Sunday, January 31, 2010
There are 3 issues:
1) DCC 'friendly' issues regarding shorts between point blade and stock rail.
There are more detailed sites about this such as wiring for dcc (http://www.wiringfordcc.com/) but the principles are well explained here: http://www.newrailwaymodellers.co.uk/electrics-dcc-wiring-a-layout.htm
Basically, an out of gauge wheelset may bridge the gap between a stock rail at -ve and a point blade at +ve. This causes a short, which in DC operation would just result the loco momentarily stalling before recovering. However in DCC this kind of short would reset the command station as decoders are very sensitive to shorts - the command station shuts down to protect the decoders.
I have in the past dismissed this as a minor issue as it shouldn't happen too much and I will make sure the back to backs on locos/stock are correct. Having thought about it though the plastic centred wheels with metal treads that are used almost uniformally in my stock do sometimes come apart and I can see that this shorting thing could be more of a problem that once thought.
So, it would be far better to join the stock rail to the point blade so it is the same polarity and make a cut just before the frog. The frog remains power routed and the problem is solved. Insulfrog points just need the wires carrying current over the dead frog to be cut and the blades to be linked to the stock rails. The insulfrog creates the gap and no cutting of rails is required.
In 009 peco electrofrog points are difficult due to the way that they are made. Half way along the point blade there is a rail joiner which acts as a pivot. This is within just a few chairs of the frog. So if you try and put a break in the blade as suggested the piece of rail left behind wobbles terribly and comes away at the pivot. In OO this is not such a problem as the point is considerably longer.
People have suggested filling the gap created with araldite or some non conducting filler, but this is not really a proper solution either for long term reliability.
The real solution is to find points that don't have this pivot in them. Most hand built points are not made that way and so are some others such as those made by tillig.
I am therefore carefully considering whether to dig up my peco points and either get some specially made for me (with electrofrogs) or move to insulfrog tillig points.
2) Solenoid versus latching point motors
The solenoid motors I have installed are not latching, so they don't hold the blade against the stock rail as if it were locked there.
They are also very strong in their action (although I need to do some more programming on mine as they aren't strong enough at the moment), which puts stress on the points unneccessarily. Might tortoise slow action (and latching) motors be a better bet? The problem is that these require quite some depth of baseboard. I have just under 70mm of depth, a tortoise needs 85mm - a problem!
I would also need a different type of accessory decoder too - the wabbit. http://www.dccsupplies.com/shop/product_info.php?products_id=1307
so this is getting expensive!
Seep latching motors could be a possibility too, but they only have one aux switch, causing problems for my point indicator LED wiring.
I think I'll stay with peco for now on cost grounds, but I may need one of these for extra ummph where I have set things up to throw two solenoids at once http://www.bromsgrovemodels.co.uk/masterswitchfaq.htm
3) Check rail clearances
I have never been happy with this element of peco points, which in many cases require filing to accept even the finest flanges. Tillig points are much better in this regard.
If you want to see what a tillig point looks like, check: http://www.internationalmodels.net/acatalog/Main_Catalogue_Index_Narrow_Gauge_23.html
The 'massive' problem being that they are insulfrog.
So, do we prefer DCC friendly but insulfrog tillig, over DCC unfriendly but electrofrog peco? Or should I get some hand built points that are electrofrog and DCC friendly?
Friday, January 22, 2010
In other news, the replacement wheel for Tal has arrived and so work can recommence there.
Tuesday, January 19, 2010
Moel Tryfan - http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=110483342149&ssPageName=STRK:MESELX:IT
Baldwin 590 - http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=110483393212&ssPageName=STRK:MESELX:IT
Gowrie - http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=110483395646&ssPageName=STRK:MESELX:IT
and 4415 the Kerr Stuart diesel - http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=110483397591&ssPageName=STRK:MESELX:IT
get in there quick if you want one.
Monday, January 18, 2010
A great show – a large hall with plenty of space to move about in, lots of families there, good traders (modelex and squires got most of my dollars), good layouts, superb restaurant but not much narrow gauge!
A very clever bit of scenic modelling, highlighting a frosty winter morning – Blackston Junction in P4
A work in progress of Toddington (GWSR)
And our favourite – Oulton TMD – digital sound from classes 20,31,33,37,43,45,47,50,56,60,108 and 159 plus lots of LED lighting in 00. Video at the bottom.
Iron Mould Lane – nice, very nice
This means I will be able to pass two trains of double headed NGG16s in the station - cool!
This will also mean that plans to sell Moel Tryfan, 4415, the Baldwin 590 and Gowrie will have to be accelerated. Gowrie is still a kit and I will be constructing it tonight ready for sale.
In other news, I attended the Leamington/Warwick show on Saturday - good show, report to come on this blog. I have also ordered a replacement wheel for Taliesin from alan gibson.
Monday, January 04, 2010
Christmas progress has been slow (as you would expect), news being:
- The prep for sale of the Baldwin 590 and Moel Tryfan. This included the first use of Dad's new graphic air filtration unit (shown above). During this the hairdryer we were using managed to heat the model so that the low melt solder holding the boiler unit and cab square part melted causing the body to fall out of square!
- The arrival of my CMX track cleaner and a trip to boots to get some nail varnish remover for really powerful track cleaning! [not every day, but where for example paint or hairspray overspray has got on the rail head]
- Father Christmas bringing an 08 shunter chassis for Harlech Castle with outside frames, books and also the prodigy PC interface cable.
- Attempts to retain the crankpin on Taliesin's troublesome wheel failing despite the use of powerbond and loctite 601. It seems these nylon wheel centres are not easy to glue and the crankpin hole has clearly become too large, so a new wheel must be the answer!
- The news that I must travel abroad (to Malta) for a while on work, so modelling is likely to cease for this period and thus blog updates will likely stop for a couple of weeks (sorry). Hopefully it will be hotter over there than it is here! Well looking at the forecast it looks like 18-20 degrees C in the day and 15 at night. Nice!