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Johnster's 44xx


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1 hour ago, Craigw said:

With all this talk of the 44XX, it is time for a photo. This is a scan of a negative I won via Ebay. Please do not post it anywhere else with out my permission. With the lack of the cab sliding shutters, portholes above firebox and the taller vacuum pipe I am suspecting early 1920s. I am not sure of the location so suggestions welcome. 

 

As one who is used to the proportions of locos with smaller wheels, I find that the 44 looks more balanced to me.

 

Must be an Australian thing!

 

Regards,

 

Craig W

img428.jpg

 

Good broadside on shot for detail and measuring; thanks Craigw.  Loco aesthetics and the impressions they make on us are personal taste of course, but I wonder if you are familiar with the Hawthorn, Leslie (RSH by then) 2-6-2T locos built in the early 50s for a NSW colliery line, can't recall which one now, to a design originally for the Newport Alexandra Dock & Railway Company half a century before.  These were to my mind handsome and well proportioned machines, very similar in leading dimensions to 45xx.  One of the N,AD&R locos survived until the early 50s as shed pilot at Canton, withdrawn as the new ones for NSW were being built.

 

To my way of thinking, the 45xx looks like a 'modern' GW loco, especially in later form with blanked off portholes, top feed, and bunker extension.  The 44xx, pretty much the same thing despite the subtle differences apart from the wheels, even in the later form, comes across as archaic and anachronistic, almost from a different and earlier period of design, although in reality the one class followed directly in production from the other.  This is entirely because to the smaller wheels and the open feel of the spokes, and the bareness of the area below the running plate; it looks more sort of primitive.  It was, of course, pretty cutting egde in 1906.  This 'antique' look might explain some of the charm.

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3 hours ago, The Johnster said:

 

Presumably the result of 'reversing' the axle spacing for the 45xx.  The tank looks to be in the same place on both locos in fore and aft terms, with the top of the motion bracket bolted to the front of it, but the leading wheel axle centre positon is moved backwards a smidge on the 45xx cf. the 44xx.

Having lined up sketches in different ways, If you line up the driving wheels then the cylinders, boiler and cab also line up, but the rest of the wheels  have moved. The other two driving wheels have moved back 6 inches, the front buffer beam and leading pony wheel back 2 inches and the trailing pony wheel back 6 inches. The rear buffer beam, of course, was something of a moveable feast anyway.

I think the 4'1.5/4'7.5 wheels is interesting, because the 4'1.5 wheels were well established for branch etc with the 850/1901/2021 classes as against 4'7.5 on the larger 0-6-0Ts. You'd think they would have known what the limitations were. I wonder if there was something of a speeding up of trains? 

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Not to mention the even smaller driving wheels of Railmotors, popular at around this time.  Many branch timetable timings never changed much from their original opening, but main line running times were increasing rapidly in the early 1900s and quite a few of the duties for the new small prairies involved some main line stopping work, where smaller wheels are an advantage for accelleration but limit comfortable running speed, which may have been a factor.

 

The 4'7" wheels of the bigger 0-6-0 tanks were for short haul heavy freight work, though they were certainly used for passenger work as well.  Passenger tank engine driving wheels had stabilised at the 5'2" mark with the Metros and 517s in Dean's time, and Churchward did not design any loco in that wheel size.  Not sure if any conclusions can be drawn from this bar that the 4'1" wheels of the 850/1901/2021 worked well enough on branch passenger jobs, but not well enough on small prairies to justify more than their use on only the first 11 of what evenutally totalled 186 engines. 

 

It may be that the new engines were expected to work longer distances on longer branch routes that had previously been the preserve of small tender locos; the Cardigan Branch comes to mind but remember the small prairies did the passenger work on the Ebbw Vale line as well..  4'1" wheels are a bad idea here, fine for the climbs over the Presceli Mountains  or the slog up to Cwm from Aberbeeg, but it's a long way to go that takes a long time to get there if you can't manage more than about 25mph, and you use a lot of steam, and consequently water, consequently coal (which will attract the attention of the bean counters who run things), for the distance covered.  Didn't drivers get a bonus for low coal consumption?  4'7" is much better.

 

But, clearly, I will do better with this project if I retain as much of the structure of the Keyser kit as possible.  It's hardly fine scale modelling, and looks appalling crude beside a Mitchell kit, but Keyser seem to have been pretty good in terms of scale measurements of body parts; it is the thickness and crudity of the whitemetal castings that let these kits down.  Retaining the Keyser chassis is clearly becoming more important the more I plan the rebuild, and current thinking is not to use much more than the cylinders, slide bars, motion brakcets, and motion from the Bachmann engine, perhaps the pony and trailing trucks as well.  The model I've bought has nice turned brass buffers and good buffer beam detail.

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I can't quite explain why this topic has ended up in 'Prototype Questions'; it would be more at home in 'Modifying and Detailing RTR stock'.  No doubt one of my 'senior moments' is responsible, and I don't know how to move the topic over to Mod/Det, so I am going to open a new topic over there.  Obviously I need a new name for it to avoid confusion with this one, so please look for 'Tondu 44xx' over there; I'll crack on and set it up over the next few minutes!

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Which I did. honest, under the title of 'Tondu 44xx', but the mods have apparently not approved this.  Ok, to continue here for now...

 

... the loco has arrived, a day earlier than expected, and I have had a first look at it.  As per my plan, put the chassis on the rails and cranked up the power to check for shorts, of which there were none, but, to my considerable surprised, the chassis tried to run!  Not quite sure how, as there are no pickups or visible method of connecting the motor terminals to the wheels, so the thing is clearly built on a split chassis principle.  But there seems to be no isolation between the two halves of the chassis.  The axles run in plastic tubes, so clearly current is being prevented from what must be split axles inside the tubes from reaching anywhere it shouldn't, and the motor is fed on one. top, terminal by a wire soldered from the terminal to the rh chassis member and to the bottom one by simply being in contact with the lh one.  But the two main chassis members are held together by brass spacers soldered into position, and I cannot see how current is getting from the wheels to the chassis members or why/how they do not short out.

 

But, it lives (!), and with a bit of coaxing runs, and then with a bit of lubrication runs better,  and after an hour of back and forth is now a noisy but smooth performer!  Waggles it's tail a bit at top speed, about 30mph with the gearing (can't imagine the real ones were that steady at any sort of speed, and once under way is smooth enough with the big flywheel, but is not a reliable starter in either direction; maybe this will improve as it loosens itself up a bit.  Without the body attached, it is very tail heavy and I have fitted the cylinder assembly to alleviate this.  It is reverse polarity, and without dissassembling the whold chassis to get at the bottom motor terminal there is not much I can do about this, as even the motor retaining screw is hidden beneach the trailing axle.  I wasn't expecting it to run at all!

 

B2bs are fine and the loco is happy with my 30" minimum radius turnouts and insulfrogs.  Overrun from top speed with the flywheel is about 9".  Not sure of the value of the flywheel, and have a feeling this is the root of the reluctance to start.  It is happier starting in reverse, but starting is not reliable in either direction, and I have had to give the flywheel a push to get her going a few times, also smooth starting at low speeds is not ideal.  Fair play, this is an ancient kit and I can't expect performance equal to current RTR standards, and it is doing well despite the stiffness and is helped by very un-RTR gearing and the flywheel once it is on the move.

 

The general stiffness at starting is, I think, something that is borne out by the relatively high setting the controller needs to get her going, and I am of the view that the combination of this, the inertia of the flywheel, and the amount of noise the loco makes when it is running, and the buzz before she starts to move, are all indicators of a loco that runs despite itself because the motor is powerful enough to overcome the inertia.  I can't identify the motor, it's an open frame 5-pole with magnets at each end and very substantial main frames; it looks a bit of a thug!  The flywheel is very intrusive in the cab and the bright brass draws attention to it, another reason to get rid of it.  If I end up keeping it, I will paint it matt black to help hide it, but anything that moves like this is going to be pretty obvious...

 

But, should I decide to get rid of it, matters are not that simple because I cannot see how it is fixed to the drive shaft.  Forcing it off is asking for trouble and the so, I would say, is stripping the chassis down to see how to get at things, so a decision to dispose of it will mean cutting the shaft, which is a bit more irreversable than I'd like. 

 

Anyway, it's early doors for this sort of decision just yet.  Moving on to the bodyshell, it's all there, and the only immediate repairs are replacing one of the front buffer beam reinforcment bars (done) and re-attaching the cab steps; there are front steps as well but these are missing.  I'll be replacing the smokebox dart, rather feeble included in the smokebox door casting, and fitting lamp brackets.  Even if the flywheel is cut off, the motor will intrude into the cab (this is a model that is 'of it's time'), and my usual cheat of blocking the sightlines into the cab with crew will be resorted to.  I might have a go at cab rear bulkhead detail.  The chosen prototype is 4404 in early 1948 'tranition' livery, and I will be repainting her in green with Egyptian Serif lettering.  This loco did not have outside steam pipes at this time, and the model is in this condition.  The cab windows need glazing and the rear one need etched coal bars, and she needs a whistle, because it would be daft if just the driver whistled...

 

Apart from that I won't be doing much to the bodyshell.  There is already coal (and a bucket!) in the bunker and whoever built the kit has made a tidy job of the assembly, the joints are smooth and everything is straight and square, chimney and dome sat in well, central, and upright.  The main work is going to be the motion...

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Thoughts on the subject of why a flywheel might adversely affect performance...

 

This loco is very much the sort of thing I'd have built in the 70s, in the belief that the flywheel, split chassis current collection, and gearing would guarantee good running.  I have since revised my opinion on all three of those matters.  The aim of the game, for me, has always been good slow running, reliable feed of current to the motor, and smooth starts and stops.

 

Taking the last first, gearing.  Brought up in an age when RTR gearing was around 20:1 and slow running was next to impossible, I believed that higher gearing ratios would give me better performance in this respect.  Other things being equal, they did, but other things weren't always equal and there is no free lunch; the higher the gearing the more worm is in contact with the more cog, so friction is increased, and meshing becomes critical.  So there is a limit to the improvements that can be achieved through gearing alone, and my estimations of what were suitable ratios were far too high, even for the low speed BLTs I was involved with.  I now believe  that 30:1, which is ballpark what most current RTR steam outline has, is about right, though 35:1 would be better, and that the overall speed of the loco sould be determined by the size of the driving wheels, as it is in reality.  40:1 and above is counter productive, unless an integral gearbox is used to guarantee perfect meshing.  This model does not have a gearbox; the meshing depends on the angle of the motor as it sits in the frame.   It is ok in that it works, but my suspicion is that it is a little tight.

 

Next, split chassis current collection.  Influenced by the perfect running of fully compensated chassis with split pickup featured in 70s and 80s magazines, I became a fan of this.  It seemed very obvious to me that wiper pickups act as brakes on the wheels, preventing the free running that good slow performance and smooth starts and stops depends on, and that wipers needed fine adjustment (some still do) and picked up crud too easily.  The magazine articles featured handbuilt chassis with Portescap combined motor and gearbox drive (at 38:1); the best possible quality of components built by the most skilled and competent modellers.  When Mainline started producing what I thought was RTR as good as it was possible to achieve, with split pickup, I was delighted, but we all know what happened next and why; poor design and poor quality components scuppered the models and have done permanent harm to the split chassis idea, though some models still use forms of it.  Modern RTR runs very well despite the wiper pickups because of material that allows finer adjustment and motors powerful enough to overcome the friction.

 

Now, to the nub, flywheels, again a common feature of those perfect runners in the magazines.  A flywheel is bound to improve performance, isn't it?  It will carry your loco over a dead spot, and smooth the running, aiding smooth stops.   Well, yes, but I deluded myself that flywheels would make my slow running and smooth starting dreams come true, and they didn't.  Why not? 

 

Dunno. 

 

Ok, Johnster, think about it.  A flywheel will smooth out the running when the loco is in motion, obviously, and it is more effective in this respect the faster the loco is running.  When the loco is running slowly, as I keep insisting it must do, it is at it'd least effective, and when it comes to starting from rest it has no effect at all.  Even when you are coming to a stop, if you have let the speed decrease gradually, by the time you are running the final foot or so it has very little effect.

 

Moreover, when you are starting, not only does the fw have no effect whatsoever, it might be causing the motor to not run freely at it's lowest possible speed.  This would be for two reasons, firstly that a stationary fw is an inert mass (and who am I to claim any moral high ground over it on that score) that the motor has to make move, and therefore it needs more current to allow this to happen.  So, once the fw begins to move, the inertia and friction are overcome too quickly and the loco races away, the fw having now lost it's battle with voltage, and your smooth start is ruined.  Secondly, it seems to me that when the fw is at rest, it is a load that is bearing downwards on the motor shaft, possibly meaning that the shaft is not running true and that it is not held evenly by the bearing, which will force the shaft upward to press against the top of the other bearing.  This increases friction at the critical point at which the motor starts turning.

 

So, it is possible that too heavy a flywheel will inhibit the smooth starting performance of the loco, and It is my feeling that this might be the case with 4404 (actually 4406 at the moment, another Tondu denizen but I want 4404's livery).  It's a pretty big flywheel. 

 

Should I remove it or not?  As I said earlier, this would be an irreversible move, and the worst that could happen is that starting performance is not improved, while it is quite possible that in fact it will be.  To cut or not to cut, comments welcome!

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6 hours ago, The Johnster said:

Thoughts on the subject of why a flywheel might adversely affect performance...

 

This loco is very much the sort of thing I'd have built in the 70s, in the belief that the flywheel, split chassis current collection, and gearing would guarantee good running.  I have since revised my opinion on all three of those matters.  The aim of the game, for me, has always been good slow running, reliable feed of current to the motor, and smooth starts and stops.

 

Taking the last first, gearing.  Brought up in an age when RTR gearing was around 20:1 and slow running was next to impossible, I believed that higher gearing ratios would give me better performance in this respect.  Other things being equal, they did, but other things weren't always equal and there is no free lunch; the higher the gearing the more worm is in contact with the more cog, so friction is increased, and meshing becomes critical.  So there is a limit to the improvements that can be achieved through gearing alone, and my estimations of what were suitable ratios were far too high, even for the low speed BLTs I was involved with.  I now believe  that 30:1, which is ballpark what most current RTR steam outline has, is about right, though 35:1 would be better, and that the overall speed of the loco sould be determined by the size of the driving wheels, as it is in reality.  40:1 and above is counter productive, unless an integral gearbox is used to guarantee perfect meshing.  This model does not have a gearbox; the meshing depends on the angle of the motor as it sits in the frame.   It is ok in that it works, but my suspicion is that it is a little tight.

 

Next, split chassis current collection.  Influenced by the perfect running of fully compensated chassis with split pickup featured in 70s and 80s magazines, I became a fan of this.  It seemed very obvious to me that wiper pickups act as brakes on the wheels, preventing the free running that good slow performance and smooth starts and stops depends on, and that wipers needed fine adjustment (some still do) and picked up crud too easily.  The magazine articles featured handbuilt chassis with Portescap combined motor and gearbox drive (at 38:1); the best possible quality of components built by the most skilled and competent modellers.  When Mainline started producing what I thought was RTR as good as it was possible to achieve, with split pickup, I was delighted, but we all know what happened next and why; poor design and poor quality components scuppered the models and have done permanent harm to the split chassis idea, though some models still use forms of it.  Modern RTR runs very well despite the wiper pickups because of material that allows finer adjustment and motors powerful enough to overcome the friction.

 

Now, to the nub, flywheels, again a common feature of those perfect runners in the magazines.  A flywheel is bound to improve performance, isn't it?  It will carry your loco over a dead spot, and smooth the running, aiding smooth stops.   Well, yes, but I deluded myself that flywheels would make my slow running and smooth starting dreams come true, and they didn't.  Why not? 

 

Dunno. 

 

Ok, Johnster, think about it.  A flywheel will smooth out the running when the loco is in motion, obviously, and it is more effective in this respect the faster the loco is running.  When the loco is running slowly, as I keep insisting it must do, it is at it'd least effective, and when it comes to starting from rest it has no effect at all.  Even when you are coming to a stop, if you have let the speed decrease gradually, by the time you are running the final foot or so it has very little effect.

 

Moreover, when you are starting, not only does the fw have no effect whatsoever, it might be causing the motor to not run freely at it's lowest possible speed.  This would be for two reasons, firstly that a stationary fw is an inert mass (and who am I to claim any moral high ground over it on that score) that the motor has to make move, and therefore it needs more current to allow this to happen.  So, once the fw begins to move, the inertia and friction are overcome too quickly and the loco races away, the fw having now lost it's battle with voltage, and your smooth start is ruined.  Secondly, it seems to me that when the fw is at rest, it is a load that is bearing downwards on the motor shaft, possibly meaning that the shaft is not running true and that it is not held evenly by the bearing, which will force the shaft upward to press against the top of the other bearing.  This increases friction at the critical point at which the motor starts turning.

 

So, it is possible that too heavy a flywheel will inhibit the smooth starting performance of the loco, and It is my feeling that this might be the case with 4404 (actually 4406 at the moment, another Tondu denizen but I want 4404's livery).  It's a pretty big flywheel. 

 

Should I remove it or not?  As I said earlier, this would be an irreversible move, and the worst that could happen is that starting performance is not improved, while it is quite possible that in fact it will be.  To cut or not to cut, comments welcome!

A very thoughtful piece , Johnster .

My view ( for what it is worth) - modem motors and gearboxes are so good that the efficiency of pick ups determines how well the ensemble performs. It is the area I struggle with .

As to flywheels, I am in favour . My Bachman 56 xx has one and is a fine performer. I built an 0-4-4 with compensation, Mike Sharman gearbox and Mashima  motor  with a flywheel and that is another smooth performer . Pick ups BTW are Ypres.

Re To leave or to remove your flywheel. I favour leaving it…it may or may not improve matters but you can’t put it back .

Do you remember P.D. Hancock’s solution ? He inserted a pin into the worm drive so that the motor initially revolved under no load . Having overcome starting inertia and engaged the pin  , it then took up the drive thus smoothing out the start of the train .

Hope this helps .

Ken 

 

 

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5 hours ago, 1466 said:

My view ( for what it is worth) - modem motors and gearboxes are so good that the efficiency of pick ups determines how well the ensemble performs. It is the area I struggle with .

 

Agreed, modern RTR rocks, the motors and 2-stage drive with the motor mounted in a cradle, enuring good meshing, are powerful and efficieant enough for my purposes and slow running with smooth stops & starts is effectively guaranteed out of the box, and is usually pretty good once the loco has beeded in.  The pickups are softer than the traditional phosphor-bronze strips we had to manage with 'back in the day', when good slow performance was a juggling act between effective pickups and the friction of them, powerful enough motors to overcome the friction at low voltages, and perfect gear meshing, harder to achieve the higher the gear ratio. 

 

But this is a K's kit, very much an 'old school' loco, albiet with split pickup and no wipers.  It should run smoothly, and it does once it is on the move, and it stops beautifully; my problem is the starting.  Bare chassis no worries, I can give the fw a tweak and off she goes, but once hte bodyshell is on...

 

Been thinking about this overnight, and another idea has occurred to the puddled mess that serves as the mortal remains of my brain; perhaps the magnets are weak and the motor doesn;t have enough grunt to overcome the starting friction and inertia reliably (it's about 50% success rate starting forwards and probably 70% bunker first).   I will test this hypothesis with a finger in front of the chassis to see how hard it tries to push me out of the way; I suspect it will stall rather than spin, as the wheels seem quite 'grippy'.  Maybe re-magentising the magnets will solve the problem!

 

5 hours ago, 1466 said:

Do you remember P.D. Hancock’s solution ? He inserted a pin into the worm drive so that the motor initially revolved under no load . Having overcome starting inertia and engaged the pin  , it then took up the drive thus smoothing out the start of the train .

Hope this helps .

 

I am not familiar with this solution, and would like to know more!  Where and how is the pin placed and how does this free the motor up to run unloaded, then power the loco with the pin 'engaged' without taking it back out of drive every revolution; I can't envisage this, probably more to do with my lack of engineering understanding than your description, Ken!  I would be grateful for any information or a link to it, it sounds like a very good idea, a sort of automatic clutch!

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Not your engineering know how , Johnster . My inadequate description.

I can recall a diagram but it was in an article about Craig and Mertonford . I’ll have to trawl through the Modeller to find it .

I may be some time….

Significantly , I can’t remember P. D. Hancock using it again . It was on a standard gauge 4-4-0 from what I recall   .

Ken 

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4 hours ago, The Johnster said:

 

Agreed, modern RTR rocks, the motors and 2-stage drive with the motor mounted in a cradle, enuring good meshing, are powerful and efficieant enough for my purposes and slow running with smooth stops & starts is effectively guaranteed out of the box, and is usually pretty good once the loco has beeded in.  The pickups are softer than the traditional phosphor-bronze strips we had to manage with 'back in the day', when good slow performance was a juggling act between effective pickups and the friction of them, powerful enough motors to overcome the friction at low voltages, and perfect gear meshing, harder to achieve the higher the gear ratio. 

 

But this is a K's kit, very much an 'old school' loco, albiet with split pickup and no wipers.  It should run smoothly, and it does once it is on the move, and it stops beautifully; my problem is the starting.  Bare chassis no worries, I can give the fw a tweak and off she goes, but once hte bodyshell is on...

 

Been thinking about this overnight, and another idea has occurred to the puddled mess that serves as the mortal remains of my brain; perhaps the magnets are weak and the motor doesn;t have enough grunt to overcome the starting friction and inertia reliably (it's about 50% success rate starting forwards and probably 70% bunker first).   I will test this hypothesis with a finger in front of the chassis to see how hard it tries to push me out of the way; I suspect it will stall rather than spin, as the wheels seem quite 'grippy'.  Maybe re-magentising the magnets will solve the problem!

 

 

I am not familiar with this solution, and would like to know more!  Where and how is the pin placed and how does this free the motor up to run unloaded, then power the loco with the pin 'engaged' without taking it back out of drive every revolution; I can't envisage this, probably more to do with my lack of engineering understanding than your description, Ken!  I would be grateful for any information or a link to it, it sounds like a very good idea, a sort of automatic clutch!

While I’m still searching, I’ll have another go at describing the arrangements.

Imagine  the driving axle with a pin sticking up . The bevel  of the conventional worm and bevel has another pin  sticking out at right angles . The bevel can rotate freely until it strikes the driving axle pin , whereupon it engages and drives . 
What is stumping me is :

1. Recall whether and how  the bevel is  free to rotate on the driving axle

2. The year it appeared.

I’ll pursue the article in the Modeller’s archive .

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6 hours ago, Siberian Snooper said:

Could you reduce the length of the flywheel and shaft, thus reducing the static lump.

 

 

 

Cut the flywheel in half lengthways complete with the shaft, you mean?  I can see what you're getting at but surely this would, unless done with machine shop precision of the sort that my latheless existenc cannot provide, put the fly out of balance, and further reduce whatever beneficial effect it has.  I wouldn't like to try it tbh!

 

 

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Yes,  that's what I had in mind. The  thought was to use a cutting disc, whilst the motor was running, so that the cut should be close to even all the  way through andleave it still balanced, although removing it and putting it on a lathe would be a better idea. To be honest it was only a passing thought, that might have been a possibility, sometimes such thoughts can prove useful.

 

 

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One would have to be 100% certain of making a vertical cut in the fly at exactly 90 degrees to the drive shaft, and while I agree that it can be done by cutting into the fly while it is spinning with the motor running, it would be much easier to ensure a precision cut with a lathe.  Even with a lathe, a slitting disc would leave a roughened surface on the new cut rear face of the fly, and a lot of very careful finishing would be needed to keep good balance; not something I'd want to mess with!  I have a friend skilled in such matters, with a lathe who could do it for me, though, so the idea's not completely off the table.  It's not a bad idea, and I appreciate the thought, Siberian, just have no faith in my ability to make a decent job of it!

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20 minutes ago, The Johnster said:

One would have to be 100% certain of making a vertical cut in the fly at exactly 90 degrees to the drive shaft, and while I agree that it can be done by cutting into the fly while it is spinning with the motor running,

I'd be a bit nervous of the amount of metal dust flying around a running motor if you did it like that!

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Another good reason not to try it!  I usually have a usb powered vacuum nozzle close to the action for these sorts of jobs, but with the magnets an' all I wouldn't want to chance it!

 

Motor contained in plastic bag to protect it from the dust, perhaps, but a goodish chance of setting the plastic on fire with the friction...

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This is almost certainly the way forward, Jamieb.  I took the plunge and cut the flywheel off, and it made a small improvement but it is pretty clear now that this motor is never going to be a reliable starter, and a replacement is the obvious way out.  It's a bit sparky as well, and it is possible that it will annoy the neighbours with TVI.  Problem is that there may be some difficulty in removing the worm, but of course if I'm binning the original motor it doesn't matter how much I mangle it getting the worm off.  Sleeving the worm should be no problem.

 

Or, of course, I could strip the whole chassis down and fit a motor/gearbox assembly, but I won't do this unless I have to!  There are other advantages in a replacement motor, not least quieter running and the possibility of some cab detail.  I've drilled a starter hole in the chimney, which is a solid casting and looks very wrong from above but is otherwise a pretty good shape.  Now, to check out the prices of gear pullers...

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Johnster do you have a vice ?

it’s possible to grip a worm gear with suitable packing . Then use a narrow punch to ease the worm off with out damage .

As for gear pullers, I can recommend the GW range . 

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A gear puller is a good investment if you're going to use it regularly but an expensive one to salvage a solitary worm gear.

If you're binning the motor anyway,I'd try and knock the shaft out as described above 

A gearbox is another idea but you'd be unlikely to be able to adapt it to the split chassis wheelsets and probably end up replacing the wheels,and then rebuilding the chassis to accommodate them!

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I have several vices, some of which are also cardinal sins, but since I'm not a cardinal I don't let it worry me too much.  None of them are actually illegal!

 

Oh, you mean that sort of vice!  Yes, and your suggested method of extracting the worm from the motor shaft is probably what I will do first off.   It is certainly worth a go if it saves me the cost of a puller, which I can't see any further use for beyond this project. 

 

Nothing been done to it today, but may do some more investigating of the old motor to see if anything can be done with it tomoz.  Off for an operating session now!

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I don't think you can get K's axle gears off K's axles without wrecking the gear or Axle or both. I have yet to succeed.

AFAIK The "P D Hancock" drive was to make the loco start with a jerk, like real ones do,  I saw a reference to it re a TT layout back in the 1970s as well. It used a worm and wheel and the worm wheel, not a bevel, a worm wheel like Triang which was a sliding fit on the axle. The worm wheel had a horizontal hole with a pin which engaged with a pin in a hole drilled through the axle.  It works well. I did it on my K's ROD. The gear needs shimming on the non pin side to keep it in line with the worm and the shims between pin and chassis and possibly worm wheel are also needed, obviously the one between worm wheel and axle pin has to be of a small diameter.  Main advantage is the worm wheel is a bit loose and self centres with a single set screw attachment a la Romford the gear often runs eccentrically.  I file flats on the axle and leave the screws slightly loose to avoid this, or some times drill right through the romford gear and the axle and secure with a pin or split pin.  It works.  So does the K's flywheel, the flywheel and gutless motor give smooth acceleration, I have a 43XX with a cab full of flywheel which makes a Dapol 43XX look very silly, especially on filthy track, sometimes it needs a bit of reverse to get it away,..

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The 44XX in the photo is not the K's short bunker variant.  They bolted a 6" or so packing piece to the buffer beam and lengthened the bunkers on 44XX (and 45's up to 4554 I believe to lengthen the bunkers. Post WW1 4555 on had long frames from new.

The worst feature of the K's 44XX has to be the cylinders, grossly overscale, far too low, yuck.

44XX /45XX and 46XX had the small cylinders 24" stroke cylinders , Just about everything else GW outside two cylinder had the 30 " cylinders,   All the cylinders were the same cylinder and half smokebox saddle castings they were not handed hence had to be horizontal.

The cab roof difference is questionable, They were built at Wolverhampton (44XX, 4501-10)

and Swindon, they had canvass covered wooden roofs as built and all had steel sheets added later. 

The smokebox, cylinder, centre wheels, safety valve, chimney relationships were fixed by the standard components used and were the same on 44XX and 45XX.  The leading drivers were moved back as were the trailing ones and the coupling rod centres remained the same though I believe the rods themselves may have been different. The changes were the frames which were batch built in sets of 10   I believe that is 5 locos at a time, marked out in chalk and made in a slotting machine.   I believe theses were the only non standard batch of frames made for 6 coupled 2 cylinder locos.  The big ones had the plate frames terminate in front of the leading coupled axle, The 4-6-0s have a cover behind the slidebars to hide the fact there is no plate frame above the bogie!   Trouble is while writing this I'm not getting on with my K's 44XX. I have reprofiled the cab cut away to a more rounded profile and am weighing up options.  Big computer motor or K's with flywheel...  I'll see how the Johnster gets on.

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