Bases for track laying

[doggeface]

[i]It is now just on 3 years since I took up my P4 track and reconverted the stock to 00. The reason for the dramatic action was simple -- it was proving very near impossible to have any section of track or point work to consistently allow stock to roll on it. I spent endless hours fighting track errors only to find that the next days brought more of the same. Almost always the cause was warping either of the track formation or the base under. My old house bends and wrinkles as the seasons pass and the humidity runs through it's range.

I was deeply convinced that I was not the sole modeller tormented by these problems but then I read a letter from Martin Goodall (1044) and the first indication of the other P4 world showed itself. I have remained allied to P4 whilst seeking out any further useful indices to possible remedies.

The letter in News 192/3 have outed several details which support my angst!

Track components are not of consistent quality. Track needs to be laid on bases which would double as a marking out Table! I have used 17mm marine finished floor panels but this is defeated by the use of 5mm thick insulating panels. Failure to employ them results in an overly noisy operation. I also made a combined Brook - Smith sleeper (point work) and plastic chairs for simple track. This regularly failed due to adhesive failure. For several years I sought the recommended type but it was on the banned P.O. List I did get some from Ireland in 2013 but have no idea if this can be repeated.

As I have no time for the "Plank" so beloved of the exhibitions but wish to operate end to end with all those operations avoided by the various gauge exhibitionists including having all stock in view and still hanker for "Proper" gauge track and large curves it leaves me to think of deeper wheel flanges to handle the problems which are not going to disappear . P4 or any other gauge of 4mm is not truly modeled but of reduced scale (linear application only). To model it requires serious changes to environment or material. If I were a little cleverer I could no doubt work out the necessary flange depth to carry the load. A glance at any narrow gauge railway instantly conveys the point that it looks rather over-scale in the wheel dept!

The final problem area is the supply chain which relies on suppliers being on or off the ball , with or without stock and a postal service which is becoming hyper expensive . This unfortunately affects all aspects of our life! /i]

[Paul Townsend]

[i]It is now just on 3 years since I took up my P4 track and reconverted the stock to 00. The reason for the dramatic action was simple -- it was proving very near impossible to have any section of track or point work to consistently allow stock to roll on it. I spent endless hours fighting track errors only to find that the next days brought more of the same. Almost always the cause was warping either of the track formation or the base under. My old house bends and wrinkles as the seasons pass and the humidity runs through it's range.

I was deeply convinced that I was not the sole modeller tormented by these problems but then I read a letter from Martin Goodall (1044) and the first indication of the other P4 world showed itself. I have remained allied to P4 whilst seeking out any further useful indices to possible remedies.

The letter in News 192/3 have outed several details which support my angst!

Track components are not of consistent quality. Track needs to be laid on bases which would double as a marking out Table! I have used 17mm marine finished floor panels but this is defeated by the use of 5mm thick insulating panels. Failure to employ them results in an overly noisy operation. I also made a combined Brook - Smith sleeper (point work) and plastic chairs for simple track. This regularly failed due to adhesive failure. For several years I sought the recommended type but it was on the banned P.O. List I did get some from Ireland in 2013 but have no idea if this can be repeated.

As I have no time for the "Plank" so beloved of the exhibitions but wish to operate end to end with all those operations avoided by the various gauge exhibitionists including having all stock in view and still hanker for "Proper" gauge track and large curves it leaves me to think of deeper wheel flanges to handle the problems which are not going to disappear . P4 or any other gauge of 4mm is not truly modeled but of reduced scale (linear application only). To model it requires serious changes to environment or material. If I were a little cleverer I could no doubt work out the necessary flange depth to carry the load. A glance at any narrow gauge railway instantly conveys the point that it looks rather over-scale in the wheel dept!

The final problem area is the supply chain which relies on suppliers being on or off the ball , with or without stock and a postal service which is becoming hyper expensive . This unfortunately affects all aspects of our life! /i]

I interpret this as a member condemning P4 as unworkable with the construction techniques he adopted
As plenty of other bods have it working in worse climates than his, I suggest his failures are down to adopting incorrect materials or poor implementation or both.

[Noel]

Almost always the cause was warping either of the track formation or the base under

I have used 17mm marine finished floor panels but this is defeated by the use of 5mm thick insulating panels

So, you have given the materials used, but no data on how you used them. How were the baseboards constructed? Why 5mm insulating panels, what were they made of and how were they fixed?

I also made a combined Brook - Smith sleeper (point work) and plastic chairs for simple track. This regularly failed due to adhesive failure

Brook-Smith track used soldering to rivets, not adhesive. Plastic chairs attached to plastic sleepers with the appropriate solvent produces trackwork which is pretty robust. I recently recycled some I made 20+ years ago; recoveringthe rail was possible, removing chairs from sleepers mostly was not. [The track was reasonably OK incidentally despite several house moves and prolonged residence in someone's loft.] What adhesive did you use?

You make no mention of wheelsets, weights of vehicles or chassis construction methods, all of which can produce problems even if the track is perfect.

The problems which you seem to be having appear to be too fundamental to be solved by the use of slightly deeper flanges. Given the problems you identify with baseboards, does everything now work OK with the return to 00, or are you still having problems?

Noel

[dal-t]

Peter, if you are looking for Butanone en France and reckon you can handle a litre of the stuff, you might try here. I haven't yet had to buy any since moving here, but will do next time I try some tracklaying and I'll use these people if I haven't found anyone else. It is also worth scanning the 'specials' in Lidl - I got my current can of Xylene from there, saved the postage from Germany.

[doggeface]

Hi Paul, Nice to find you in the usual good form. I have no doubt that there are simply hundreds of "bods" who have succeeded in their P4 endeavors . I am now, equally sure that there is an equal (being generous) number who have not been so successful ! We (the failures) are therefore deemed to be "doing it all wrong"! You ignore my point regarding other heftier narrow gauge systems needing deeper flanges and wider treads than would attract the "scale" description.

[doggeface]

Hi Noel,

My base boards are of 2 x 1 " x- braced Frames. They vary in length from 1M to 1,4M. The T&G panels (17mm) with an impervious finish are fixed done via screws and packing pieces pieces to mitigate the horizontal transitions. I decided to follow the floor contours to generate changes of loading. My Greek square type spiral layout gives approx 16M terminal to terminal. Over the past 10 years I have clad the surface with rectangular sheets (approx 50 x 40 cm) of 5mm compressed wood chip which is designed for parquet silencing. These sheets are a perfect end on fit with excelled square corners.It also is easily sanded to any desired shape. I have never had a moments trouble with 3 large 00 systems. This material can be built up to 3 layers when laying horizontal sidings from main lines on the grade. This use of double thickness allows tunneling for point operating rods etc and cabling.
Now having constructed track without managing to get real Butonol (many seem to claim to be but never really worked) and having found myself having to leave sleepers attached to paper backing for fear of wrenching the plastic sleepers from the rail !This was not the plan!

So, yes, the same baseboards work well on 00 finescale and there are one or locos out of some 75 which regularly playup. I have mostly modern or modernised RTR stock which ranges from new to 35 years old and cover steam & diesel __ all DCC and one with sound! About once per month I find a track problem where joints try to change level or to separate.

The big difference between the very similar P4 schema and 00 is that the 00 is pinned and the P4 glued (as recommended).

I have a large box of P4 point and trackwork. It continues to shed chairs !

I am still inclined to lay a trial track with a clean start (I will look at the site for Butonol) Thanks dal-t

[Paul Townsend]

Hi Paul, Nice to find you in the usual good form. I have no doubt that there are simply hundreds of "bods" who have succeeded in their P4 endeavors . I am now, equally sure that there is an equal (being generous) number who have not been so successful !

Evidence for this assertion is ...?

We (the failures) are therefore deemed to be "doing it all wrong"!

I did not suggest you were doing it ALL wrong but that the situation you described suggests at least something below your rails is wrong.
If you used unusual materials or methods I wonder what trials you did before committing to a lot of work that has clearly frustrated you.

You ignore my point regarding other heftier narrow gauge systems needing deeper flanges and wider treads than would attract the "scale" description.

True because I don't understand its relevance. Also I am not an expert on prototype NG railways and have never modelled them.
I try to only comment on things that I know a bit about.

[billbedford]

Now having constructed track without managing to get real Butonol (many seem to claim to be but never really worked)

Now we can see the real problem. Dal-t suggested you find some Butanone, the solvent for ABS plastics. This is not Butonol.

Some times I wonder why kit manufacturers spend so much time producing detailed instruction when so many people can't be a***d to read them properly.

[dal-t]

Interesting. In fact I didn't read, I cut-and-pasted from C&L's site and posted the link from the results, not noticing that Google had amended my search term. Butanone (CH3C(O)CH2CH3), I now understand, is derived from Butanol (C4H9OH) and is a common solvent. Butanol is an alcohol and is also widely used as a solvent (and to reduce soot in diesel fumes). I'm not a bio-chemist - perhaps someone who is could explain to us the vital differences between these two related substances. Oh, and Butanol can apparently be purchased in France from here - just about the same price as its sister.

PS Can't help congratulating myself on not referring to Bill's mention of instructions - at least it confirms he knows they exist ...

[doggeface]

Thanks guys, I needed a good giggle (or snigger). The difference in Butonone and any other Buto ---- is that the stuff I have is MEK ! I have quite a few frets and mini kits which have no obvious assembly routes but the worst are some of those with instructions !

My immediate need is for a supply of plastic chairs (apart from C&L). Any ideas ?

[Guy Rixon]

The solvent known in the UK as Plastic Weld is supposed to weld ABS:

http://www.ebay.co.uk/itm/like/13126994 ... 108&ff19=0

Could you get a few bottles delivered by courier rather than post? That would work round the postal embargo.

[doggeface]

Hi Guy, The stuff is coming to me from Manchester by a certified carrier. It worked out as marginally cheaper than Amazon France.

Regards

Peter

[doggeface]

[b]Well I have enjoyed the sun for two weeks and scratched around my boxes and begun construction. I should say reconstruction as I am repairing what I can whilst the waiting time for postal deliveries runs off. I laid a 1 metre section on a gentle curving gradient and posed a single B set carriage thereon! This Airfix model has good bogies and accepts P'4 wheelsets without any mods!

The big plan now is to split off a whole circuit of the present 00 layout and lift it . The base inway of that track bed to be lifted and replaced. This will give me a series of stations which reflect the Franco Spanish crossings with dual gauge tracks!

It will leave one MPD isolated from the 00 system so I will construct a suitable fly over . This will suffice until that MPD becomes a P4 arrangement. There will be a little soul searching rooting out the nonconvertible ( non 1/8th or 3mm axles ) as I am very fond of the oldies which have been modernised or improved to perform like their modern equivalents .

To achieve the metre of track laid today I firstly refixed or replaced the Exactoscale chairs using MEK which seems to be a good fixer- I dare not claim too much for it just in case it all turns to ashes again! I then used the copier to produce a straight track schema on 80 gm paper. I fixed the track section to this schema using a dab of paper glue under the centre of each sleeper. When it has dried I cut between the sleepers on the inside of the curve to the centre point. This allowed the two sections to set to the desired form without any further force or restraint. It sat flat on my compressed wood particle track bed. The Carriage rolled up and down without protest, derailing or other nonsense. [/b ]

When (and if ) a satisfactory system is developed I shall replace the rail joiners with fishplates and fix the track in place with the same paper glue.(section by section)

I found a pair of invoices from 2011 and could not believe that things had become so expensive !

[doggeface]

Well, track has been repaired or built new and laid across the swing bridge. This note is to show the first train into a station.It consists of an 8750 pannier and half of a B set! This is the entire rolling stock at present. I am attempting to post a photo as this is the real exercise for today!

PIC_1007.JPG

The area in the foreground is where a dual gauge crossing is being made to enable the MPD to function and provide the junction for the P4 track to approach from a differing area.

The swing bridge proved to be very demanding for the P4 track as it has no easy way of visually checking vertical errors and does tend to move in the way of timber frames!!The 4672 Pannier has been in 00 and P4 gauge several times now and has also survived open chip surgery on it's decoder almost as often!

PIC_1008.JPG

[Guy Rixon]

... The swing bridge proved to be very demanding for the P4 track as it has no easy way of visually checking vertical errors and does tend to move in the way of timber frames!! ...

I've seen similar situations in the building of scientific instruments, where a rotating carriage has to be locked into place repeatably and to high accuracy. The preferred solution was a ball-ended detent pin engaging a conical notch.

In this mechanism, the conical notch is in the rim of the rotating piece, with the mouth of the cone facing out along a radius of the rotator. The coned bit is like a large version of a 4mm-scale bearing for pin-point axles. The pin drives into this notch from the fixed frame along the axis of the cone. As the ball end of the pin enters the cone, it takes up the play in the rotator's bearing and centres the edge of the rotator both vertically and tangentially to the rotation; i.e. it locks the edge of the rotator into a fixed and repeatable position with respect to the frame.

Suppose that you could fit one of these to your moving bit of baseboard, then lock it, then lay track across the join and cut it. You'd then have two pairs of rail endings that would realign reliably each time the bridge was swung closed.

You can do similarly with a cylindrical dowel, but it will never be as accurate as the ball/cone mechanism and still retract. The clearance necessary to get the dowel in and out will degrade the positioning accuracy. The ball/cone approach needs no clearance between the ball and cone in its closed position, and very little clearance between the pin and its housing.

[doggeface]

Hi Guy, The possible movement is tri-planar (very similar to the problem of shooting at a plane from a pitching and rolling ship!). The principle of the conical locating and locking bolt is very attractive. Such things are very hard to locate in France as Retail and Commercial do not co-exist. In my past life it was easy to source almost everything easily ! I have to survive via eBay and it's often very sparse technical data!

The present system is a simple vertical brass 1/8" rod passed into holes in hardwood holes. When all is well I will probably replace the female holes with a brass tube and epoxy it in. The assembly is horizontally tensioned against HD micro switches which open circuit the approaches at each end. These are adjustable and keep it solid. Nothing will prevent the floor from rising and falling with the humidity and temp as it has done for the past several hundred years. This is why the bench work above is robust and capable of remaining cantilevered when necessary!

The 00 fine scale will tolerate errors which the P4 simply will not. The errors which have caused derailing (at slow speed or hand propelled have been measured at between 0.1 & 0.2 mm) . These errors suffice to cause the wheel sets to jump the flanges off into space!

If you know of a source of such bolts then I am all ears!

Regards

Peter

[dal-t]

If you know of a source of such bolts then I am all ears!

Me too. I've occasionally wondered why ordinary inter-baseboard locators don't use the taper principle instead of parallel bolts, so if cones/sprung balls can be obtained without having to machine them yourself, I'd be keen to give them a try.

[jon price]

A quick search threw up these sprung ball thingies (halfway down page). It is in the US, but I would guess that they could be found elsewhere. The cone should be drillable in a block of metal? http://www.jwwinco.com/products/section ... l-plungers

[Guy Rixon]

When we used these detent pins in instruments they were different from the kind in Jon's link.

The ones Jon found are internally sprung, with the ball retracting along the inside of a tube. It looks as if they work like a posh version of a ball-catch on a cupboard door: the pin is fixed and the ball retracts into it to release the catch.

The ones I remember had a moving pin driven in under power, variously by a solenoid, a servo or a stepper motor. The pin was solid and the ball was turned on on the end of it, usually a simple half-sphere. Any spring in the mechanism was between the pin and its drive.

The internally-sprung pin might just work! The limiting factors are the force of the spring (does it hold the rotator firmly enough?), the size of the ball (is there enough motion against the spring to unlock the rotator?) and the tolerance of the ball/tube interface (can it move sideways in the tube enough to spoil the positioning?). If it meets these criteria, then clearly it's the easier and better solution.

If a moving, rigid pin turns out to be necessary, then its ball end can just be turned on the end of a suitable bit of rod, provided that the rod is a close, sliding fit in an available bit of tube. A ball isn't strictly necessary; a round pin with a flat end would still centre repeatably in the cone, but a ball-ended one is less likely to lose precision by the edges wearing away (which is probably a non-problem for a model railway).

Disclaimer: I have never actually built one of these devices. I have only written control software for equipment using them. In my experience, they work very well when made properly.

[jasp]

Ball plungers are available from RS
Jim

[Winander]

Ball plungers are available from RS
Jim

Still sprung balls as far as I can see. I think the point is these are little better than ball catches for doors. If I understand correctly, what Guy is describing is a solid plunger with a half sphere on the end that is pushed into a conical 'socket' by a solenoid or similar mechanism. The accuracy is achieved because a (half) sphere is seating itself into a cone so the contact area is minimal but there is contact around the entire circumference of the sphere, and if both are aligned correctly, they will always provide an accurate location, despite wear - although it is doubtful that would occur in our likely applications. By contrast, a cylinder (bolt) locating in a tube must have allowances built in to enable the bolt to slide.

[Terry Bendall]

By contrast, a cylinder (bolt) locating in a tube must have allowances built in to enable the bolt to slide.

Yes it will but only a few thou. - perhaps no more than 3. Brass rod in brass tube is unlikely to have those sort of tolerances so it is a case of making. or having made something to do the job. An easy job for a lathe owner but more difficult for those without.

A variation would be a sliding bolt with a very slight taper into a tube. If the assembly is mounted horizontally and the bolt slides into the tube until the taper locks it, it would cope with both the vertical and horizontal alignment. A bit difficult to work with a solenoid which usually has a fixed length of movement and if it does not move the whole distance of the travel the coil will still be energised and will probably overheat.

You would need to build in some adjustment with oversized holes or slots.

Terry Bendall

[Guy Rixon]

The solenoid drives I remember drove the pin out of engagement. When the solenoid was turned off, a hefty spring brought the pin back into its cone.

Concerning the springs, you'd need one strong enough spring to resist the vertical and tangential forces on the rotator. For example, this morning I found some spring plungers with a pre-load of 10 N - i.e. the plunger will start to retract when axial force is 10 N or the weight of 1 Kg (in round numbers). If the half-angle of the cone is 45 degrees, then half the weight bearing on the end of the rotator is transmitted along the pin: 2kg will start to move the pin back. Plungers are available with stronger and weaker springs.

[doggeface]

Since having received many useful comments regarding the bridge closure position I put my mind to using such material and technology that is to hand. Given that the stable platform is the receiving horizontal plate and the variable is the swinging arm I looked for a way in which to ensure the rest position of the swing was repeatable. The horizontal can be achieved by a simple peg (as now) The angle of incidence of the swing is ~45° so there is plenty of lee way there. The vertical can be assured better if a plate is fixed to a dropper arm under the swing section that passes over the main bearer so that it passes under the same position and a spring loaded plunger mounted facing up to bear against the lower surface of the main bearer.
For the moment it is behaving and the faults (very few now) are due to tracking or gauging errors.

Just after the infamous bridge departure point I have made up and fitted a dual gauge crossing.

PIC_1017.jpg

This crossing works well and is pinned down only. A turnout has to be made and fitted on either side and the further straight track is not fixed as it is being tested.

The centre rails and isolated nose units of the x_ing are not yet powered as I await the supply of a 4 way 3 pole toggle sw. The actual crossing locations have been filled with modelling cement in order to provide a flange support. I have chosen to ignore the use of check rails despite the S4 section having a curve . I have tried a mixed bag of large (N15) and Cl 37 and Pannier tanks with old and new rolling stock.


Having about 5 M of P4 track which works (the MKE works) enables the Pannier and carriage to take several runs each time I think about it in Push and Pull mode. As both use the rather slack small tension lock couplings with their tendency to over ride and lock up it is close to miraculous that they perform without any problems.

Making up the turn outs is slow as I am obliged to make my own jigs and gauges but it is getting there and my blade and nose setting out boards were still around.

All in all , things are looking up. One recurring thought is that having solid chassis kit really does demand a whole level extra of care compared with the sprung or compensated kit!

I look forward to seeing some faces at Wells on Sat next __ Calais strikers and potential immigrants willing!

PIC_1012.jpg

PIC_1014.jpg

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Regards to all

Peter