Scalefour Forum

TonyMont wrote:I suppose I could lift a template off the Templot club site. I will have a go.

Hi Tony,

There is a downloadable Templot file for a scissors crossover at:

http://85a.co.uk/forum/view_topic.php?i ... forum_id=1

(It's EM and curved, but will serve the purpose.)

cheers,

Martin.

Martin your sketch is showing an undercut switch with the top of the tip at the gauging line 18/32" below rail top level with an effective width of zero. Hi Julian, My sketch was intended to show that IF the tip is reduced to zero width at the gauging depth, then the gauge is unaffected and no...

Was Martin talking about Straightcut switches? I thought he was trying to dissuade me from them and joggles. ... Hi Julian, I've lost track of what you were asking me. http://85a.co.uk/forum/images/emoticons/confused.gif The 9/16" gauging line below the rail top applies to all track, not only ...

That looks similar/identical? to the diagram further down on your link earlier Martin from a contributor Richard R. Hi Julian, They are actually from David Rayner: http://85a.co.uk/forum/view_topic.php?id=2802&forum_id=6#p19573 David runs "Off The Rails" for 3-D printed chairs, etc: h...

Dave (Bradwell) there are two gradients on the blade tip of your elevation drawing. How far below rail level is the tip of the blade on your drawing, how far is it till it is at full height and how far along does the first gradient end? Hi Julian, Here are some better quality scans. Bear in mind th...

Just to make the point that if we have gauge narrowing of say 0.1mm at the tip (because the thickness of a B switch blade can't be as little as 0.33 Hi Julian, There is no gauge narrowing (measured at the gauging line, 9/16" below the rail top). It is perfectly possible for the tip thickness t...

John Donnelly wrote:Templot plan is down with a couple of trains for effect

+1

The tip of the blade should be low enough that the wheel does not make contact with the top or inner face of it until it has passed some way beyond the toe of the switch blade. It then continues to rise to progressively take the full load of the wheel tread. Joggled switch blades take the full load...

Obviously in the model, to function as intended the height of the blade will need to be controlled, while the real thing is heavy enough not to stand proud of the slideplates. I soldered arms to the stretcher bars to go under the stockrails so the blades cannot rise Hi Julian, An essential function...

Hi Dave, Well I have this drawing of how to represent an undercut switch tip in simplified model form (assuming vertical rail): http://85a.co.uk/forum/gallery/2/original/2_212140_560000000.png Julian you asked if I have any suggestions for joggles, and the answer is yes -- don't use them . http://85...

If using a ruler the length between A and C will not abut the ruler. Hi Julian, Your drawing is correct. It is actually very tricky to get right in a model, especially the very slight bend needed at C. Phil wrote: If you're building GW turnouts, the timbering is square to the centreline, what Marti...

Hi Julian, In Templot you can: switch joggles on or off for any template; create a custom switch having any joggle dimensions of your choosing, or use one of the pre-set GWR switches based on prototype dimensions; select "overscale joggle depth" in the generator, which over-rides any other...

p.s. to clarify that diagram -- or make it more confusing -- I have added some rail outlines:


This shows how the blade tip fits into the joggle to align the running edge with the unjoggled part of the rail.

Martin.

I have to make a pair of joggled B switches with full height blades as in the straightcut blades pictures earlier on this thread. I can file the blades to a minimum sensible thickness of about 0.2mm. 3/8" blades scale out at 0.125mm. Hi Julian, You should be able to file them thinner than that...

The point kits no longer seem to be listed on the Exactoscale site which is disappointing as I was hoping the full range would become available again. I agree that the pricing under the last vendor was off-putting to say the least, but I do hope they re-appear (at a reasonable price for everyone). ...

Hi Julian, I'm wondering if pin-point axles play any part in this. Is there any empirical evidence on the relative derailability of wagons with pin-point versus parallel needle bearings? Note that the prototype doesn't use pin-point bearings. Nor traditional tinplate train sets. If there is any end-...

After laying out the sleepers on the Templot which had double sided tape on it I marked the points where the rivet needed to go. The pen I used, the ink bleed into the wood rather than leaving a a dot, so next time get a different pen. Went to use the hole punch and the pin didn't penetrate the sle...

The RAIB has published an accident report today which contains interesting information about the P1 wheel profile:

https://www.gov.uk/government/publicati ... ember-2018

Martin.

Martin's magic engine tells me that I have Vees to build soon in BH rail to these specs 1:x where x = 4.53, 5.08, 5.5, 5.58, 5.6, 5.7, 6.16, 6.25, 6.38 as well as the common values, 5, 5.5, 6, 6.5, 7 etc I have recently acquired a copy of "GWR Switch and Crossing Practice", which I have r...

Tim V wrote:I think you have to consider if you are representing what happened on one day, on say 12 September 1932

That would make an interesting model. It poured with rain all day.



Martin.

seanmcs wrote:I'd like to explore the GWR turnouts on Templot. Possibly would save me making up my own templates, as the printed ones are unsuitable. Can I look at it with a Mac?

Hi Sean,

Yes, there are 3 ways to run Templot on a Mac. Full details at:

http://templot.com/companion/for_you.php

cheers,

Martin.

"It is not widely appreciated that semi-curved switches came into use on the Great Western only in the 1930s and were used only for new construction. The older curved loose heeled switches remained in use into BR times." Hi Sean, The GWR did not use semi-curved switches. The flexible swit...

p.s. Dave, If it helps to understand what's happening in a joggle, I have added a red line to the diagram: http://85a.co.uk/forum/gallery/2/2_171738_320000000.png The red line shows the position of the stock rail for a plain set with no joggle. To make the joggle, imagine the stock rail being held a...

Martin , is the set the same where the stock rails have joggles ? Hi Dave, Yes, there is still a change in angle in the stock rail with a joggle. It's a slightly smaller angle than for a plain set because of the switch tip thickness. The object in all cases is to end up with the stock rail in the s...

The switch illustrated by Dave K causes me some concern, given the proximity of the tongue rail to the stock rail in the area I've indicated by a yellow ellipse Hi John, Dave, The photo illustrates well what happens when there is insufficient (or no) "set" in the diverging stock rail. Thi...