

 

Any space inside bodies be stuffed with ballast (no room then for decoders).  

 

Trackwork must be well-made/well-laid, and any dead-frog points be banished forever.

 

Having been called the greatest model railway Luddite (a great compliment) by the late Iain Rice, I will continue to describe the way I build locos. This is not to suggest I try to mislead newcomers/the inexperienced by taking them down 'old-fashioned' routes, but merely to show them a system which 'works'. A system which produces powerful, fast, free-running and reliable steam-outline locos. Not only that, but (smaller) locos as well which will crawl without jerking, juddering, stuttering and derailing. 

 

If others wish to follow a more-sophisticated path (and describe that route), then I'll be delighted if they show their work on Wws. One thing which must be stated, however (at least in my view), is that compensation/springing is more-complicated and takes considerably longer. There's also the greater skill-factor necessary as well, something those with that requisite level don't always seem to acknowledge. 

 

At one Missenden, years ago, the late, great Mike Sharman was showing 'students' how to build 'Flexi-chassis' in his room. I was showing my charges how to build rigid chassis in mine. In less than a morning, one of my 'students' had built his chassis (an inside-cylinder 0-6-0), and it ran beautifully-smoothly on the test track (which included a point and reverse curves). It was the next day before the compensated equivalent chassis was running. On the test track, there was no discernible difference in performance. However, the rigid chassis performed dismally on Mike's 'obstacle course' of a test track; it consisting of dodgy joints, twisted alignment and irregular curves. A triumph for the compensated chassis? Yes, but if model railway track were laid as badly as that 'fairground' test track, then I'd suggest he/she who laid it give up railway modelling!  

[MikeTrice]

8 minutes ago, Tony Wright said:

However, the rigid chassis performed dismally on Mike's 'obstacle course' of a test track; it consisting of dodgy joints, twisted alignment and irregular curves.

Reminds me of the train scene in Our Hospitality with Buster Keaton:

 

[gr.king]

I've built locos and stock with full compensation (yes, for OO), some with a half-way arrangement, some with a certain amount of springing, some rigid. My view is that the choice is influenced by the type of loco or stock being built (or modified), the wheels that will be used, the kind of track on which it will be expected to run, and the standard to which it will be expected to run (and pull). Similar considerations apply to the number of pick-ups I fit to a loco (and tender). If there's a limit to the available construction time that has some influence too. There's no universal right or universal wrong, and no eleventh commandment to decide the matter. It's another case of something that depends on what it is desired to achieve.

Edited April 17, 2023 by gr.king
Tidying up grammar!

[31A]

I quite often make the middle axle sprung, with a view to improving current collection.  My track (Peco) isn't bad but I can't claim that it is mirror-like.

 

These are the Comet frames for a J39.

 

 

Ordinarily I wouldn't bother to spring the middle axle for a tender engine, as I would fit pick ups on both the loco and tender of a tender engine, but in this case I wanted to try out the 'American' system of current collection.  The middle axle bearing holes are slotted out to give about 1-2mm of vertical play above and below the horizontal centre line.  The middle bearings are held in place by a large washer soldered over the inside (carefully not soldering the whole lot to the frames).  This washer has a flat filed on one side and a straight piece of etch scrap soldered to the frame, stops it rotating.  The spring is a piece of phosphor bronze wire running between brackets made from scraps of FB rail.  I did fit extra, tapped spacers between the axles in case I wanted to add wiping pickups later, but this has not been necessary - the running is very good without them (the middle axle of the tender has similar vertical play).

 

It's a pity more RTR locos don't have a sprung axle as it is a great aid to reliable running; Bachmann fitted them to several of their early models but seem to have stopped doing so quite a while ago.  The Oxford Rail N7 has a sprung leading axle, and is a very reliable performer.  If it's a case of cost, I'd rather have a sprung axle than sprung buffers!

 

[Jol Wilkinson]

3 hours ago, Michael Edge said:

Sounds rather complicated but assuming this is a steam loco there is a snag in all this reasoning. The plate frames we build now have very little torsional stiffness compared with the boiler since you bolt it together the frames will be pulled out if true anyway. It’s much more important to make sure that the loco body is true, usually by reference to the lower edges of the buffer beams or drag beam. This didn’t apply so much in the old days of 1/16 in plate frames and definitely not with the solid brass block ones discussed a while back.

If you fix the chassis to the body rigidly at one end and leave the other end "slack" it overcomes the problem with the body distorting the chassis. There are several ways of doing this, a bolt through a top hat style bush with built in clearance being one. Another way, which I have built into several kit designs is for the front coupling hook to pass through the buffer beam and two aligned slots in the front frame spacer. That retains the body but doesn't clamp it tightly.

 

I found chassis distortion a problem when I were nobbut a lad and built OO locos with rigid chassis. An otherwise well running chassis would fail to run properly when fixed to the body. Since I started building compensated/sprung chassis I have had no problems, probably because a small amount of twist doesn't lock things up.

 

While as many pickups as possible is a good thing, I have one compensated chassis 4-4-2T with pickups on the driving wheels only. It will run over an exhibition weekend without any problems. 

Edited April 17, 2023 by Jol Wilkinson

[Bucoops]

11 minutes ago, Jol Wilkinson said:

If you fix the chassis to the body rigidly at one end and leave the other end "slack" it overcomes the problem with the body distorting the chassis. There are several ways of doing this, a bolt through a top hat style bush with built in clearance being one. Another way, which I have built into several kit designs is for the front coupling hook to pass through the buffer beam and two aligned slots in the front frame spacer. That retains the body but doesn't clamp it tightly.

 

I found chassis distortion a problem when I were nobbut a lad and built OO locos with rigid chassis. An otherwise well running chassis would fail to run properly when fixed to the body. Since I started building compensated/sprung chassis I have had no problems, probably because a small amount of twist doesn't lock things up.

 

While as many pickups as possible is a good thing, I have one compensated chassis 4-4-2T with pickups on the driving wheels only. It will run over an exhibition weekend without any problems. 

 

I've seen you and others mention this before. I'm slowly approaching the point where I am ready to do this - but one thing that crosses my mind is if the body is a little loose at one end, would it not have a tendency to rattle?

[BMS]

Sharman's Wheel book.

As Sharmans book is currently in the 4th edition (S4 Society), have the errors mentioned previously been corrected, please?

[Barry Ten]

55 minutes ago, Bucoops said:

 

I've seen you and others mention this before. I'm slowly approaching the point where I am ready to do this - but one thing that crosses my mind is if the body is a little loose at one end, would it not have a tendency to rattle?

 

Not in practise. It can be retained quite snugly at the "sloppy" end but still have a margin of error for the chassis not to be distorted.

[Barclay]

Always glad to see the Great Compensation Debate rear its head again - the gift that keeps on giving !

 

In many ways of course it's horses for courses and in 00 and EM I see that it is not entirely necessary for a fast running tender engine on good smooth track, but try doing this and you will see what all the fuss is about !

 

 

 

 

 

 

 

 

[60526]

On 15/04/2023 at 13:03, Tony Wright said:

The O4/8 is now almost complete. Just brakes (to source), rear sandboxes (to source) and balance weights (to cut from Plastikard), and it should be there.....

 

 

I used the Bachmann B1's backhead and cab interior, hacked about to suit. Yes, the splashers over the rear driving wheels are still present, but these won't really be seen behind a crew.

 

 

Truly old fashioned frames, but an excellent runner. 

 

Any 'scabby' bits should disappear under painting/weathering.

 

 

 

Final layout-testing this morning proved itself entirely capable of handing over 40 loaded minerals (all the spare space in the boiler is filled with 'Liquid Gravity'). 

 

This is definitely a 'layout loco', but, I hope captures the 'look' of an O4/8. It's definitely a 'budget' loco, too. 

 

The basic K's kit I bought for £20.00. It had been started (not very well, but fortunately glued-together), had some bits missing and came with no instructions (so what?). I obtained the Portescap in a 'gummed-up' condition, inside a partly-built GEM MR 4-4-0 (total cost, £40.00). I un-gummed the Portescap, and sold the loco body and tender for £20.00, including the wheels (old Romfords). Obviously, the loco wheels for the O4/8 were new (Markits), but the tender wheels (old Jacksons) were in the K's kit. The Bachmann B1 body was give to me (as were two others), so there was no cost there (thanks again Graeme, Graham and Andy). Even so, I don't think Bachmann B1 bodies are that expensive, even new. Other bits? Buffers and brass/nickel silver sheet came from stock, and there were just a few handrail pillars and wire to complete. Graham King's donation of the chimney and dome also helped considerably, so, thanks to him again. Other than the loco's wheels then, a pretty cheap loco? 

 

Ebay had nothing to do with this, of course. I obtained the bits from collections or at shows; you just have to look beyond the second-hand RTR! 

 

It's certainly superior to............

 

 

My original 45 years old O4/8, made from a mixture of K's, Jamieson and scratch-building.

 

But inferior to............

 

 

This Little Engines O4/8 (builder/painter unknown). This came from the estate of a deceased modeller, but didn't run very well. I made it run properly, and it's now the property of Sandra Orpen (and will be re-gauged for use on Retford).

 

Why did I not retain the best O4/8 of the three? Because I didn't build it myself! 

 

 

Any idea who sells the oval brass buffers?

[Izzy]

Having built chassis with some measure of axle movement for over 50 years, and just recently made my first rigid chassis in more than 30 years for a particular loco, I think that the advice for a newcomer to building chassis to start off with a rigid one is sound. Yes, move on to whatever takes your fancy later if you find the need, but learn the basics first. How to get a simple running chassis. I would guess most of us started off this way, I certainly did, and then progressed as required.

 

TBH my view is that the most important factor above all else seems hardly to be mentioned, weight. Whatever you make, however you do it, this aspect is the single biggest factor for both good & reliable electrical contact and track holding IMHO, far more than anything else, and especially when current collection through split-axles etc is involved. Past that it’s mostly about overcoming lack of weight in one way or another to ensure reliable contact. Very rarely  is it about track holding. Apart from P4 & S7 it isn’t needed (and then not always), the flange depths mostly being more than adequate even on quite roughly laid track.

 

With regard to electrical collection I have found the most reliable combination has been hard brass wire scrapers pressing on cast iron wheels running on nickel silver track. I think I have cleaned the wheels of one particular loco with this combination once in around 25 years. 
 

Bob

Edited April 17, 2023 by Izzy

[Tony Wright]

32 minutes ago, 60526 said:

Any idea who sells the oval brass buffers?

I cannot remember Charlie,

 

The 'persistent' modeller collects masses of spares, including buffers. 

 

When one of our Wolverhampton model railway shops closed down, I bought trays full of bits and pieces from the proprietor's counter; these included several varieties of buffers.

 

Often when I'm 'disposing' of collections, there'll be those plastic tray-things, which slide in and out of plastic 'cases'. Sorting through these can be a real 'thief of time', at times a commodity I don't have too much of. However, they'll often contain any manner of spares, though don't always believe what's written on any scraps of paper.

 

In the case of the O4/8, the front buffers were solid brass turnings, but from where? And, made by whom? I have no idea!

 

They're not that common, certainly not with fat shanks, though oval-headed buffers are readily-available for the likes of Mk.1 carriages, Pullman cars or Bulleid stock. The problem is that they're shanks are thin, and not suitable for locos. Comet produces an oval loco buffer, but (from memory) it's got a step on top of it (not suitable for ex-GC 2-8-0s). 

 

 

What I did with regard to this very, very old scratch-built O1 was to source some fat-shanked buffers (with round heads), cut off the oval heads of some thin-shanked buffers, then soldered these to the round heads (replicating several prototypes which have this feature). They're not sprung (a waste of time in my opinion), which means they don't rotate into weird positions. 

 

Other than that, I don't know. Do those who cater for diesel-/electric-outline modellers provide oval buffers? K's certainly didn't with their O4 kits, though Little Engines did with theirs.

 

Regards,

 

Tony.