Has anyone tried the Minitrains small radius track yet? What sort of stock can manage those curves? (Minitrains' own assessment that the Brigadelok can manage them but will derail its cars is ... interesting.)
Inevitable I'd have thought, long overhangs and lack of coupling "swing" would lead to it pulling it's train off the track...
The radius is very tight around 6-7" I have never used the Minitrains track ( it actually seems expensive compared with Peco setrack which I don't use either!)
I would try to use as large a radius as possible subject to your space restraints, uness you are only using small 4 wheeled stock & short wheelbase locos with minimum overhang
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I think you will find the radius is 140mm/5.5ins.
CP
Quote from: cp.409067 on June 09, 2017, 14:23
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I think you will find the radius is 140mm/5.5ins.
CP
Hi Chris
I think I was being optimistic!! Never actually seen any MT track work in the flesh.
PS. I have followed your work over the years, very nice!!
Quote from: Steve Lewis on June 09, 2017, 12:05
I would try to use as large a radius as possible subject to your space restraints, uness you are only using small 4 wheeled stock & short wheelbase locos with minimum overhang
So the follow up question is: given the space restraints such that Peco 228mm/9" is out, but not so tight as to require going all the way down to the Minitrains 140mm, what's the minimum radius you can get to with flexitrack?
Carefully laid you should be able to get 7" radius, I have done about that in the past, if you have to make a joint on the curve it is best to 'stagger' the rail joints by 1/2" or so to prevent 'dog legs' occuring
Quote from: S Arrowsmith on June 10, 2017, 14:52
Quote from: Steve Lewis on June 09, 2017, 12:05
I would try to use as large a radius as possible subject to your space restraints, uness you are only using small 4 wheeled stock & short wheelbase locos with minimum overhang
So the follow up question is: given the space restraints such that Peco 228mm/9" is out, but not so tight as to require going all the way down to the Minitrains 140mm, what's the minimum radius you can get to with flexitrack?
I have quite happily used 4 inch curves on Green Pond Mine. It really depends on what type of stock you want to run. In this case it was 0-4-0 diesels, such as the Gmeinder or ND2F with small tipper wagons.
I have built a test track board with radii from 2 inch to 8 inch so that I can test using a loco and up to two wagons as travelling round sharp curves is dependent on the rolling stock be=hind the loco staying put on the rails through the curve. This is invaluable when testing out before building.
With regard to Peco OO9 Flexi-track, I follow James Hilton's advice in that I use a KB Scale rail bender to roll the curves into each rail and then reinsert them into the plastic track base. This gives curves the are consistent and stay curved. The alternative, which we did previously, was my wife to wrestle the track into place using oven gloves and then to solder it quickly to form 6 inch round track. This is not recommended for the faint hearted as she will attest! It worked though for her Teddy Bears' Picnic though.
Quote from: Steve Lewis on June 09, 2017, 17:04
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PS. I have followed your work over the years, very nice!!
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Steve
Thank you.
CP
Quote from: Steve Lewis on June 10, 2017, 15:00
Carefully laid you should be able to get 7" radius, I have done about that in the past, if you have to make a joint on the curve it is best to 'stagger' the rail joints by 1/2" or so to prevent 'dog legs' occuring
I've seen 6" using flexitrack, would agree re joints...
If you intend to have very tight radius flexi track then you will most defiantly need to pre-bend the rail to stop any stress on the plastic rail chairs as well as the rail joints.
As it happens we always pre-bend all the rails for the tighter curves on our layouts, even those at 12 or 18n inch radius. We have found that it works best if you pre-bend the rails slightly tighter than you need, especially at rail joints.
The main problem you will have with tight curves is coupling overhang. You will find that many locos and even some four wheel 009 wagons will have problems with the couplings locking on the tight curves.
I have a layout with 9 inch curves and in practical terms this is limited to locos with small coupling overhangs and to rolling stock with bogie mounted couplings. Virtually everything else causes problems. This is why the Minitrains 0-8-0 is not recommended for use with their own track, the loco will go round the tight curves, but the rear coupling overhang will pull the next vehicle off the track!
I would recommend that you experiment with the locos and rolling stock you intend to use to see what curves they can go round, remember that at some time the trains will also need to be propelled (pushed) round the curves as well.
Brian Meldon
Quote from: Hobby on June 10, 2017, 20:41
Quote from: Steve Lewis on June 10, 2017, 15:00
Carefully laid you should be able to get 7" radius, I have done about that in the past, if you have to make a joint on the curve it is best to 'stagger' the rail joints by 1/2" or so to prevent 'dog legs' occuring
I've seen 6" using flexitrack, would agree re joints...
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Staggered joints are also used on the 'real railways' on tight radius situations ( usually in yards etc) there are some photos around somewhere on RMWeb I think showing examples
Quote from: B.Meldon on June 12, 2017, 10:25
I would recommend that you experiment with the locos and rolling stock you intend to use to see what curves they can go round, remember that at some time the trains will also need to be propelled (pushed) round the curves as well.
Brian Meldon
This is the purpose of our radius test track board. You can power up each radius from 3 inch to 8 inch with crocodile clips and run a two coach/wagon train, I would agree that pushing is much more problematic than pulling and tends to lead to more derailing the tighter the curve. For our purposes it does not matter as trains only go in one direction on our automatic layouts except where there is a shuttle.
Quote from: jimowers on June 13, 2017, 00:05
Quote from: B.Meldon on June 12, 2017, 10:25
I would recommend that you experiment with the locos and rolling stock you intend to use to see what curves they can go round, remember that at some time the trains will also need to be propelled (pushed) round the curves as well.
Brian Meldon
This is the purpose of our radius test track board. You can power up each radius from 3 inch to 8 inch with crocodile clips and run a two coach/wagon train, I would agree that pushing is much more problematic than pulling and tends to lead to more derailing the tighter the curve. For our purposes it does not matter as trains only go in one direction on our automatic layouts except where there is a shuttle.
That test track sounds like a good system.
Obviously the coupling overhang is double if you have a reverse curve on a layout.
I totally agree that pulling trains is far less problematic than propelling them and on a layout where the trains cannot be reversed propelling is not a problem.
However I have an automated H0 layout with full block section signalling, and on that the trains are supposed to always go one way all the time and for 99% of the time they do. However very occasionally something will go wrong like a derailment or a vehicle uncoupling for no apparent reason and when that happens it is often required that the train involved (or part of it at least) has to be reversed.
But obviously if that is impossible on an automated layout then it will never be an issue, but in my experience on most 009 layouts you will have to propel trains at some time even if it is only for coupling or re-coupling them.
Brian Meldon
Yes, I have found the test track was really worthwhile building as so far, touch wood, I have not had any problems with rolling stock after I have gone to the great effort of building a layout.
As you can see, the test track is quite compact and offers radii from 3 inches up to 8 inches. These are more than enough and in fact 3 inch has never been used on a real layout as it is way too tight.
(https://forum.009society.com/proxy.php?request=http%3A%2F%2Fi1067.photobucket.com%2Falbums%2Fu435%2Frefinocio%2FOO9_RadiusTestTrack_zpsopyorlu8.jpg&hash=cae33c4752ffcbe725d57ca70d258a332033ac1c)
For those interested in the construction details, the base is made of 10mm foam board and the track is Peco OO9 'Crazy Track' Flexitrack which has been curved using the KBScale rail bender device. I have a Gaugemaster Combi set up with interchangeable leads, one of which are a set of crocodile clips which are just placed on to the appropriate track for testing. There was no need to include a controller into this baseboard as I only use radius checks on an infrequent basis.