While I made my own screw link couplings for Boadicea I don't think I ever detailed making them on the thread. I shall go and have a look at my notes as I have to make a new screw link for the tender. Perrier's drawings have the length of the U too short to clear the end of the hook. I also included a gedge to allow the whole coupling to be removed.
edit: Looking at Pete's comments I know it can't have been my thread, I always come up with the most complicated way doing a task. I'll still check though.
Will wonders ever cease? I went through my files and found I had in fact kept sketches and notes for making the screw coupling. Just to clarify the ss in the second sketch refers to silver solder and the 'Alxxx' bar should read 'bar used to align the ends of the U.
Hope this all makes sense.
This is J Perrier's drawings for the screw coupling along with my notes. The 'Correct size for 5"g' is an enlargement I made to glue to a blank as a pattern to follow when cutting out.
hi arch, this thread is very relevant and so pleased you raised it! on GWR locos the drawhooks have slots for the 'U' to slide into with their eyes on the ends - but on STEPNEY the hole in the drawhooks is just over the diameter of the 'U' without the eyes on the ends if this makes sense, so i will have to silver solder the eyes on the end after slipping through the hole in the drawhook. ive never had to do this before! as per jim, ive made the eyes on each side of the 'U' a single piece relieved in the middle when silver soldering together, then cut out the relieved portion. a similar proceedure is used for the eyes on the ends of smokebox door hinges. as ben has very kindly confirmed recently for me the SR type coupling on STEPNEY has a tommy bar in the middle with a R-H and L-H thread either side. this isnt something im looking forward to! nor am i looking forward to cleaning up and repolishing the drawhooks after silver soldering the eyes to the 'U' when fitted in same! cheers, julian
hi arch, proper scale screw link couplings are a real pain! they cant be used so just for appearances sake, yet are so prominent that worth reproducing properly but they take a lot of time to make. John (simplyloco) has added/repeated his description of how he made his lovely screw couplings today on his Brit thread. i wish the SR type were as straightforward as the GWR/BR type! thanks jim for your condolances! cheers, julian
Post by fostergp6nhp on Sept 25, 2014 15:34:00 GMT
Use heat so there is no spring, it's how the full size were done.
4" Foster agricultural traction engine running and a 4" scale Foster 7NHP double crank compound showmans road loco under construction with a 5" Gauge Alco WDLR 2-6-2(Mountaineer) under construction as a gap filler.