I'm working with an already built layout which has the main curves at each constructed using Peco set track and AFAIK 9" radius. I'm seeing some issues with my Roco Baldwin loco as it appears to slow a bit on the curves. I'm assuming this is because the radius is a bit tight for this loco, but what are my options? I have though about changing the centre drive wheels for flangeless but I don't think my skills are up to this so it would be expensive to have it done professionally. Another idea occurred to me to try and widen the gauge a bit on the curves by apply gentle heat and running the back-to-back gauge along it. The b2b is a tight fit even now.
Thoughts please and any other suggestions other than relay the track (!) which is really not happening ;)
That sounds odd, or I have misunderstood? I read it as if the back-to-back gauge feels tight between the inside faces of the rail head, which does not make sense to me. I would expect the gap between the back-to-back gauge and the rail head faces to be at least two wheel flange widths. Maybe we are using different terminology?
I have seen gauge widening on a layout with Peco track. The sleepers were cut, spread apart a bit and glued down I think. I imagine heating the plastic might be a bit uncontrollable.
Roco do not make a Baldwin in 009/H0e.
Is this a Bachmann 4-6-0 Baldwin, a kit built loco with a Roco chassis or another Roco H0e loco that is not a Baldwin?
It will help a lot to know what loco you are trying to use on your 9 inch curves.
A back to back gauge is for mesuring the distance between the wheels on a loco or item of rolling stock, it is not for mesuring the track gauge.
Again I think there is some confusion here as to what tool are you using?
To mesure the gap between the rails you should be using a track gauge not a back to back gauge.
Once we have sorted this out we should be able to help you a bit more.
If it's any help, I make my own track and back-to-back gauges, sometimes in plastic and sometimes in metal. The dimensions are different !
For gauge widening (rare), I usually cut the sleepers and re-glue using two-pack epoxy. Fill in the gap with ballast, or such like. It's a bit messy but seems to work. A millimetre here and there can make all the difference...
Regards,
Dave
Quote from: GraemeD on November 23, 2021, 17:23
That sounds odd, or I have misunderstood? I read it as if the back-to-back gauge feels tight between the inside faces of the rail head, which does not make sense to me. I would expect the gap between the back-to-back gauge and the rail head faces to be at least two wheel flange widths. Maybe we are using different terminology?
I have seen gauge widening on a layout with Peco track. The sleepers were cut, spread apart a bit and glued down I think. I imagine heating the plastic might be a bit uncontrollable.
OOPS! Sorry, I mis-spoke. I am using a track gauge not a b2b and it does seem tight on the curves.
Its a brand new 391-030 Bachmann OO9 Narrow Gauge Baldwin 10-12-D loco which is fine elsewhere on the track and even through the old Peco points, but it does slow noticeably on the curves. I have used the gentle heat treatment elsewhere with some success - I might try it on a bit that is behind the backscene and not ballasted.
Sorry for the confusion, old age & senility strikes
I have to say that perhaps you have the wrong loco for use on the set track 9 inch curves.
I have a layout with 9 inch curves and points and I only use 0-4-0's and small 0-6-0's on that layout.
Apart from any running issues the larger locos just look daft on the tight curves and many have coupling overhang issues as well.
If the points on your layout are electrofrog then they are 12 inch radius. If they have the dead plastic frogs then they are the 9 inch set track points.
If they are the larger radius points that would explain why the loco is fine in them but not on the curves.
I have to agree with Brian about the Bachmann Baldwin & 9" curves.
Bachmann have tried to solve an issue with this 4-6-0 loco (and one that the GEM white metal kit version suffers from) with the front pony truck arguing with the backs of the cylinders on curves. With the Gem kit one can carve away the backs of the cast metal cylinders or use the cast resin ones from RT Models sold as part of their valve gear upgrade kit to avoid the wheels on the pony truck touching the cylinders and shorting out the track current.
Instead of altering the shape of the cylinders Bachmann have 'split' the front pony truck to effectively turn the loco onto a 2-8-0 (though probably "2-2+6-0" might be a better description) so that front axle is on a 2 wheel pont truck the other set of carrying wheels are fixed as part of the main chassis followed by the driven coupled wheels. Tihs makes for a very long fixed wheelbase resulting in the binding (slowing down) on the curves.
I'm not sure how the Peco set track works in relation to gauge but certainly various flexitrack systems suffer from 'gauge narrowing' when bent to form curves (the rails tend to cant inwards more so that their heads are closer together than they should be). Part of the problem may be that if you are using a roller gauge then you'll be trying to fit 2 curved bits of metal into a pair of straight slots, so even if you tried the gauge on a singe rail it would be tight. A better way to check the gauge on these curves would be to try a '3-point track gauge', a triangular shaped device used by model railway track builders to lay curves that (if used correctly) automatically adds gauge widening on curves.
I'm not sure where you might source on in the UK as the ones I have (Micro Engineering die cast jobs) came from across the pond (made in the US but bought from Canada).
Another way to look at the issue is that a 9" curve scale up to one 58 feet in radius, and I suspect any loco driver would slow down to go around such a tight curve...
https://narrowgauge.retiarius.com/making-a-simple-3-point-track-gauge-for-peco-009-track/
I think 'engineering' tolerances must come into play here :
Looking at my wagons for instance there is quite a lot of side-to-side play in evidence. Locos, probably less so. My track gauge is 'stepped' going from approx. 8.5 to 9 to 9.5 mm.
Different sections of track see different traffic patterns, so, I try to mx and match accordingly. Admittedly, if you want to be able to run 'everything everywhere', some degree of compromise is needed. This is what the commercial boys are aiming for I'm sure.
Mine's only a working diorama however. On a larger layout, if I had long wheelbase vehicles then I would avoid tight radius curves /points like the plague. This may mean hand-building some of the points though. (Yet another modelling challenge I hope to be tackling soon !).