Layout Fiddleyard Planning - 4ft radius turnout

Tell us about your layout, where you put it, how you built it, how you operate it.
Alan Turner
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Re: Layout Fiddleyard Planning - 4ft radius turnout

Postby Alan Turner » Fri May 22, 2020 7:40 am

Rather than using kitchen draw slides you might care to have a look at something like this: https://www.ebay.co.uk/i/132644534766?c ... gJ_hvD_BwE

Far higher precision and almost the same price!

regards

Alan

Terry Bendall
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Re: Layout Fiddleyard Planning - 4ft radius turnout

Postby Terry Bendall » Fri May 22, 2020 4:06 pm

Guy Rixon wrote:I don't see why anybody would need to mechanise a fiddle-yard traverser. Why not just slide it by hand


Very true. What I have done can be seen at https://www.scalefour.org/scalefournort ... ad-06.html . The traverser runs on aluminium vee pulleys which run on the edge of two lengths of 40 mm x 6 mm aluminium angle. Moved by hand with location by a 3mm square sliding bolt. Final alignment made using a MK 1 eyeball. Lots of slop but it works and that will do for me. The same traverser is used on Longcarse West.

The KISS principle is useful to bear in mind.

Terry Bendall

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David Thorpe
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Re: Layout Fiddleyard Planning - 4ft radius turnout

Postby David Thorpe » Fri May 22, 2020 6:21 pm

I don't know why there's all this suggestion that drawer runners = slop. I recently built a 7-road 110cm long traverser using a whole lot of spare timber and a couple of heavy-duty 24" drawer runners that I bought from Amazon. In fact, they were perhaps a little longer than I needed. I did make sure that they were parallel when i built the traverser, and I can assure you that there is minimal if any slop. I slide the traverser by hand - it is extremely smooth - and line up the tracks with home-made "bolts" using brass tube and rod. Being DCC, electrics are very simple. One factor I think is important is that the traverser itself is on a board 140cm long which means that the seven roads do not have to line up with a completely different board. A couple of pictures may show it more clearly. I've been very pleased with it and while I cannot claim it to be a thing of beauty it really does work faultlessly. To save me building track for the traverser I used SMP.

traverser1.jpg
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traverser2.jpg
traverser2.jpg (309.13 KiB) Viewed 970 times

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Guy Rixon
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Re: Layout Fiddleyard Planning - 4ft radius turnout

Postby Guy Rixon » Sat May 23, 2020 9:29 am

David T.'s traverser has two great virtues that reduce the need for precision parts. First, any tendency for the table to crab is taken out by the operator's eyes and wrists (highly refined: 100,000's of generations of development!), not by the mechanism. Second, the fine alignment of table with exit track can be fixed by the bolts if the table runners don't get it quite right. I contend that the drawer runners under this table are relatively sloppy but the overall design makes the assembly precise enough. This is a very good approach.

Relying on a mechanism to get alignments right in all six degrees of freedom to fairly high accuracy ... is possible, but it's hard. It's the sort of thing you only do when an operator can't be there. In my professional life, these kinds of mechanised slides were used when the operator would have been 15m off the ground, upside down in the dark, and strapped to a telescope frame (and probably on the 'phone to his union about better pay and conditions). The assemblies were designed by specialist engineers, made by craftsmen in proper metal using decent tools and they were still potent sources of grief. The users greatly preferred the instruments where the slides were set by hand.

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David Thorpe
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Re: Layout Fiddleyard Planning - 4ft radius turnout

Postby David Thorpe » Sat May 23, 2020 12:52 pm

Guy Rixon wrote:David T.'s traverser has two great virtues that reduce the need for precision parts. First, any tendency for the table to crab is taken out by the operator's eyes and wrists (highly refined: 100,000's of generations of development!), not by the mechanism. Second, the fine alignment of table with exit track can be fixed by the bolts if the table runners don't get it quite right. I contend that the drawer runners under this table are relatively sloppy but the overall design makes the assembly precise enough. This is a very good approach.


Thanks, Guy. In fact, however,there is no crabbing movement whatever in the traverser, nor any slop. I'll attach a photo below, but basically the two drawer runners are fixed on timbers running across the traverser framework and then a length of timber screwed onto the runners - the photo shows one runner as fixed, the other (left hand one) also fixed but with the timber screwed on top of it. The traverser table is then screwed onto the two lengths of timber. That provides a completely rigid table with no crabbing although there is of course full movement forward and back. As for the bolt, I've also attached a photo of it - one bolt, but with a separate barrel for each track into which the bolt slides - crude but effective. The barrels (I don't know what bthe proper name is for them) were glued in place after the track and main bolt were fitted. and so could be adjusted if necessary. I did put some copper clad sleepers at the end of the tracks which I would have soldered in place had there been any movement, but there hasn't been.

traverser3.jpg
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bolt.jpg
bolt.jpg (342 KiB) Viewed 858 times

Julian Roberts
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Re: Layout Fiddleyard Planning - 4ft radius turnout

Postby Julian Roberts » Sat May 23, 2020 2:04 pm

Just to revert back to the trackwork alternative. As Keith pointed out, a Y point saves a lot of space for the same radii. I've managed to get this far on Templot, a Y with 48 inch radius, each way I hope. Somehow the grid is only showing 150mm, but thats all that matters, the distance blade tip to V. The crossing angle has become 1 in 4.

Next to try to draw in return to parallel tracks. And then see if I can make it 3 way.

I may have forgotten to say the previous real turnout has shallow enough curves that I can propel 57 ft coaches through without buffer locking, and there is clearance between them 300mm from the blade tips. At the main line end of my proposed layout there will be no need to propel vehicles so it is that end I am thinking of for this Y I am drawing.
Attachments
12 inch radius Y point.PNG

Winander
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Re: Layout Fiddleyard Planning - 4ft radius turnout

Postby Winander » Sat May 23, 2020 2:30 pm

Julian,

You can set the minimum radius somewhere in the menus or on the pop up panel (f1 or f2) when the turnout is the control template. This will tell you if any part of the turnout is below your set minimum.

HH
Richard Hodgson

Julian Roberts
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Re: Layout Fiddleyard Planning - 4ft radius turnout

Postby Julian Roberts » Sat May 23, 2020 3:02 pm

Hi Richard thanks yes I saw that. The problem is doing it on both roads. In fact it seems that the type of Y turnouts we modellers have in mind are problematic as, while very useful for us in fiddleyards, (if I understand correctly) they are unprototypical so not really particularly in the mindset of Templot - which in a way is great as we're being steered all the time towards the prototype not modelling clichés. But for a fiddleyard I need a modelling cliché - perhaps Guy's idea of scaling up a Peco template would be an idea.

So one can set the minimum radius for the turnout road, but the main route was straight, and I bent it using the F6 key and mouse, and it shows what the radius is being changed to as you bend it.

[ Edit as you bend the main route, the turnout route flattens. Having got the main route to 1219mm I reduced the crossing angle till the minimum radius warning was showing less than 1219 then adjusted till it wasn't. Probably this is totally naff way of doing it. I've added screenshot below that includes the information. This was a repeat effort. ]

These are the blundering steps of a novice of only a few hours Templot addiction! - so probably I shouldn't be saying anything. Attempts to get a return track so far have been failures.

However yesterday I managed to get the first turnout on the map background - a very long curved one, a 1:18 angle with F switch!
Attachments
20200523_162605.jpg
Last edited by Julian Roberts on Sat May 23, 2020 6:08 pm, edited 2 times in total.

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Martin Wynne
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Re: Layout Fiddleyard Planning - 4ft radius turnout

Postby Martin Wynne » Sat May 23, 2020 4:04 pm

Hi Julian,

The best way to create a symmetrical Y-turnout in Templot is to use an irregular half-diamond template. Start with an ordinary half-diamond on the desired radius and adjust the K-crossing angle (F10) until you get the V-crossing on the centre-line of the approach track. Then shorten the approach track to make space, and use the peg on split deflection position to peg the turnout onto it.

For visible track (not needed for a fiddle yard) there is also an option to adjust the timbering to match a normal switch.

More info here: http://85a.co.uk/forum/view_topic.php?i ... forum_id=6


Image

cheers,

Martin.
40+ years developing Templot. And counting ...

Julian Roberts
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Re: Layout Fiddleyard Planning - 4ft radius turnout

Postby Julian Roberts » Sat May 23, 2020 5:04 pm

(I edited my previous post).

Martin thanks so much. As I'm a novice I imagine this may try your patience. When I convert turnout to half diamond the approach track vanishes so I don't know how to get the V onto the centre line of the approach track. Here's where I've got with radius fed in
Attachments
20200523_175330.jpg

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ianpenberth
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Re: Layout Fiddleyard Planning - 4ft radius turnout

Postby ianpenberth » Sat May 23, 2020 5:40 pm

Hi Julian,
Apologies if you've already looked at the link that Martin gave, but I was in exactly the same situation a couple of months back and found all the information I needed there.
I am a bit more experienced with Templot so might have been able to make conceptual links that you're not, but I think it's a full explanation.
Cheers.
Ian
PenBits Model Railways - Diesel bogie springing and detailing

Julian Roberts
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Re: Layout Fiddleyard Planning - 4ft radius turnout

Postby Julian Roberts » Sat May 23, 2020 6:16 pm

Hi Ian
Yes I see that I just need to get more accomplished at using Templot before asking more questions. Good to know such a expert as you were learning the same stuff only recently. Thanks for the thought :thumb

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ianpenberth
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Re: Layout Fiddleyard Planning - 4ft radius turnout

Postby ianpenberth » Sat May 23, 2020 6:29 pm

Hi Julian,
The trick is that you're using half of a switched diamond crossing to represent the turnout.
HTH
Ian
PenBits Model Railways - Diesel bogie springing and detailing

Julian Roberts
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Re: Layout Fiddleyard Planning - 4ft radius turnout

Postby Julian Roberts » Sat May 23, 2020 8:21 pm

Thanks for the hint Ian! Also thanks everyone for helpful ideas.


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