Sharp radius points in OO

[hayfield]

Thanks for all your comments so far.

 

The A5 I built a couple of years ago works fine with all the tank locos that I will be running over the layout. I've now started building an A5 crossover in OO-SF and will probably install some gauge widening on the first set of points and check how that goes.

 

 

Just a thought. if you gauge widen will it be 00sf?

[Captain Kernow]

Just a thought. if you gauge widen will it be 00sf?

Well, it will be through the crossing nose area!

[nswgr1855]

Thanks for all your comments so far.

 

The A5 I built a couple of years ago works fine with all the tank locos that I will be running over the layout. I've now started building an A5 crossover in OO-SF and will probably install some gauge widening on the first set of points and check how that goes.

 

I don't understand why you want to use A5 turnouts If you want to run 0-6-0 locomotives through them. If you build an A5.25 turnout instead, it is only a few mm longer and gauge widening then is not needed. Keeping the gauge tight means less side motion at the end of models, making it look better, minimizing buffer lock. If you are making a crossover, then you have in practice close to a reverse curve. For reverse curves I would increase the turnout minimum radius by 20%. In this case an A5.5 is big enough. The crossover (2 turnouts) works out only about 7mm longer.

 

Cheers,

 

Terry Flynn.

[Captain Kernow]

I don't understand why you want to use A5 turnouts If you want to run 0-6-0 locomotives through them. If you build an A5.25 turnout instead, it is only a few mm longer and gauge widening then is not needed. Keeping the gauge tight means less side motion at the end of models, making it look better, minimizing buffer lock. If you are making a crossover, then you have in practice close to a reverse curve. For reverse curves I would increase the turnout minimum radius by 20%. In this case an A5.5 is big enough. The crossover (2 turnouts) works out only about 7mm longer.

 

Cheers,

 

Terry Flynn.

Thanks for that Terry. I've actually never heard of anyone building an 'A5.25' or an 'A5.5' turnout, although thinking about it now, I can't see any logical reason why one couldn't.

 

In fact, work has already started on the A5 crossover, being built as one unit, with one set of points completed and the other part-way through.

 

I have used the C&L three-point jigs on the diverging sections, which has resulted in very slight gauge widening. I have tested a couple of 0-6-0s through it and I am happy with the results so far.

 

My experience of operating my two existing OO layouts (not OO-SF), which also feature hand-built points, some of which are certainly A5, is that the locos I'm going to use on the new layout will have no problem running through the pointwork and buffer locking rarely happens on the two older layouts. Both layouts also effectively have a 'reverse curve' that the use of crossovers impart.

 

Over time, I have come to know which items of stock can be permitted to make certain moves, and which have to be 'prohibited'. This reduces the chances of embarrassing buffer locking and/or derailment at exhibitions.

 

In continuing to build OO layouts (I still haven't finished my first P4 one), I acknowledge that the whole thing is compromised anyway, but that's not the reason I'm building this particular layout.

 

 

Edit - I already had a set of various OO-SF paper templates that another RMWeb person had kindly provided me with a couple of years ago. These included some A5s, but clearly no A5.25s or A5.5s. It would probably take me longer to master a programme like Templot that it will take me to build the layout!