Train Line R2 points....cut'n'shut

[Brixham]

James, the owner of the now temporarily defunct Guano corner railway ( youtube search for LGB Guano ) has plans for version 3..a modified and upgraded version 2. One of the planned changes is to the branch shuttle, which will incorporate R2 points leading to a further station. So, a pair of T/L R2 points have been acquired, but the geometry doesn't match LGB's R2 curves.
So with a bit of cutting and shutting to an existing LGB R2 curve, the T/L point now almost matches the length and curvature of a standard LGB R2. After making two 'make up' pieces, with the remains of the R2, I made a half R2, and because of mismatch in sleeper spacing, a really useful 1/4 R2 half isolating curve....it's missing the isolator and a fishplate, as I can't find my spares!

Malcolm

 

[Gizzy]

I had the same problem with a T/L R2 point myself Malcolm.

It has a 22.5 degree arc to match up with T/L R3 curves and points, where as, LGB R2 (and R1) curves are 30 degree arc.

Like you, I made up a 'filler' piece from a cut down curve....

 

[Brixham]

Yes Gizzy, I remembered your post, but a search in track topics didn't show up trainline points.
LGB sell their R5 points with a half straight make up piece, perhaps T/L should have a make up piece included with their R2 points to make them up to 30 degrees. This would add perhaps another £5 to the cost. I can see why the points have a shorter curve, this is to reduce the track centres when used as a crossover, which looks like it will be 150mm. Off the top of my head, isn't 165mm the normal LGB track centres. With the R2 make up pices, the track centres come out at about 190mm. James has bought a left and a right hand, so the only way I can mock up a crossover is to have one point upside down!

Malcolm

 

[Gizzy]

Off the top of my head, isn't 165mm the normal LGB track centres?

Track centres of 165mm are correct for R1 and R2, but from R3 upwards the track centres change to 185mm Malcolm.

I can't find the geometry for T/L 45 points at the moment, but the track centres do change for R2/R2, R2/R3 and R3/R3 crossover configurations, and I seem to recall that it is indeed 150mm for the R2/R2. I believe this is a little too close personally, especially for curved double tracked R1/R2, because the overhang of passing trains could collide. I would therefore insert a short straight filler piece in a R2/R2 crossover to bring the centres to the LGB norm of 165mm.

In fact, I reckon on my double tracked LGB R1/R2 curved sections, the track centres are slightly wider at 170(ish) mm, and is something LGB have built in to give a little more wiggle room!

My experiences of the R2 point can be found here;

http://www.gscalecentral.net/The-Logging-Gravel-amp-Brickworks-Railway-m3792-p20

from post #338....

 

[James Day]

Malcolm,

You have done a great job. Much appreciated.

The earthworks in the rear garden are starting later today, so by the time those modified points 'come home' everything should be finsished ready for them to be installed as the layout is re-built. (Fingers crossed!).

I do take issue with the suggestion that they are 22 1/2 degrees though, they are more than that, as a simple experiment shows.....

Firstly we need to establish a 'universal truth' - Any radius 2 rail will be longer than the equivalent radius 1 rail! Thus an R2 full curve will be longer than an R1 full curve. The same rules would apply to R2 half curves and 1/4 Curves too, which would (if they existed) be proportionally longer than thier R1 versions.

Agreed?

Ok, so take a 7 1/2 degree R1 curve (a quarter curve) cat number 11040. Join this to the curved turnout portion of the Trainline R2 point. Then lay the whole assembly over an LGB R2 full curve. The branch on the point is already too long and has gone beyond the 30 degrees of the full curve. If I had a second radius quarter curve to join on instead, the assembly would be even longer, although the amount of turn would be the same.

From this experiment we can gather that the Trainline points live in a no-mans land, somewhere between 22 1/2 and thirty degrees. I am sure that someone with more skill/patience than me could measure the actual angle.

I am tempted to ask, what is the point of that? but that would be an awful pun, so I won't!

Yes, I do appeciate the concept of making a close crossover, but tend to feel that I would rather have to pay more to have the small curved make up piece included, (since it is a special item), that have to cut up a a perfectly good rail to make it up!

James

 

[Gizzy]

The problem here James is that the Train-Line 45 R2 is not the same as the LGB R2 curve.

The LGB R2 curve is 778 mm radius (an LGB 15000 R2 curve has a 30 degree arc, 12 to a circle) as can be seen here,

http://www.google.co.uk/imgres?hl=e...w=126&start=0&ndsp=14&ved=1t:429,r:2,s:0,i:86

T-L 45 R2 is 90 cm (900mm) and 22,5 degrees (16 to a circle), as described here,

http://translate.google.co.uk/trans...&sa=X&ei=FyQ3UYCMNoeUOO_JgdgH&ved=0CEIQ7gEwAA

In other words a whole +2 cm difference in radius, but a 'close enough' tolerance to use with LGB R2 curves. It has worked for me as you can see in my photo of post #2. Previously, I'd used a R1 point and some flexi track here, but it didn't quite look right as it wasn't anywhere near to parallel.

However, over-laying a LGB 15000 R2 curve on a T-L point and a LGB 11040 1/4 curve as you have done, will give erroneous results due to that +2 cm difference in radius....

 

[James Day]

Gizzy,

That is a brilliant reply. Much appreciated. I stand 100% corrected

The linmks were highly informative too. Never knew they made all that stuff.

Now I realise exactly why the Train Line points don't match R2 - They are not supposed to.

I am hopeful that Malcolm's surgery will make the points fit, as the images at the top of this thread suggest that they will, but the proof of the pudding will be in the actual installation.

Today the Tonka Toys were out in force on the lawn and we now have what looks like a much shelled 1916 trench system instead. They have done a lot in one day though. Bodes well for an early completion!

James

 

[Brixham]

I mocked up a quarter circle of R1 and R2, including the two t/l points. The spacing is 165mm, and the outer composite 'R2' curve is almost parallel with the inner R1. I suspect that if only 1 T/L R2 point with two normal LGB R2's were used, the tracks would be almost perfect. It's handy have carpet tiles with lines....this is at work of course....can't afford carpet at home as have LGB to buy!
Malcolm

 

[tram47]