Tandem Queries & Scissors slip-up

[Mim]

Hope you can find a way of rescuing it. My experience of slug tape as a bus bar under the layout is that soldering heat destroys the adhesive locally under where the wire is attached. As a bus bar the good adhesive to each side keeps it all in place, but on something as small as a crossing timber this isn't likely. When pcb's are made the copper foil has surface treatments to promote adhesion to the resin in the substrate. Heat enough to delaminate it will have degraded the substrate and getting a good bond again is going to be difficult. Hot air desoldering has to be well controlled to prevent overheating as you have found. The flush brass rivet, or pin idea sounds a good bet for recovery maybe even a length of copper, or brass wire glued in to a drilled hole and filed down to the correct height. The length and area should give good adhesion and heat resistance

 

Mim

[Ian Morgan]

Have you tried removing a sleeper completely and replacing it? Desoldering braid or a 'solder sucker' may be required.

 

Ian.

[Ian Smeeton]

I had thought of removing the relevant timbers, however further work tonight has delaminated some more.

 

I may look at rescueing it with some new timbers, but I have already started on Mark 3.

 

Although quite a lot of work went into it, I don't feel too bad as the capital outlay is only about £3.00.

 

Try doing that with Peco Points!!

 

Regards, and thanks for all the sugestions.

 

Ian

[Velopeur]

How powerful is your soldering iron? Maybe you would be better using one with a lower wattage/temperature. My experience is that pcb only delaminates under excessive heat.

[Crosland]

Excessive heat is what you get from dwelling too long, waiting for the dolder to flow, because your iron is underpowered.

 

It's better to use a more powerful, but temperature controlled, iron to get in and out quickly, compared to a lower powered iron with no temperature control.

 

I never use anything less than a 50W iron, even for the most delicate surface mount electronics.

[Velopeur]

I am afraid I take the opposite view.

 

I have been using my faithful 12W iron for 2mm trackwork for at least 25-30 years with complete success. It can't cope with 4mm track, but for 2mm track it works perfectly for me.

 

I guess a lot depends on what you are used to.

[Ian Smeeton]

I think that the delamination problems were related to my (over) zealous use of the heat gun, as I could not liquify enough solder joints at a time to lift the relevant rails.

 

Two ways forward.

 

1 Chop the rail between each sleeper to minimise the dwell time. This does mean that rail cannot be reused.

 

2 When using the heat gun. Mask other areas with the foil and use brass strip/scrap etch (I now have quite a lot) as heat sinks close up to the areas being worked on.

 

Never mind, I have marked it all down to experience.

 

This is what I have been up to tonight.

 

 

New Tempplot plan printed, cut down to size and attached with Pritt Stick (OK cheapo equivalent)  to a suitable piece of flat scrap ply. First sleepers on the lead-in were laid last night, and clamped under a piece of flat timber to make sure that they are well stuck. Last pack of crossing timbers also in view. I shall have to re-order (again) soon.

 

This time, though, instead of laying the whole plan, I trimmed the pages back to the 'red' lines, so there is no overlap. I had not appreciated how much additional thicknesses of paper had affected the 'level'.

 

 

Some crossing timbers cut to length, and the rest of the 'lead-in'sleepers laid. 

 

Main 'bearers' under the Vees and K's of the diamond have also been added. Hidden under the clamped piece of timber unfortunately.

 

I am clamping each section as I go. Hopefully, this will help to keep the timbers in place when I come to cut the isolation breaks in them. fingers crossed.

 

Regards, and thanks for all the feedback

 

Ian

 

 

[Velopeur]

Ian, best of luck!

 

If you hit further problems, do bring your work along to one of our Thursday evening meetings at Laurie's Lair in Clayworth. I am sure that between us, we can give you a lot of help and advice. Unfortunately, the Sunday meetings currently all seem to be arranged on days when I am out rambling, so I can only do the evening meetings at the moment.

 

Richard

[Ian Smeeton]

Thanks for the offer.

 

Laurie's Lair is a very convivial affair on the Sundays. Thursdays are a problem for me as I often have a stupid o'clock start, often at oh four are you sure?

 

I have to say that I am thoroughly enjoying track and point building despite the setbacks.

 

Having built two of the beasts so far, I think that the third should come along nicely, especially now that I have a 1:7 jig and my own variable Vee jig for the awkward squad (1: 3.68 and 1:3.73 for the central diamond)

 

I would recommend Lauries gigs, as they are thoroughly enjoyable, and we have had, and are due to have some excellent speakers. Although it is a 2mm Area Group, I am sure that interlopers from other scales would be welcomed (especially if they bring cake!)

 

Regards

 

Ian

[Ian Smeeton]

A lack of  motivation over the weekend, a long list from the 'Boss', and filthy weather, to boot meant that not much was done.

 

A total mental block followed

 

I did contemplate the scissors for an hour or so, but ended up reading the 'Track' book from the 2mm FS Assoc.  Money very well spent IMHO, for any scale. I also spent some time re-reading this thread, and a few others about hand built track and turnouts.

 

It is odd how quickly the methods and tips disappear from trhe brain when you are not doing things on a regular basis.

 

Work, today. At least I still have a job, though it was looking doubtful last week. At least the threat being lifted slightly put me more in the mood for modelling. That and the fact that 8 hours running an injection moulding machine gave a lot of thinking time.

 

Going forwards.

 

 

 Attach the first Vee for the diamond. Not a full assembly, because this is one of the awkward ones, a 1 in 3.86 crossing.

 

Then attach the first obtuse crossing using roller gauge and brass strip (thank you, Eileen).

 

Finally, make up the first wing rail, solder in place using a panoply of dressmaking pins, map pins, blue tack and sheer bloody-mindedness to make sure the thing goes in the right place. Then trim the rail off two sleepers from the obtuse angle, and solder THAT in place, again using Anglo Saxon as the  best placeholder known to man.

 

This cut was made so that there is  an insulation gap. Guess who forgot last time?

 

 

The progress so far.

 

More to follow.

 

Regards

 

Ian

Edited for salutations

Edited April 9, 2018 by Ian Smeeton

[MikeTrice]

If you don't mind me commentingyou seem to be using quite a lot of solder for the joints which might be the reason removing sleepers/timbers later is an issue. I am NOT an expert on soldering but for N Gauge turnout contruction my soldering method seems to work well. It is described in the thread http://www.rmweb.co.uk/forum/viewtopic.php?f=8&t=42746 but you will need to scroll down so see it being done in detail.

 

When I have needed to remove a timber I prop the whole unit onto some card to act as a spacer but leaving a gap underneath the errant timber. Pushing down on the timber next to the joint with a needle file and applying the soldering iron you can feel the joint "pop". Repeat for the other side. I have even managed this with wing rails etc.

 

I have also tried using 0.6mm solder balls but prefer using the 0.3/0.5mm solder as shown, putting the solder on the iron then applying the loaded iron to the joint.

 

Personally I never find something goes right first time, and it might take a few turnouts to get there, but that is part of the learning curve so keep at it.

[Ian Smeeton]

Thanks for the suggestion.

 

Like you, my wife has often suggested that I need balls.

 

Perhaps both of you are right.

 

Touch wood, I have not yet had to remove a timber from this build. I did have to remove an errant rail though, and by chopping it off either side, bit, by bit, it was removerd without delaminating.

 

Patience, I am told, is a virtue, one of those things that I am sadly lacking (according to Mrs S)

Once again., many thanks for your intereset and suggestions.

 

Regards

 

Ian

[MikeTrice]

Touch wood, I have not yet had to remove a timber from this build. I did have to remove an errant rail though, and by chopping it off either side, bit, by bit, it was removerd without delaminating.

 

Patience, I am told, is a virtue, one of those things that I am sadly lacking (according to Mrs S)

However by working along one rail's joints in turn you effectively free up the rail. Now that I have had to do.

 

I lack patience as well so you are not alone.

[Ian Smeeton]

Finally completed.

 

I should have taken more 'through the builders' eye' photos, but I didn't.

 

However, Lessons learnt.

 

1: Start with the diamond in the centre.

 

2: First Vee, followed by the obtuse crossing, then the 'closure' rail linking them, keeping it all straight with brass strip.

 

3 Take your time!

 

4 2nd Vee, Obtuse crssing, and closure rail, gapping as you go, if necessary.

 

5 Hardest part, getting the two vee crossings for the points on the straight side first, to line up, approximately on the template.

 

6 Any mistakes, chop out the  offending rail, cutting into small pieces to aid removal without delaminating timbers.

 

7 Take your time!

 

 I have to say, that last night, when the end was in sight, I did get a bit of a move on. No regrets, though!

 

 

 

 

This has been the third attempt, and I am quite glad that it is over. All that remains to be done, is to arrange some form of tie-bar, and operating linkage. The jury is still out on method of operation, however it looks like 'Wire in Tube' is the favourite.

 

At least the cost (except in time) has been minimal. Having said that, I am still cursing the amount of materials needed, and the need to re-order.

 

Next on the agenda, is the main pointwork board for PSJ, so it will be back to that thread for furrther progress reports.

 

Then, I suppose, I had better think about the electrics. The lads in Laurie's Lair might be having their brains picked next time.

 

Regards, and thanks for all the help,

 

Ian

 

 

 

 

[nick_bastable]

that does look the dogs dangly bits how does it run  with  a gravity wagon ?   

 

Nick

[Ian Smeeton]

that does look the dogs dangly bits how does it run  with  a gravity wagon ?   

 

Nick

 

Very well indeed, and just as well with a gravity coach.

 

The lower right exit in the first photo will form the entrance to Underwood Yard. The next trick will be to combine the gravity wagon with others to alow loose shunting on the downgrade to Underwood

 

Watch this space, but don't hold yer breath.

 

Regards

 

Ian

[bécasse]

The one lesson that I would add - and others may disagree with me - is to start by soldiering each rail in as few places as are essential for actually fixing the rail in position, and only when you are certain that that is the right position, soldering the rail to all the remaining sleepers (doing a little bit here and a little bit there over a period of time to avoid heat build up and expansion problems). That way, if you do get something in not quite the right place, and we have all done it (more than a few times), it is easy to unsolder it and try again - or, indeed, to just ease it into the right place. That said, any complex piece of p&c is a potential nightmare and I reckon that scissors are actually almost the worst (but not quite as bad as a scissors with one or more double slips at the "corners" as was sometimes found on the prototype).

 

Hopefully, all's well that end's well!

[Donw]

Nice bit of work Ian. One thing I did find when building track using ply sleepers was that where I had epoxied down some chairplates (places where the plastic chairs wouldn't suit) | found that soldering the rail down would melt the epoxy but it would reset. As long as it was held in place by the timbers either side it was ok. I was thinking if you needed to replace the copper on a PCB sleeper expoxy might do the job for you.

 

Don

[Velopeur]

Ian, I feel the diamond in the middle of your formation should really have longer check rails so that the adjacent crossing noses are properly checked. If you compare what you have done with what you would normally see on a plain turnout, you will hopefully immediately realise the difference.

 

I have crudely drawn the missing bits below for the near end. I think the red extension is necessary, the yellow one more for tidiness. Should probably be the same at the far end of the diamond too, though maybe not quite as essential.

 

 

Otherwise, it looks a great piece of work. Well done.

[Ian Smeeton]

^^

 

Thanks for the input.

 

I may well go back and redo these, however, as this is a low speed line in a yard, I think I may be able to get away with it.

 

It is frightening what a cruel enlargement does to your sense of satisfaction. Mark III may well have to be replaced by Mark IV

 

Regards

 

Ian

[Caley Jim]

It is frightening what a cruel enlargement does to your sense of satisfaction. Mark III may well have to be replaced by Mark IV

Don't be too hard on yourself, Ian. If stock runs through it OK, leave well alone. I'm a great believer in 'if it ain't bust,don't fix it'. No need to get stressed out by a small cosmetic detail.

 

Jim

[Donw]

You can find various examples from a fully guarded crossing where the guardrails form an inner diamond,with the guards just for the obtuse crossings like Ian has done and also where there are four short guards one for each of the crossings the ones for the acute crossing being a small V at the mouth of the crossing. PLenty of choice then

 

Don

[Velopeur]

So much depends though on the position of the crossing nose relative to the diamond. On Ian's model, the left hand crossing noses are relatively close together, whereas the right hand two are noticeably further apart. Scissors crossings are often more symmetrical than that, so require a slightly different solution. The role of the checkrail is to keep the wheelset flange from hitting the end of the crossing nose, or even the wrong side of the crossing nose. It is more to do with function than appearance. For the LH lower crossing nose in particular, there just isn't enough checkrail to absolutely prevent the flangess from hitting the very end of the crossing nose, or going the wrong way. That is why I suggested he ought to make the checkrail marked in red a little longer.

[Izzy]

I believe extending the inner check rails will have no beneficial effect as they will not reach as far as the crossing nose if I am looking at the overhead shot Ian provided in post #65 correctly, and doing this could well introduce electrical isolation issues needing a re-working of where the rai/sleeper cuts are made i.e. as with a diamond like this both stock rails and check rails must be isolated from each other up until the cuts for the crossing unit itself. I fully agree with Jim, leave well alone unless running issues - hitting/riding up of the crossing nose - are encountered.

 

Izzy

[Ian Smeeton]

The focus has now moved towards Underwood Yard.

 

It didn't really have a tandem turnout, but I thought I would build one anyway,.

 

Mainly to save a little space, but also 'cos I just fancied one!

 

PSJ Tandem.box

 

I have extracted this from the main track plan

 

Would any kind soul like to give me any tips on building it? e.g order of construction.

 

A little early to ask, but what bout wiring and gapping it?

 

Regards

 

Ian