Bob the tube I use is silicone, I'm sorry, should have said so Mine came from a fishing tackle shop where it is sold for making rings that hold a float to the fishing line like a small rubber band. It is available in various diameters.
I thought it was about time that I posted a picture of the progress so far with my DeWinton style loco.
The engine has been run on air and the boiler has been tested to 5 bar and is expected to work at 2 to 3 bar. The burner is a home made intended to be fired by butane. The gear ratio is from memory 4.5:1. Some of the delay has been due to changing the original design from a free standing engine to one mounted on the side of the boiler. This I believe will help reduce the condensation problems caused while the cylinders warm up.
Hi Paul, 1,I heard about mounting the engine on the boiler from DeWinton Dave in one of his postings. 2,The bush is for a possible boiler blow-down valve. 3,Yes, the gears are home made. 4,The shim is there because I have used Clinch nuts for the mounting of both the burner and boiler. However I forgot that the Clinch nuts are not flush with the surface of the plate they are fitted to, hence the 'shim' to lift the boiler firebox ring. The boiler mounting brackets are screwed to the firebox ring using blind tapped holes. This way the fixing screws are not in the burner flames.
I have been trying to get to several exhibitions this year but have not been able to make it for various reasons but things are looking good for the Midlands one on the 20th October.