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P4 'Test Track' with Bullhead and Flat Bottom Rail Permanent Way


Colin parks
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I tried staining ply sleepers in the distant past and found that chair to sleeper bonding wasn't always as good as it could be. Now I just paint them with Rowney black poster paint after construction, with burnt sienna along the rail sides, the latter helping to bond the rail to the chairs when dry. After ballasting I spray the track with more of the same colours to taste. The overall effect seems fairly reasonable.

 

There are a few shots here -post #15 might be the best - which may show whether you think it worth trying this method:      http://www.rmweb.co.uk/community/index.php?/topic/116233-theatre-indicator-on-platform-starter/

 

Izzy

Hi Izzy,

 

That layout of yours looks really good.  Facing point locks and all!   I might try rubbing down my stained timbers and see if that helps. I am betwixt and between, having already stained half the woodwork and the other half not.   

 

Colin

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More progress from earlier today.  The sleepers are now all laid on this board, leaving just the catch point and the timbers which will have soleplates added (the upturned loose ones).  These timbers have to be set lower to allow for the thickness of the soleplates, which will be fashioned from 10 thou. plasticard.   I am wondering about the merits of pre-staining the sleepers, as the stain I have been using is leaving a powdery surface on the timbering stained so far.  This might affect the bond between the plastic chairs and Pandrol bases and the plywood - not a good idea..

 

attachicon.gifIMG_8322 (2).JPG

 

attachicon.gifIMG_8324 (2).JPG

 

Here are a couple of images of the three flat bottom rail turnouts, with corrected crossing on the l/h one.  The rail assemblies are just loosely laid in position, but the slinky appearance of the B8 geometry and Templot's facility to insert turnouts in curves of any radius can be seen here.  Much to do before laying anything permanently on the baseboard, but it is slowly beginning to come together.

 

I will have to investigate why there is a marked bulge in the timbering on the l/h side of the tandem.  Must have been shoving the timbers about too much.

Probably wouldn't be noticeable if aligned from the outside of the formation.

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Probably wouldn't be noticeable if aligned from the outside of the formation.

HI Siberian Snooper,

 

I think that the bulge is caused by some timber shoving in Templot in the wrong direction.  I only found the way to invert the shoving from one end of a timber to the other relatively late in the design process.  The track plan as stuck to the board should have been proof-read prior to fixing it down.  There are a few conflicts in timbering to sleepering spacings which I am working around.  

 

The good thing about the bulge is that it is far less problematic than a deficit!

 

Colin

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  • 4 weeks later...

Some queries about chairing a tandem turnout.

 

I might have caused myself some issues by combining two diverging crossings of the same angle namely 1:8.  I could be wrong, but this seems to have created conflicts with chair positions in quite few places leaving little room for adjacent chairs.  I have temporarily threaded on some M1 small chairs (all references are to C&L Exactoscale products), but maybe in some cases they should be have been L1 bridge chairs.  It is unclear to me when to use an M1 chair and when to use an L1 chair.  Here are some photos which might help someone answer this conundrum.

 

Here to the left of the check rail only an M1 chair would seem to fit, but looks intuitively wrong.

post-8139-0-40415300-1488141144_thumb.jpg

 

In the same area the check chair second from the right makes even an M1 chair impossible to fit.

post-8139-0-41175400-1488141154_thumb.jpg

.

In this view, tow of the M1 chairs could be changed for L1s, but there will be a conflict when the nearest wing rail receives its chair.

post-8139-0-46131300-1488141167_thumb.jpg

 

And what should be happening here?  Should it be two M1s nearest the knuckles followed by two L1s?

post-8139-0-86329800-1488141184_thumb.jpg

 

Here, between the two check rail gauges, there is one M1 chair that I can now see should be an L1. (Ironically, the only chair that needs to be changed is trapped between two soldered joints). 

post-8139-0-37500700-1488141196_thumb.jpg

Edited by Colin parks
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Hi Colin,

 

Don't forget there are plenty of other chairs to fit difficult places such as saddle chairs, bolted half-chairs.

 

This pic linked from the Scalefour Soc site shows a tandem with bolted half-chairs and a custom wing rail:

 

chairs04.jpg

linked from: https://www.scalefour.org/resources/trackdetails.html

 

Also a slab & bracket design for the "B" chair.

 

regards,

 

Martin.

Edited by martin_wynne
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Hi Colin,

 

Don't forget there are plenty of other chairs to fit difficult places such as saddle chairs, bolted half-chairs.

 

This pic linked from the Scalefour Soc site shows a tandem with bolted half-chairs and a custom wing rail:

 

chairs04.jpg

linked from: https://www.scalefour.org/resources/trackdetails.html

 

Also a slab & bracket design for the "B" chair.

 

regards,

 

Martin.

Thanks Martyn,

 

I suppose a chopped slide chair would make a good representation of a bolted half-chair, though more cosmetic than functional.  

 

Colin

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Interesting reading Colin. I'm not far off from making my own p4 start (finally), though I might have to redo all my templot files as I had a bit of data loss with a dead SSD on the computer (some were backed up thankfully though, but not all possibly).

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Colin

 

When building either standard turnouts, diamonds (obtuse crossings) and slips Exactoscale do have a (limited) range of chairs available

 

A tandem crossing brings up a few extra problems, to start with the first crossing may be an awkward angle, then the crossing and check rails can be much closer together than on standard common crossings (or the other two)

 

The solution I come to is first to see if bridge or small chairs can be pressed into service. Next is to see if chairs like check rail chairs can be adapted, finally I use some spare block chair (and other) parts from old obtuse and slip crossing sprues. Its a case of finding which part fits/looks best, not an exact science, but can look far better than chopping up other types of chair

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Colin

 

When building either standard turnouts, diamonds (obtuse crossings) and slips Exactoscale do have a (limited) range of chairs available

 

A tandem crossing brings up a few extra problems, to start with the first crossing may be an awkward angle, then the crossing and check rails can be much closer together than on standard common crossings (or the other two)

 

The solution I come to is first to see if bridge or small chairs can be pressed into service. Next is to see if chairs like check rail chairs can be adapted, finally I use some spare block chair (and other) parts from old obtuse and slip crossing sprues. Its a case of finding which part fits/looks best, not an exact science, but can look far better than chopping up other types of chair

Hi John,

 

Thanks for your advice.  I have now found some packets which will take care of most of the queries I had about chairing the tandem.  I seem to have avoided having problems with closeness of check rails at the expense of bringing the switch toes of the second pair of switches very close to the switch heels of the first pair and all this suspect because of designing the tandem with two 1:8 crossings (the second and third ones).

 

You are quite right about the first crossing being an awkward angle on a tandem - mine is 1:5.6.  I am going to try a crunge the 1:5 or maybe the 1:6 set of block chairs from the relevant Exactoscale  moulding into place.  I have come across a letter from Pete at C&L along with details of what kind of chairs to use on turnouts and slips.  I will be removing the M1 chairs, because it seems they are only used on slips.  

 

I also have found two packs of switch detailing chairs, with a mind-boggling array of parts, though I do recall having a diagram which might help identifying these.

 

All the best,

 

Colin

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  • 3 weeks later...

I had mentioned concerns about the proximity of the tips of the second pair of switches to the heels of the first pair.   I have now looked at the S4 Society/C&L templates, which I had not realised were available to society members.  Examining the l/hB8,r/hB8 tandem template, it turns out to be almost exactly the same as the Templot design I am working to and exactly the same in terms of switch positions.

 

After re-making two switch/closure rail components, the assembles are now behaving themselves.  Here are some warts and all pictures of the assemblies, still in need of adding the correct chairs in places.  

 

The left hand common crossing in this shot has had to be rebuilt due to the misalignment of the crossing nose, as seen here.  The [digital] camera never lies. In a rather unorthodox procedure, the point and splice rail have been extracted from between the wing rails and the point rail reshaped and re-soldered.

 

post-8139-0-31389800-1489772284_thumb.jpg

 

 

This shot highlighted the need for some more curving to the closure rail in the foreground.  The stock rail to the left has a slight kink at the end of the check rail, caused by threading on the rather tight check rail chairs. The blobby soldered joint is evidence of work in progress on that common crossing.

 

post-8139-0-55107500-1489772334_thumb.jpg

 

All issues have been addressed now, more might arise when the rails are laid on the timbering...

Edited by Colin parks
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Colin

 

It looks very good, The camera can sometimes be very cruel, though if it stops an error creeping in so much the better. I have seen one track builder use rolling bars to form curves in rail.

 

One thing that does need a bit of time in setting is the middle exit road, using standard track gauges sometimes sets the check rails in the wrong position. I would be tempted to use check rail gauges (both ways) to position the 2 common crossings

Edited by hayfield
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Thanks for your advice about the common crossings John. As it happens, I do have two check rail gauges, so I will set the straight road with those. You are right about the camera showing up all the tiny faults, but it is best to find them now rather than later!

All the best,

Colin

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  • 3 weeks later...

Some progress on the point work:

 

post-8139-0-16583700-1491946767_thumb.jpg

 

All the rail assemblies are laid in position here, with their wire droppers added.  I have been refining some alignments and, as Hayfield mentioned, the straight road through the tandem has been the trickiest part to get right.  The only issue of any note has been the slight curving of some chair bases - especially those of the check chairs.  This will mean using big weights to press them flat when it finally comes to laying the rails permanently.  

 

But there are many things to do before the rails do go down, including ballasting - a method my friend Howard Bolton advocates. This method has the advantage of getting the ballast nice and neat, which I am informed is not so easy with thick timbering, but ballasting first does mean losing sight of the Templot templates beneath - scary!

 

The appearance of the Peco Pandrol fixings look better in the photos than I had expected.  Though not exactly to scale, they are quite acceptably fine.

 

 

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Excellent work Colin, nice and steady progress. I like the idea of ballasting before fitting the rails. Will there be any need for point rodding? if so I would suggest putting the bases for the stools in before you commence ballasting, otherwise the tend not too sit flat on the ballast.

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Excellent work Colin, nice and steady progress. I like the idea of ballasting before fitting the rails. Will there be any need for point rodding? if so I would suggest putting the bases for the stools in before you commence ballasting, otherwise the tend not too sit flat on the ballast.

Thanks Siberian Snooper!

 

Re. the ballasting, the project has now expanded to include point rodding runs (inc. stools) and all the ancillary details such as trunking.  All these features will be positioned prior to ballasting.  There are also going to be some electro-magnets set in the track bed for auto uncoupling.

 

Colin

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  • 1 month later...

Re. the ballasting, the project has now expanded to include point rodding runs (inc. stools) and all the ancillary details such as trunking.  All these features will be positioned prior to ballasting.  There are also going to be some electro-magnets set in the track bed for auto uncoupling.

 

Colin

 

Now why doesn't that surprise me, expanding projects with greater detailing = pre-requiste for Colins Masterpiece :superman: 

 Been a long time but glad you've taken the leap into the black hole of  P4. Nice work thus far 

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Now why doesn't that surprise me, expanding projects with greater detailing = pre-requiste for Colins Masterpiece :superman:

 Been a long time but glad you've taken the leap into the black hole of  P4. Nice work thus far 

Hi Ark Royal,

 

Many thanks for your comments, though masterpiece might be taking it a bit far!  I am not sure how to interpret the reference to a 'black hole' - is it that once you are in one, there is no way out?  Re, greater detailing,  a the moment I am slowly working on scale point rodding, the position of which has to be planned prior to ballasting the track bed.  In theory, the rodding could be made to move realistically, but that is probably beyond my skills.

 

Colin

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Switch drive rods have been on the agenda lately.

 

Below is a picture of an adjusting crank, drive rod and stretcher bar bracket (which attaches to the side of the switch blade).  This is a prototype for the eight assemblies which will actually drive the switches.  The  yokes on each end of the drive rod and the adjusting crank are etched components from Howard Bolton, whose method of assembly has been copied for the parts seen here.  The (slightly wonky) brass tube on the drive rod represents the adjusting turnbuckle.  The part also provides an insulated join to electrically insulate the switch blade from the rest of the mechanical drive. The drive rod is in two parts.

 

post-8139-0-78776000-1495836222_thumb.jpg

 

Pictured here upside down for illustration, is one of Howard's etched escapement units which will operate the switches sub-baseboard driving the crank seen in the previous picture via a 1 mm o/d brass tube, pivoting with the movement of the escapement.  Howard explains all this far more eloquently than me in his Scalefour News articles.

 

post-8139-0-85899800-1495836233_thumb.jpg

 

 

Now with the escapement unit the right way up, this shows the the whole lot held together for the camera.  Hope it makes sense. (Must clean away the flux residue.)

 

post-8139-0-07725100-1495836246_thumb.jpg

 

Having enough of Howard's components, the point rodding can be added and could be made to work right back to the signal box, driven by the switch drive (but there lies madness!).  I shall be content just to have the pictured parts operational.

 

(Oops! I realise now that the crucial link  on the escapement unit which connects to the pivot is missing in the second photo.  Will try harder tomorrow  and post a shot of the complete unit.)

Edited by Colin parks
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Great stuff Colin, how do you aquire the Howard Bolton etches,please.

Hi Siberian Snooper,

 

Howard's etches are featured on his website, but it would be best to use the contact details there to get an idea of availability.  These etches are not cheap, but unlike many other pointwork/rodding etches, they are etched in nickel silver, making them quite a lot stronger than brass parts of the same size.  I have enough parts for the above-board scale rodding and also the etched cranks and guides of larger size for mechanical operation from underneath the board. (That is still a long way off!)

 

Colin  

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As you say not cheap, but definitely quality. I just need to source some decent stretcher bars now, I have tried the Ambis ones, although not bad, I found them to be a pig (polite mode on) to solder.

 

Edit for predictive text. More swearing.

Edited by Siberian Snooper
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As you say not cheap, but definitely quality. I just need to source some decent stretcher bars now, I have tried the Ambis ones, although not bad, I found them to be a pig (polite mode on) to solder.

 

Edit for predictive text. More swearing. of 

I am using 0.4mm glass epoxy laminate (GEL) for my stretcher bars on the recommendation of Howard Bolton.  The home-made stretcher bar brackets are going to be fixed to the bars with Loctite 435 (think that is the right number).  I am going to make a jig to hold the brackets in position for soldering to the switches.  

 

Using GEL stretcher bars and the etched components will be something of an experiment, because Howard's method* has only been used (to my knowledge) on bullhead rail which is more flexible than flat bottom rail, though being P4, the switches do not have to move very far!

 

* Will try to add the numbers of the Scalefour News journals in which this is discussed by Howard. (He uses Ambis stretcher bar brackets by the way.)

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