Jump to content
 

Tandem Queries & Scissors slip-up


Ian Smeeton
 Share

Recommended Posts

Hi Ian,

 

Here is an overview of one of my tandems, which might give you an idea of where the gaps should go.

 

post-25077-0-71957100-1531341822.jpg

 

The two crossings nearest the toe always have the same polarity, so there is no break between them.   Their polarity is switched by the first turnout.  The third crossing has its polarity switched by the second turnout, but one feed to that switch comes from the other two switches.  I think I have a wiring diagram somewhere so I'll try and dig it out.

 

As to building it, from memory I laid the two outer stock rails first, then the furthest out crossing and worked my way into the centre and towards the toe from there, using button gauges to set the position of the tips of the point rails on each crossing.

 

HTH,

 

Jim

Link to post
Share on other sites

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.

 

attachicon.gif2018_0329Workshop0001.JPG

 

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'.

 

attachicon.gif2018_0329Workshop0002.JPG

 

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

 

 

Ian

 

Yet again late with a reply, like you I find it so much easier to both cut and fill timbers before soldering any rails to the copperclad strips, its in my opinion quicker, looks better and finds faults which are much easier to trace, best of all you can check the build as you go with a loco under power. You can remove the plan easily as the tape is only in thin strips (3 or 4 mm wide)

 

I always cut the gaps with a junior hacksaw, as I found cuts with a razor saw allowed filings to short across the gap. Rather than using glue I cut thin strips of double sided tape and lay in strips either side of the rails at the end of the timbers. I cut the timbers with a junior hacksaw and place them on the plan . Then I mark the cuts with a felt tip. Each timber is taken off the plan and then gaped with a junior hacksaw ( no deep gouges with a slitting disc)and put them back on the plan again. Next checked with a multi meter, then filled with filler and then sanded once fully set. Sounds very long winded but is so easy to do, and saves awkward filling/sanding and fault finding at a latter stage

  • Like 1
Link to post
Share on other sites

  • RMweb Premium

I have been gapping timbers for the pointwork in Underwood Yard, Inc the tandem.

 

I thought that I would try a new Stanley Knife blade, but reverted to the razor saw, all done now, but I will remember the Hacksaw blade tip for next time.

 

Izzy of this parish, has sent through a JPEG of the tandem witha full set of timbers, and more importantly, the rail gaps, so I really should get a move on.

 

04. silly o'clock starts and a shopping trip this afternoon mean that the mojo is in rettreat tonight, and I have a builder coming to do some repairs tomorrow, so it may be a day or two before I get a move on.

 

Thanks, once again, for all the tips and pointers.

 

As per  a PM conversation, give track building a go, it ain't that hard, even I can do it.

 

Regards

 

Ian

Link to post
Share on other sites

  • RMweb Premium

Hi Ian,

 

Here is a copy of your turnout which I have generated in Templot - make tandem - with the middle crossing included and the timbers shoved, and isolation cuts marked along with a wiring dia. The latter bits being added by import/export through Photoshop so it's a jpg file rather than PDF, but should print out to the same size. I hope it will be of use to you.

 

post-12706-0-81394100-1531470085_thumb.jpg

 

details;  Ram  Middle crossing 1: 4.34  Left crossing 1:7  Right crossing 1:5.99.

             Curvature  LH 33.2"  RH 24.4"

             Both switches 'A' blades.

 

I have watched your track construction thread with interest and admiration, not giving up and getting them just right, and did rather wonder when I did the Templot file whether I was actually teaching my grandmother to suck eggs......   I feel certain showing what you are doing is encouraging others to have a go.

 

regards

 

Izzy

Edited by Izzy
  • Like 3
Link to post
Share on other sites

  • RMweb Premium

Many thanks for transferring the above, Izzy.

 

It would have taken me ages to get it looking like that in Templot.

 

Can I be cheeky and ask what angle you got for the middle crossing vee assembly?

 

Also, would the Crossing Timbers at C be left that long or would the 'outlet' track have reverted to standard sleepers at that point? (Pardon the pun)

 

Regards

 

Ian

Link to post
Share on other sites

  • RMweb Gold

Many thanks for transferring the above, Izzy.

 

It would have taken me ages to get it looking like that in Templot.

 

Can I be cheeky and ask what angle you got for the middle crossing vee assembly?

 

Also, would the Crossing Timbers at C be left that long or would the 'outlet' track have reverted to standard sleepers at that point? (Pardon the pun)

 

Regards

 

Ian

 

If I was doing it I would probably cut the lat two shorter and use standard sleepers of the top diverging route. I bet you could find all possible variations.

 

Don

Link to post
Share on other sites

  • RMweb Premium

Hi Ian,

 

As I used A7 for the base template to generate the 3-way, to match your original template, I would have thought it to be about 1-3.5 curviform, and measuring a printed copy appears to confirm that it's roughly that angle. I'm afraid I never think much about this aspect because I only ever used simple card jigs to generate V's. One aspect perhaps worth mentioning is that there will be the need to trim the inner ( top as it is currently viewed) wing rail of this crossing to provide check-rail sized flange clearance for wheels.

 

Because long timbers were expensive companies didn't use any more than was necessary, so as soon as standard size/length/width timbers could be used, they were, commensurate with the rail support needed.  As Don has said, whatever you feel is best and looks okay will probably be right.

 

Looking forward to seeing it being constructed.

 

Izzy

Link to post
Share on other sites

  • RMweb Premium

Sunday, at the earliest, as I am working a bar for 12 hours tomorrow.

 

Still to fill the crossing timber gaps, and 5 pints down after dealing with my builder (exceptionally reasonable apart from the forced beer consumption), so nothing will be done tonight.

 

I am not as thunk as dreeple pink I am,

 

Or am I?

 

Regards

 

Ian

Link to post
Share on other sites

Because long timbers were expensive companies didn't use any more than was necessary, so as soon as standard size/length/width timbers could be used, they were, commensurate with the rail support needed.

 

 

It wasn't so much that long timbers were disproportionately expensive but that wider ones were. As rails diverge through point & crossing work they cross nominally orthogonal timbers at increasingly obtuse angles and therefore the supporting chairs are also at increasing angles. In the early days of railways when chairs with two hole fixings were the norm this wasn't a huge problem, but as locomotives (in particular) became heavier and chairs with four hole fixings became necessary, sleepers supporting rails which weren't orthogonal necessarily became wider (12") and wider (14") to allow the chairs to be fixed satisfactorily. Some smaller railways seem to have actually continued to use two-hole chairs in such circumstances to keep the cost of sleepering within bounds but that wasn't a very good solution given that lighter chairs were being used at the very place where stresses were greatest. The use of three hole chairs reduced the problem to some extent which is why this type of chair eventually became commonplace (although they had other advantages too). However, quite a number of railways made a practice of using individual sleepers through p&c, the LNWR was probably the most senior of these.

Link to post
Share on other sites

Hi Ian,

 

Here is a copy of your turnout which I have generated in Templot - make tandem - with the middle crossing included and the timbers shoved, and isolation cuts marked along with a wiring dia. The latter bits being added by import/export through Photoshop so it's a jpg file rather than PDF, but should print out to the same size. I hope it will be of use to you.

Thanks for posting that Izzy.  I've been busy the last few evenings, so haven't had time to search for the drawing I have.

 

Jim

Link to post
Share on other sites

Hi Ian,

 

As I used A7 for the base template to generate the 3-way, to match your original template, I would have thought it to be about 1-3.5 curviform, and measuring a printed copy appears to confirm that it's roughly that angle. I'm afraid I never think much about this aspect because I only ever used simple card jigs to generate V's. One aspect perhaps worth mentioning is that there will be the need to trim the inner ( top as it is currently viewed) wing rail of this crossing to provide check-rail sized flange clearance for wheels.

 

Because long timbers were expensive companies didn't use any more than was necessary, so as soon as standard size/length/width timbers could be used, they were, commensurate with the rail support needed.  As Don has said, whatever you feel is best and looks okay will probably be right.

 

Looking forward to seeing it being constructed.

 

Izzy

 

 

Izzy

 

Timbers are a minefield as from what I have seen and read about the maximum length not only varied between companies but even between different depots within the same companies, I guess in someways it was what was available, then also some spliced timbers together to create longer lengths. As you have said its all about what looks right, unless you have evidence to the contrary. In my opinion the hardest part is deciding where you transition from timbers to sleepers

Link to post
Share on other sites

  • RMweb Premium

Ian,

 

Just a few bits regarding the drawing. The 'make' 3-ways  option in templot uses, I believe, 7 partial templates (It's very clever stuff ), and so the two checkrails in the top of this shot would I think probably just be one covering the length. I have circled the wing rail that will need trimming for the same reason.

 

post-12706-0-13219700-1531569493.jpg

 

I would suggest you also check the toe of the blade clearance on switch 2. I have re-drawn this open just to see, and it's looks okay, but having had problems recently with this aspect in a single-slip it is I feel worth making sure. I use a 1mm gap here - at the switch toes -  and as my under-turnout tie-bar system uses 0.5mm brass wire soldered to the blades I find the gap between the stock and closure rails needs to be at least 2mm to give enough movement room. This is why I generated it using an A7 as the base template, to give the greatest possible deflection and widest distance between the rails here.

 

post-12706-0-93504600-1531569504.jpg

 

regards,

 

Izzy

Link to post
Share on other sites

  • RMweb Premium

 Just thought I would add the details of the template I posted, which are in the templot dialog as it's generated. I just clicked and didn't look as properly as I should have. These bring up the fact that the crossing angles all vary, the two diverging routes don't have the same one, which I assumed they did. I will also add these details to my post with the template, for general information.

 

 So;  Ram  Middle crossing 1: 4.34  Left crossing 1:7  Right crossing 1:5.99.

        Curvature  LH 33.2"  RH 24.4" 

 

Both switches 'A' blades.

 

Izzy

Link to post
Share on other sites

  • RMweb Premium

Plumbimg suspended due to a missing straight pipe joint. I was so sure that I had one in stock, that I didn't pick up a spare.

 

No more excuses, on with the tandem.

 

 

I had prefabricated a load of 1:6 and 1:7 crossings, and then used most of them.

 

The Templot template was based on a LH 1: 7 and a RH 1: 6, fortunately, I had sufficient left for this job, but I foresee an afternoon spent fabricating another 5 or 6 1:7s so tthat I can complete the points in Underwood Yard. We will have to see how I get on with the tandemm, though.

 

post-89-0-86460100-1531653899_thumb.jpg

 

A bit hit and miss, here, the crossings were placed on the template, but there was only room for a single roller guage.

 

post-89-0-05022600-1531654148_thumb.jpg

 

First solder joint was heartstopping, praying that nothing moved.

 

Everything seems OK at the moment. It is scorching hot in the garage, so I have abandoned ship for now.

 

Thanks for everyone's advice so far.

 

Regards

 

Ian

  • Like 1
Link to post
Share on other sites

  • RMweb Gold

Plumbimg suspended due to a missing straight pipe joint. I was so sure that I had one in stock, that I didn't pick up a spare.

 

No more excuses, on with the tandem.

 

 

I had prefabricated a load of 1:6 and 1:7 crossings, and then used most of them.

 

The Templot template was based on a LH 1: 7 and a RH 1: 6, fortunately, I had sufficient left for this job, but I foresee an afternoon spent fabricating another 5 or 6 1:7s so tthat I can complete the points in Underwood Yard. We will have to see how I get on with the tandemm, though.

 

attachicon.gif2018_0623GranthamSteamFair2010002.JPG

 

A bit hit and miss, here, the crossings were placed on the template, but there was only room for a single roller guage.

 

attachicon.gif2018_0623GranthamSteamFair2010003.JPG

 

First solder joint was heartstopping, praying that nothing moved.

 

Everything seems OK at the moment. It is scorching hot in the garage, so I have abandoned ship for now.

 

Thanks for everyone's advice so far.

 

Regards

 

Ian

 

 

It may be a due to the camera angle but that lower crossing  doesn't seem to follow the line on the templot plan. I suspect this is because the curve of the closure rail runs through the crossing whereas yours looks straight. It would not matter if there is sufficient space to curve the rail enough to fit the middle crossing in, so I suggest just doing a check before proceeding. Very tricky tandems as the three crossings have to match up.

 

Don

Link to post
Share on other sites

  • RMweb Premium

You are quite correct, Don.

 

They had only been part soldered in place, and now, with some additional solder blobs, are in the correct alignment.

 

More photos to follow when the solder solidifies later today.

 

I have abandoned the shed for the evening, as with low level sunshine falling across the working area, along with stored heat, it was getting rather uncomfortable in there.

 

Even filing and soldering common crossings outside for the rest of the points was abandoned, as my neck is now redder than most mid-west Americans!

 

Regards

 

Ian

  • Like 1
Link to post
Share on other sites

  • RMweb Premium

Having bought a tandem a couple of years ago, which SWMBO refuses to ride, where can I get a T shirt which says on the back

 

"If you can read this, the b*tch has fallen off"

 

More on topic is where next?

 

post-89-0-01682000-1531907860_thumb.jpg

 

I have soldered the common crossings 1 & 2 in place, nice and parallell

 

I was thinking of starting with the upper switch blade, followed by the upper curved rail as far as the end of the set.

 

Do the assembled company have any good advice (apart from Googling the T shirt, already done & ordered).

 

Regards

 

Ian

PS too long since I learned how to spell paralellell

Edited by Ian Smeeton
Link to post
Share on other sites

My approach to turnout building was different from yours, Ian, in that I didn't pre-assemble the crossings, but built them in situ. I laid the stock rails first, then used button gauges to locate the tip of the point rail. It's a good number of years since I built the tandems, so I can't recall in detail how I did them, but I think I followed the same principal, laying the outer stock rails first, then working my way in from them. Not much help then, I'm afraid.

 

Jim

Link to post
Share on other sites

  • RMweb Premium

Not to be outdone by the above post, I started to do a little more soldering on the main board, with the yard throat leading to Underwood Yard and the Abercorn Oil Works.

 

Out with the fibreglass scratch brush, flux, iron, solder & some recently arrived rail to start the last full set of points between the Scissors & Underwood Yard.

 

post-89-0-89444500-1531910881_thumb.jpg

 

The topmost right set, to be precise.

 

However

 

post-89-0-08761200-1531910976_thumb.jpg

 

I did wonder at the time of construction, why I needed longer switch rails than I had already filed up.

 

The answer was staring me in the face.

 

I had misread the Templot drawing, and had extended the switch rails to the toe of the points leading to Abercorn Oil Works.

 

Silly ****** ( I shan't use the word which has caused a certain Duck lots of Grief)

 

I REFUSE point blank to lift the scissors & start again, so.....

 

Shoudk I a) cut back the whole toe section of the scissors assembly and rebuild, or

 

b) use A sized switches on the Oil Works poits to gain a few mm, and just 'Bodge' it?

 

Comments?

 

Regards

 

Ian

 

 

Link to post
Share on other sites

  • RMweb Gold

 Assuming you do not want to move the turnout along and wish to retain the angle and position of the diverging route, I would first check that the scissors works fine and things run nicely though it. If that is so then cutting back the toe section of the scissors would not be my choice.  You are then left with two options;

 

1. Decide where you could place the blade tips  then measure the distance from there to the crossing nose. This is the lead. The crossing angle is already fixed so I would look up in a table to see what the lead for an A6 or whatever the crossing angle may be if it is less than you have measured  then you know it will fit.

 

2. As above decide where the tips could go then file up the blade to fit the situation. The danger is it might be unacceptably sharp.

 

It is an odd fact that the closure rail radius of an A6 is  greater than that of a B6 this is due to the fact that as the switch blade of a B switch is gentler it will have turned less of the required angle by the heel point. The closure rail  then has to turn more in less width than the A  switch has to turn so needs to be a tighter radius.   You may also find that a straight switch either a 9ft or 12ft  may be shorter. The difference between an A and B switch is important ful size as the switch acts as a transistion curve and the B is gentler. This is less important in our models but you may notice the bogie of a loco swng out further on an A switch as it enters the curve.

 

A quick check with Templot A6  min rad 573mm  lead  99.5mm

                                            B6  min rad 553mm lead  110.9mm

                                    9ft 1:6    min rad 593mm lead   98.7 mm

 

Looking at that I dont think about 11mm will be enough. So you may have to move the crossing of the diverging route along or use a sharper crossing

 

I did provide a table of leads in an article in the 2mm Mag on curved turnouts. However I can look up some for you. quick check on Templot instead.

 

A5.5  min rad  467 lead 95.6

A5     min rad  376 lead 91.6

9ft 1:5.5  min rad 498 lead 93.7   

 

Doesn't look to hopeful to me.

 

Hope this helps

 

Don

Edited by Donw
Link to post
Share on other sites

  • RMweb Premium

attachicon.gifTndemToubles.jpg

 

I have soldered the common crossings 1 & 2 in place, nice and parallell

 

I was thinking of starting with the upper switch blade, followed by the upper curved rail as far as the end of the set.

 

Do the assembled company have any good advice (apart from Googling the T shirt, already done & ordered).

 

Regards

 

Ian

PS too long since I learned how to spell paralellell

 

Everyone I think seems to build things up differently, and so long as it works in the end that's all that really matters. Personally I have to say that I would complete the middle crossing next, as I always prefer to work from the crossings out on the basis that if they are centered where they should be then the other rails can be adjusted to fit. Then I would use middle and ** 1 to gauge/lay the lower stock rail followed by the lower blades on both routes, (checking the blade movement clearance at this stage as the upper closure rail could be adjusted to suit - which would of course affect the actual position of it's matching stock rail), so they could all be used to set the middle closure and upper stock rails since these will probably be the easiest to finesse to fit.

 

Izzy

 

**edited to correct crossing No from 2 to 1 **  - sorry

Edited by Izzy
Link to post
Share on other sites

  • RMweb Premium

Thannks for the above, Gents.

 

It will be the weekend before I can look at both problems properly.

 

I suspect that I will move the point in question about 10 mm as the scissors has already been through three full rebuilds so far and it seems to work as built.

 

Sadly, I am only at the 'push along' stage, as no electrons have yet been emplyed in this build, and as yet I have no 2mm fs locos, only 4 coaches and three wagons plus 2 2mm wagon chassis

 

Sometimes I think Brio might have been a better option!

 

 

 

Regards

 

Ian

Link to post
Share on other sites

  • 2 weeks later...
  • RMweb Premium

Everyone I think seems to build things up differently, and so long as it works in the end that's all that really matters. Personally I have to say that I would complete the middle crossing next, as I always prefer to work from the crossings out on the basis that if they are centered where they should be then the other rails can be adjusted to fit. Then I would use middle and ** 1 to gauge/lay the lower stock rail followed by the lower blades on both routes, (checking the blade movement clearance at this stage as the upper closure rail could be adjusted to suit - which would of course affect the actual position of it's matching stock rail), so they could all be used to set the middle closure and upper stock rails since these will probably be the easiest to finesse to fit.

 

Izzy

 

**edited to correct crossing No from 2 to 1 **  - sorry

 

I was thinking along the same lines (pun intended). Most of the way, anyway.

 

post-89-0-51839300-1532807616_thumb.jpg

 

Middle crossing followed 1 & 2,

 

post-89-0-56600900-1532807761_thumb.jpg

 

Then the closure rail from the Upper route, as it diverges first. The running rail at the bottom was soldered as far as the set/blade tips mark so that I had something to work against, before the closure rail was added.

 

Then the upper diverging rail was gauged from the closure rail/crossing.

 

Next, the 'Middle Road' upper closure rail was soldered in, clipped at the blade end with a filed bulldog clip and braced against a piece of brass strip to keep it straight.

 

Then the closure rail for the lower diverging route and the curved rail at the bottom gauged off that. Finally the last straight closure rail was added.

 

post-89-0-88438500-1532808431_thumb.jpg

 

Check rails and tou's still have to be added, however a wagon negotiates all routes with ease and without derailment.

 

It has taken a long time pondering the order of service, but by building out from the common crossings (1 & 2) seems to have worked for me.

 

Just as well that I have had a lot of thinking time at work. Doing one of the most boring jobs on this earth does have some benefits!

 

Regards

 

 

And thanks again, all, for all the input.

 

Ian

 

Edited to change wogon to wagon......not sure what brand of alien a wogon is?

Edited by Ian Smeeton
  • Like 1
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...