Trials and tribulations of a (very) average P4 Modeller

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David Thorpe
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Trials and tribulations of a (very) average P4 Modeller

Postby David Thorpe » Tue May 29, 2018 1:50 pm

About 45 years ago, when I modelled in 00, I built a DJH Caledonian Jumbo. Needless to say, in the days before High Level (or any other) gearboxes I never got it to run properly and it was put away for later. Later turned out to be this year, when I decided to convert it to P4. A problem arose early on when my grandson dropped the loco onto a hard floor causing damege that might have normally been considered a write off, but I'd paid good money for that model and so I repaired it. Then I had to cause a lot of damage myself by carving away an enormous anount of whiute metal to fit the P4 chassis (Gibson mainframes), High Level gearbox and motor. I got a bit carried away sometimes with the carving which necessitated my then having to do a fair bit of filling. The DCC decoder went into the tender where I arranged wiper pickups on all 6 wheels (CSBs) but none on the loco (I hate fitting pickups on loco wheels).

And it worked. But not really very well. The chassis ran freely, but either the pickups or the decoder were, I felt, not performing well and needed checking. The pickups were the most obvious candidates, so I took the tender chassis apart and rebuilt it for split axles which I then made. I rebuilt the chassis using the original wheels, now with shorting strips. It didn't work (at all). I discovered a small short on the PCB which collected together all the wiring in the tender. I cleared it and the loco worked but not as well as I'd hoped. Suspecting it might be the decoder i removed that, rewired for DC, tested, but there was no improvement. Then I felt that the tender CSB springs were maybe too weak so I removed them and replaced them with stronger ones. Put it all back together again and Eureka! everything worked well. So I removed the chassis from the bodies (loco and tender) to reinstate the DCC wiring and decoder. Put it all back together and of course it didn't work (at all). Checked all wiring. Eventually found that a wire had come away from the motor . Repaired, put everything back on the track and it ran beautifully! I ran it up and down a few times until a sudden and ominous stop. The rear left hand coupling rod had come off and as a result the rear wheels were no longer properly quartered. I duly requartered the rear wheels, straightened the coupling rod, put all back together, tested for free running without motor, secured (soldered) the errant coupling rod nut back on, tested, wonderful.

Until, that is, it got to my admittedly doubtful 3-way point, where it derailed. Discovered that the gauge narrowing (as has happened to most of the points I built with Exactoscale chairs) had worsened (hot weather?). I'm just about to begin taking the switch rail off for more filing and adjustments...... The problems never seem to end!

At least the Jumbo still runs very nicely.

DT

Enigma
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Re: Trials and tribulations of a (very) average P4 Modeller

Postby Enigma » Tue May 29, 2018 3:50 pm

All sounds very familiar..........................

But you'll get there in the end.

When that end appears is, however, another matter entirely!

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RobM
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Re: Trials and tribulations of a (very) average P4 Modeller

Postby RobM » Tue May 29, 2018 4:47 pm

I'll echo Paul's comments.
Sometimes this hobby is very frustrating......today I was fitting a continuous hand rail on a RHS 0-6-0 and without thinking soldered on the front hand rail knob before bending up the wire..... :shock: Ended up trying to unsolder the thing only to break it......so had to drill it out and more or less start again. Hey ho....yes, the trial and tribulations but when it goes well you feel good.....
Rob
http://www.robmilliken.co.uk
Updated December 2016

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Will L
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Re: Trials and tribulations of a (very) average P4 Modeller

Postby Will L » Tue May 29, 2018 5:33 pm

Persistence is the hallmark of the successful modeller.

It dosn't just apply to modelling. As a big computer systems person who did lots of system support, we had a saying "Disasters only ever get worse". What we were alluding to was that as soon as something goes wrong, every attempt at fixing it always inclined to uncover more things which arn't working right. So you fix them too and yet more things.... You didn't keep your job if you weren't persistent. I rather suspect this is a lesson which the TSB had just (re)learned the hard way.

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John Bateson
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Re: Trials and tribulations of a (very) average P4 Modeller

Postby John Bateson » Tue May 29, 2018 6:09 pm

Persistence is the hallmark of the successful modeller.


Will,
Should that not be 'Perseverance'? (Rainhill trials :mrgreen: )
John

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Tim V
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Re: Trials and tribulations of a (very) average P4 Modeller

Postby Tim V » Tue May 29, 2018 6:36 pm

It's not the arriving, it's the journey that counts.

And, you have learn't a lot of lessons, maybe had some fun (or not). Next time you'll probably do it quicker.
Tim V

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Will L
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Re: Trials and tribulations of a (very) average P4 Modeller

Postby Will L » Tue May 29, 2018 6:39 pm

John Bateson wrote:
Persistence is the hallmark of the successful modeller.


Will,
Should that not be 'Perseverance'? (Rainhill trials :mrgreen: )
John

I suppose that wouldn't be an Novelty Without Parallel and no Cyloped(ic) objections Rocket to mind

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David Thorpe
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Re: Trials and tribulations of a (very) average P4 Modeller

Postby David Thorpe » Tue May 29, 2018 8:26 pm

Tim V wrote:And, you have learn't a lot of lessons, maybe had some fun (or not). Next time you'll probably do it quicker.


I've actually had quite a lot of lessons - this is my ninth working P4 loco - but they don't seem to make an awful lot of difference. It's been one of the most problematical because i was trying to convert an old whitemetal kit which had been built for 00 and was probably designed before P4 was ever thought of. It was certainly exasperating. If I'd been building the kit from scratch I might well have done it a lot quicker (or just thrown it in the bin). There's another DJH whitemetal kit waiting for me so we'll see whether that'll be true or not.

DT

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Mark Tatlow
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Re: Trials and tribulations of a (very) average P4 Modeller

Postby Mark Tatlow » Tue May 29, 2018 8:55 pm

David,

I also found problems with the switches of Exactoscale turnouts.

To be fair to them, I actually think it is how we build them the gauge tends to push the switchblades apart slightly, giving a false feeling that when the solvent goes off they are correctly gauged.

Exactoscale's gauges have a +0.1mm, +0.2mm (etc) gauges and I use one of these slightly larger ones through the switch. It does go a long way to making these work better.


Mark
Mark Tatlow

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David Thorpe
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Re: Trials and tribulations of a (very) average P4 Modeller

Postby David Thorpe » Tue May 29, 2018 9:17 pm

Mark Tatlow wrote:David, I also found problems with the switches of Exactoscale turnouts. To be fair to them, I actually think it is how we build them the gauge tends to push the switchblades apart slightly, giving a false feeling that when the solvent goes off they are correctly gauged.


Yes, I think that's largely correct - as I now understand it, the Exactoscale chairs are made to hold the rail at a prototypical angle and if you then build your track using standard society or other conmercial gauges, they hold the rail upright. When they're removed, the rail slowly relaxes into its slightly angled inward tilted position, resulting in gauge narrowing. Unfortunately, I (and I'm sure many others) didn't know that when we built our track and I'm now having to correct much of my pointwork which is very tedious. I do think that this feature should be made plain on Exactoscale packaging. If I was to build any more points I'd really like to revert to ply and rivet if only there were cosmetic chairs available that would fit easily over the rivets.

DT

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jon price
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Re: Trials and tribulations of a (very) average P4 Modeller

Postby jon price » Tue May 29, 2018 10:01 pm

So are there gauges which hold the track at the prototypical angle?

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Tim V
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Re: Trials and tribulations of a (very) average P4 Modeller

Postby Tim V » Tue May 29, 2018 11:02 pm

David Thorpe wrote:I've actually had quite a lot of lessons - this is my ninth working P4 loco - but they don't seem to make an awful lot of difference. It's been one of the most problematical because i was trying to convert an old whitemetal kit which had been built for 00 and was probably designed before P4 was ever thought of. It was certainly exasperating. If I'd been building the kit from scratch I might well have done it a lot quicker (or just thrown it in the bin). There's another DJH whitemetal kit waiting for me so we'll see whether that'll be true or not.

DT

I have an old K's tank, converted to P4. It's over 40 years old, and there is a Bachman version out, but I like it as a model.
Tim V

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Noel
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Re: Trials and tribulations of a (very) average P4 Modeller

Postby Noel » Wed May 30, 2018 10:29 am

David Thorpe wrote:the Exactoscale chairs are made to hold the rail at a prototypical angle


The same is true of C & L chairs.

David Thorpe wrote:if you then build your track using standard society or other conmercial gauges, they hold the rail upright.

jon price wrote:So are there gauges which hold the track at the prototypical angle?


The Society's rectangular gauges, and most roller gauges, used carefully, won't force the rails upright. The main offenders in this respect, as I understand it, are the triangular gauges [apologies if this is not so; I have no experience of these myself, having never used them]. Having built points under gauge at the toe when I started I now usually put a small joggle in the straight stock rail at this location, which seems to solve the problem for me.
Noel

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David Thorpe
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Re: Trials and tribulations of a (very) average P4 Modeller

Postby David Thorpe » Wed May 30, 2018 12:19 pm

The society's triangular gauge (or certainly the older one) is a tight fit on the rails and holds them upright. To my regret I used it quite a lot in my track building. I also used a selection of roller gauges and they too effectively hold the rail upright. I suppose it could be argued that I should have known that Exactoscale (and for all I know C&L) chairs are designed to hold the rail at an angle, but I didn't and had it not been for posts I subsequently read on this forum I still wouldn't. Personally I think that given the methods and gauges used for hand building track the insistence on a prototype angle for chairs is just getting it right a step too far. I really don't know what I'd do now if i was contemplating building some track; in the absence of suitable gauges I really wouldn't want to use these chairs again, but trying to fit cosmetic chairs over rivets that they're not actually designed to fit over is appallingly tedious.

DT

Tony Wilkins
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Re: Trials and tribulations of a (very) average P4 Modeller

Postby Tony Wilkins » Wed May 30, 2018 12:32 pm

The main issue with track gauges regardless of type is the depth of the slot intended to hold the rails to gauge. If the depth is sufficient to hold both the rail head and the foot, then the rail will be constrained in a vertical position causing problems with functional chairs. If the depth of the slot is less than this, the bottom outer corner of the claw (for want of a better description) is free to sit in the web of the rail and accommodate the rail tilt provided by the functional chairs. There is also a tendency for downward pressure of the track gauge against a flat railhead, to encourage the rails to go vertical whilst the chair is being glued. Where switch blades are concerned, the planed end of the switch blade or toe needs to be vertical to ensure a snug fit against the stock rail at the running surface. Full size switch blades incorporate a vertical twist toward the fixed end to accommodate this difference.
Tony.

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David Thorpe
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Re: Trials and tribulations of a (very) average P4 Modeller

Postby David Thorpe » Wed May 30, 2018 1:33 pm

Tony Wilkins wrote:There is also a tendency for downward pressure of the track gauge against a flat railhead, to encourage the rails to go vertical whilst the chair is being glued.


The trouble is, of course, that you need the downward pressure to ensure that the chairs (which themselves are not always truly flat bottomed) bond securely to the sleepers.

DT

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Le Corbusier
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Re: Trials and tribulations of a (very) average P4 Modeller

Postby Le Corbusier » Wed May 30, 2018 2:45 pm

David Thorpe wrote:The society's triangular gauge (or certainly the older one) is a tight fit on the rails and holds them upright. To my regret I used it quite a lot in my track building. I also used a selection of roller gauges and they too effectively hold the rail upright. I suppose it could be argued that I should have known that Exactoscale (and for all I know C&L) chairs are designed to hold the rail at an angle, but I didn't and had it not been for posts I subsequently read on this forum I still wouldn't. Personally I think that given the methods and gauges used for hand building track the insistence on a prototype angle for chairs is just getting it right a step too far. I really don't know what I'd do now if i was contemplating building some track; in the absence of suitable gauges I really wouldn't want to use these chairs again, but trying to fit cosmetic chairs over rivets that they're not actually designed to fit over is appallingly tedious.

DT

Having just completed my first piece of track building (my test track) my observations are as follows.

I bought a set of the exactoscale roller gauges as I found that the society triangular gauges held the track vertically and caused gauge narrowing once the rail was left to its own devices in the exactoscale chairs. The roller gauges simply space the track rather than hold it allowing the chairs to incline the track as intended. My experience so far is that using the roller gauges there is no gauge narrowing and all works well. Furthermore, because the track is held relatively loosely in the chairs and can move to expand and contract and because I pre curved the rail where required prior to fixing so that no stresses are built in to the system, to date I have not used any rivets and relied solely on the chair bond to the sleeper. To date after 7 months of testing nothing has moved or become de-bonded ... so fingers crossed. Come what may re-bonding a chair is a relatively simple operation.

So as a newbie to all of this, so far so good :thumb
track laying - 3.jpg
ballasted track - 1.jpg
Tim Lee

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David Thorpe
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Re: Trials and tribulations of a (very) average P4 Modeller

Postby David Thorpe » Wed May 30, 2018 5:29 pm

I didn't know about these Exactoscale gauges which appear to offer a solution to the gauge narrowing problem although I'm not quite sure how they would hold the track down and in place during setting. They are currently being offered by C&L for £10.80 - if there are likely to be any problems with supply I wonder if it would be worthwhile the stores getting some of these in?. I was using a different variety several of which I've had for a long time and served me well when I built trackwork using ply and rivet - see picture below. As you'll see these effectively hold the rail vertically. With hindsight I would strongly advise against using gauges like these for building track with plastic chairs!

rollergauge2.jpg
rollergauge2.jpg (103.56 KiB) Viewed 583 times

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Le Corbusier
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Re: Trials and tribulations of a (very) average P4 Modeller

Postby Le Corbusier » Wed May 30, 2018 6:43 pm

David Thorpe wrote:I didn't know about these Exactoscale gauges which appear to offer a solution to the gauge narrowing problem although I'm not quite sure how they would hold the track down and in place during setting. They are currently being offered by C&L for £10.80 - if there are likely to be any problems with supply I wonder if it would be worthwhile the stores getting some of these in?. I was using a different variety several of which I've had for a long time and served me well when I built trackwork using ply and rivet - see picture below. As you'll see these effectively hold the rail vertically. With hindsight I would strongly advise against using gauges like these for building track with plastic chairs!

rollergauge2.jpg


As far as the holding down is concerned, i simply flooded the chairs with solvent and held them down gently with the gauges themselves for a slow count of 60 .... seemed to do the trick. I did about 10 pairs of chairs each go and found it quite therapeutic. The gentle pressure also kept the rail to gauge while the solvent set. I could hold both rollers with the one hand (thumb & ring finger) allowing the solvent to be applied with the other. .... other methods might be quicker or simpler ;)
Tim Lee

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jon price
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Re: Trials and tribulations of a (very) average P4 Modeller

Postby jon price » Wed May 30, 2018 8:46 pm

Well after my query on gauges, I checked some of the plastic chair and sleeper turnouts I made several years ago, and they seem OK. All of my roller gauges just hold the top of the rail, and don't grip the whole rail. So for me it seems this is a non issue.


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