Last for today. There is wine with my name on it.
The curved section which has given me plenty of anxiety turned out to be not too bad, but another interesting problem has arisen. More of that later...
I had a look at the amount of track needed for the curve which turned out to be roughly 2/3 of a length of Peco track. After some head scratching and all previous ideas binned I made it from one piece of track, cut slightly too long and then joined to the square crossing with fishplates, stuck loosely down and trimmed to length at the turntable end. It looks like this:
by , on Flickr
From outside rail to outside rail is just under 10". I've no idea how to calculate radius but it is as tight as I'd want to go without pre-bending the rails first. Power is fed in from the crossing end only as its one continuous rail. It works, too:https://youtu.be/9y2TX_ExWb4
Using a lot of jump leads to power the track, I tested running on to, off and across the turntable. Thankfully, with very careful alignment, it worked too, although there is no margin for error at all. Wagons, especially when empty, will need to be heavy and consistent in their weight to ensure reliable running. Thankfully I have plenty of lead
The original left hand siding needs to have its rail height lowered by 1/2 mm or so as it is causing occasional derailment when moving left to right on to the turntable. This should happen by fitting a sleeper and sticking it to the foam base.
The differential between the code 83 square crossing and the code 100 Peco track will be addressed with a file as there is a bit of a bump there too.
The most annoying thing is that the dead section of the square crossing matches the wheelbase of the Bachmann 0-4-0 perfectly, resulting in a stop unless travelling at speed. I refrained from harsh language once I found this, and will try to think of a cure which does not involve major track surgery. Thankfully the area in question is off scene, so if the big hand is needed its not the end of the world.
As an experiment, I tried some other 4 coupled locomotives to see if a suitable substitute would work. The Hornby "Smokey Joe" type doesn't like the radius at all (so no visits from the fireless crane or vertical boiler locomotives), a Bachmann On30 Porter 0-4-2 derails the trailing bogie. I've an 0-4-0 as well, but couldn't be *rsed didn't take the time to get it out. A Model Power Hustler also doesn't like the radius. There is a Spud in a box with some other bits which should be ok, but I can't currently find it as it was bought in January and is under some layers.
So.. that's the track down, and mostly working. I'm happy with progress today, and will let the whole thing sit until (hopefully) tomorrow evening when I'll have a look at the revised control panel. I've taken advantage of the revision caused by the new siding to move some of the text round a bit and amend the name to "Patented Olfactory Obfuscation Products (Feline) Ltd" in case there is confusion over what sort of litter it actually is. Best to be careful with these things.